Essential Oil- Bearing Grasses

Essential Oil- 

Bearing Grasses 

The genus Cymbopogon

Medicinal and Aromatic Plants — Industrial Profiles 

Individual volumes in this series provide both industry and academia with in-depth coverage of 

one major genus of industrial importance. 

Series Edited by Dr. Roland Hardman 

Volume 1 

Valerian, edited by Peter J. Houghton 

Volume 2 

Perilla, edited by He-ci Yu, 

Kenichi Kosuna, and Megumi Haga 

Volume 3 

Poppy, edited by Jenö Bernáth 

Volume 4 

Cannabis, edited by David T. Brown 

Volume 5 

Neem, edited by H.S. Puri 

Volume 6 

Ergot, edited by Vladimír Kˇren and 

Ladislav Cvak 

Volume 7 

Caraway, edited by Éva Németh 

Volume 8 

Saffron, edited by Moshe Negbi 

Volume 9 

Tea Tree, edited by Ian Southwell and 

Robert Lowe 

Volume 10 

Basil, edited by Raimo Hiltunen and 

Yvonne Holm 

Volume 11 

Fenugreek, edited by 

Georgios Petropoulos 

Volume 12 

Ginkgo biloba, edited by 

Teris A. Van Beek 

Volume 13 

Black Pepper, edited by P.N. Ravindran 

Volume 14 

Sage, edited by Spiridon E. Kintzios 

Volume 15 

Ginseng, edited by W.E. Court 

Volume 16 

Mistletoe, edited by Arndt Büssing 

Volume 17 

Tea, edited by Yong-su Zhen 

Volume 18 

Artemisia, edited by Colin W. Wright 

Volume 19 

Stevia, edited by A. Douglas Kinghorn 

Volume 20 

Vetiveria, edited by Massimo Maffei 

Volume 21 

Narcissus and Daffodil, edited by 

Gordon R. Hanks 

Volume 22 

Eucalyptus, edited by 

John J.W. Coppen 

Volume 23 

Pueraria, edited by Wing Ming Keung 

Volume 24 

Thyme, edited by E. Stahl-Biskup and 

F. Sáez 

Volume 25 

Oregano, edited by Spiridon E. Kintzios 

Volume 26 

Citrus, edited by Giovanni Dugo and 

Angelo Di Giacomo 

Volume 27 

Geranium and Pelargonium, edited by 

Maria Lis-Balchin 

Volume 28 

Magnolia, edited by Satyajit D. Sarker 

and Yuji Maruyama 

Volume 29 

Lavender, edited by Maria Lis-Balchin 

Volume 30 

Cardamom, edited by P.N. Ravindran

Volume 31 

Hypericum, edited by Edzard Ernst 

Volume 32 

Taxus, edited by H. Itokawa and 

K.H. Lee 

Volume 33 

Capsicum, edited by Amit Krish De 

Volume 34 

Flax, edited by Alister Muir and 

Niel Westcott 

Volume 35 

Urtica, edited by Gulsel Kavalali 

Volume 36 

Cinnamon and Cassia, edited by 

P.N. Ravindran, K. Nirmal Babu, and 

M. Shylaja 

Volume 37 

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Volume 38 

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Volume 39 

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Sandra Carol Miller 

Assistant Editor: He-ci Yu 

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Illicium, Pimpinella and Foeniculum, 

edited by Manuel Miró Jodral 

Volume 41 

Ginger, edited by P.N. Ravindran 

and K. Nirmal Babu 

Volume 42 

Chamomile: Industrial Profiles, 

edited by Rolf Franke and 

Heinz Schilcher 

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Medicine, edited by Navindra P. 

Seeram, Risa N. Schulman, and 

David Heber 

Volume 44 

Mint, edited by Brian M. Lawrence 

Volume 45 

Turmeric, edited by P. N. Ravindran, 

K. Nirmal Babu, and K. Sivaraman

Essential Oil- 

Bearing Grasses 

The genus Cymbopogon 

Edited by Anand Akhila 

Medicinal and Aromatic Plants — Industrial Profiles

CRC Press 

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Library of Congress Cataloging-in-Publication Data 

Essential oil-bearing grasses : the genus Cymbopogon / editor: Anand Akhila. 

p. cm. -- (Medicinal and aromatic plants--industrial profiles ; v. 46) 

Includes bibliographical references and index. 

ISBN 978-0-8493-7857-7 (hardcover : alk. paper) 

1. Cymbopogon. 2. Cymbopogon--Industrial applications. 3. Cymbopogon--Therapeutic use. I. 

Akhila, Anand. II. Title. III. Series: Medicinal and aromatic plants--industrial profiles ; v. 46. 

QK495.G74E745 2010 

661’.806--dc22 2009024407 

Visit the Taylor & Francis Web site at 

http://www.taylorandfrancis.com 

and the CRC Press Web site at 

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Contents 

Preface to the Series ..........................................................................................................................ix 

Preface...............................................................................................................................................xi 

Author/Editor Page ........................................................................................................................ xiii 

Contributors .....................................................................................................................................xv 

Chapter 1 The Genus Cymbopogon: Botany, Including Anatomy, Physiology, 

Biochemistry, and Molecular Biology ..........................................................................1 

Cinzia M. Bertea and Massimo E. Maffei 

Chapter 2 Chemistry and Biogenesis of Essential Oil from the Genus Cymbopogon ...............25 

Anand Akhila 

Chapter 3 The Cymbopogons: Harvest and Postharvest Management ..................................... 107 

A. K. Pandey 

Chapter 4 Biotechnological Studies in Cymbopogons: Current Status and Future Options .... 135 

Ajay K. Mathur 

Chapter 5 The Trade in Commercially Important Cymbopogon Oils ...................................... 151 

Rakesh Tiwari 

Chapter 6 In Vitro Antimicrobial and Antioxidant Activities of Some Cymbopogon 

Species ...................................................................................................................... 167 

Watcharee Khunkitti 

Chapter 7 Thrombolysis-Accelerating Activity of Essential Oils ............................................. 185 

Hiroyuki Sumi and Chieko Yatagai 

Chapter 8 Analytical Methods for Cymbopogon Oils .............................................................. 195 

Ange Bighelli and Joseph Casanova 

Chapter 9 Citral from Lemongrass and Other Natural Sources: Its Toxicology 

and Legislation .........................................................................................................223 

David A. Moyler 

Index .............................................................................................................................................. 239 

vii

Preface to the Series 

There is increasing interest in industry, academia, and the health sciences in medicinal and aromatic 

plants. In passing from plant production to the eventual product used by the public, many sciences 

are involved. This series brings together information that is currently scattered through an everincreasing 

number of journals. Each volume gives an in-depth look at one plant genus about which 

an area specialist has assembled information ranging from the production of the plant to market 

trends and quality control. 

Many industries are involved, such as forestry, agriculture, chemical, food, flavor, beverage, 

pharmaceutical, cosmetic, and fragrance. The plant raw materials are roots, rhizomes, bulbs, 

leaves, stems, barks, wood, flowers, fruits, and seeds. These yield gums, resins, essential (volatile) 

oils, fixed oils, waxes, juices, extracts, and spices for medicinal and aromatic purposes. All these 

commodities are traded worldwide. A dealer’s market report for an item may say “drought in the 

country of origin has forced up prices.” 

Natural products do not mean safe products, and account of this has to be taken by the above 

industries, which are subject to regulation. For example, a number of plants that are approved for 

use in medicine must not be used in cosmetic products. 

The assessment of “safe to use” starts with the harvested plant material, which has to comply 

with an official monograph. This may require absence of, or prescribed limits of, radioactive material, 

heavy metals, aflatoxin, pesticide residue, as well as the required level of active principle. This 

analytical control is costly and tends to exclude small batches of plant material. Large-scale, contracted, 

mechanized cultivation with designated seed or plantlets is now preferable. 

Today, plant selection is not only for the yield of active principle, but for the plant’s ability to 

overcome disease, climatic stress, and the hazards caused by mankind. Such methods as in vitro 

fertilization, meristem cultures, and somatic embryogenesis are used. The transfer of sections of 

DNA is giving rise to controversy in the case of some end uses of the plant material. 

Some suppliers of plant raw material are now able to certify that they are supplying organically 

farmed medicinal plants, herbs, and spices. The Economic Union directive CVO/EU No. 2092/91 

details the specifications for the obligatory quality controls to be carried out at all stages of production 

and processing of organic products. 

Fascinating plant folklore and ethnopharmacology lead to medicinal potential. Examples are 

the muscle relaxants based on the arrow poison curare from species of Chondrodendron, and the 

antimalarials derived from species of Cinchona and Artemisia. The methods of detection of pharmacological 

activity have become increasingly reliable and specific, frequently involving enzymes 

in bioassays and avoiding the use of laboratory animals. By using bioassay-linked fractionation of 

crude plant juices or extracts, compounds can be specifically targeted which, for example, inhibit 

blood platelet aggregation, or have antitumor, antiviral, or any other required activity. With the assistance 

of robotic devices, all the members of a genus may be readily screened. However, the plant 

material must be fully authenticated by a specialist. 

The medicinal traditions of ancient civilizations such as those of China and India have a large 

armamentarium of plants in their pharmacopoeias that are used throughout Southeast Asia. A similar 

situation exists in Africa and South America. Thus, a very high percentage of the world’s population 

relies on medicinal and aromatic plants for their medicine. Western medicine is also responding. 

Already in Germany all medical practitioners have to pass an examination in phytotherapy before 

being allowed to practice. It is noticeable that medical, pharmacy, and health-related schools 

throughout Europe and the United States are increasingly offering training in phytotherapy. 

ix

x Preface to the Series 

Multinational pharmaceutical companies have become less enamored of the single compound, 

magic-bullet cure. The high costs of such ventures and the endless competition from “me-too” compounds 

from rival companies often discourage the attempt. Independent phytomedicine companies 

have been very strong in Germany. However, by the end of 1995, 11 (almost all) had been acquired 

by the multinational pharmaceutical firms, acknowledging the lay public’s growing demand for 

phytomedicines in the Western world. 

The business of dietary supplements in the Western world has expanded from the health store to 

the pharmacy. Alternative medicine includes plant-based products. Appropriate measures to ensure 

their quality, safety, and efficacy either already exist or are being answered by greater legislative 

control by such bodies as the U.S. Food and Drug Administration and the recently created European 

Agency for the Evaluation of Medicinal Products based in London. 

In the United States, the Dietary Supplement and Health Education Act of 1994 recognized the 

class of phytotherapeutic agents derived from medicinal and aromatic plants. Furthermore, under 

public pressure, the U.S. Congress set up an Office of Alternative Medicine, which in 1994 assisted 

the filing of several Investigational New Drug (IND) applications required for clinical trials of some 

Chinese herbal preparations. The significance of these applications was that each Chinese preparation 

involved several plants and yet was handled as a single IND. A demonstration of the contribution 

to efficacy of each ingredient of each plant was not required. This was a major step toward more 

sensible regulations in regard to phytomedicines. 

I always look forward to the journal HerbalGram (HG), of the American Botanical Council, 

which was founded by Mark Blumenthal in 1988. He continues as the Executive Director and 

as the Editor of HG. In it he regularly justifies the status of a medicinal plant and challenges 

official bodies when necessary. In HG Number 80 (2008), he tells the U.S. Food and Drug 

Administration to rescind the 1991IMPORT ALERT on the herb stevia (Vol. 19 in this series) 

because the United Nations and the World Health Organization have concluded that stevia 

extract, containing 95% stevia glycosides, is safe for human use as a sweetening agent, in the 

range 4 mg/kg body weight per day. This has paved the way for regulatory approval around the 

world for the use of this low-cost noncaloric material and notably for those obese persons facing 

cardiovascular disease and diabetes. 

For this volume, I thank its editor, Dr Anand Akhila, for his dedicated work and the chapter 

contributors for their authoritative information. My thanks are also due to Barbara Norwitz of CRC 

Press and her staff for their unfailing help. 

Roland Hardman, BPharm, BSc (Chem), PhD (London), FR Pharm S.

Preface 

The essential oils of the grasses of species of Cymbopogon have an industrial profile; they are used 

in beverages, foodstuffs, fragrances, household products, personal care products, pharmaceuticals, 

and in tobacco. 

These oils are sourced from around the world by, for example, Fuerest Day Lawson (FDL) Ltd. It 

is fascinating that this company is on the same site where plant raw material has arrived for the past 

400 years—close to the Tower of London and the River Thames. No longer in a warehouse but in a 

modern tower block, FDL has all the equipment to test the efficacy of an essential oil for a particular 

purpose. For the producer of the oil, FDL will advise on the development of a modern production 

process (in the country of origin if required), even to the stage of the final saleable product. 

FDL’s technical director, David A. Moyler, regularly attends meetings of the European Union 

in Brussels concerned with the regulations covering the commercial production and sale of such 

products, and he has contributed a relevant chapter to this book. 

The genus Cymbopogon (family Gramineae) has many species of grasses that grow in tropical 

and subtropical regions around the world from mountains to grasslands to arid zones. These plants 

produce essential oils with pleasant aromas in their leaves. 

Five species yield the three oils of main commercial importance: lemongrass from C. citratus of 

Malaysian origin (West Indian lemongrass) and C. flexuosus (East Indian lemongrass) from India, 

Sri Lanka, Burma, and Thailand; palmarosa oil from C. martinii; citronella oil from C. nardus (Sri 

Lanka), and C. winterianus (Java). 

This book describes the considerable ethno-botanical, phytochemical, and pharmacological 

knowledge that is associated with the multidimensional uses of the oils of the cymbopogons. 

Lemongrass originated in Asia and is an ingredient of its herbal teas, soups, and innumerable 

other food recipes found in South East Asia, Cambodia, and Vietnam. In Europe the oil is used in 

spiced wines and herbal beers. Citronella oil gives a pleasant, refreshing aroma to personal care 

products including mosquito repelling lotions, etc. Palmarosa oil supplies a rose note to fine perfumes 

and to, for example, perfumed candles and herbal pillows. These last two oils may result in a 

higher income for a farmer than from the traditional food crops. 

Extraction of the oils is by steam distillation and the aqueous distillates (hydrosols), after separation 

of the oils, are said to have antiviral, antibacterial, and antifungal properties. The spent grass, 

after the extraction of the oil, is used as a cattle fodder, or for paper making, or as a fuel in the next 

round of distillation. 

These oils are a source of precursors for the production of vitamin A and potentially for other 

compounds; as “green” factories these plants provide alternative synthetic routes to the petrochemical 

ones. 

For those in academia, both teachers and research students, those in agriculture and other industries, 

and those in business, this book provides an account of the botany, taxonomy, chemistry, and 

biogenesis of the oils, and their extraction and analytical methods, biotechnology, storage, legislation, 

and trade with all the accompanying references. 

Professor Massimo Maffei is already a notable contributor to this series having edited a 

related Graminea volume (20), Genus Vetiveria, and contributed chapters to several other volumes. 

I thank him and all the other contributors for their kind cooperation with me and particularly for 

their expert data. My special thanks are due to Dr. Roland Hardman for his continuous encouragement 

from the very beginning of writing this book, despite his busy schedule. His help and persistent 

enthusiasm have been a great inspiration to me. 

Anand Akhila 

M.Sc., Ph.D. (University of London) 

xi

Author/Editor Page 

Dr. Anand Akhila was born in 1955. He has an outstanding 

academic career, obtaining his Ph.D. from 

University College London in 1980 in the area of Natu 

ral Product Chemistry, particularly the biosynthetic 

pathways occurring in nature. For the last 27 years he 

has been working as a senior scientist at the Central 

Institute of Medicinal and Aromatic Plants, a reputed 

national laboratory of the government of India. During 

the course of his long career, he has published over 

60 research papers, book chapters, and review articles, 

besides giving presentations at symposia and conferences. 

Anand Akhila was presented with the CSIR 

Young Scientist Award in 1988, a national honor in recognition 

of outstanding work, awarded by the Council 

of Scientific and Industrial Research, the premier scientific 

organization of the government of India. He is 

a Member of the Royal Society of Chemistry, United 

Kingdom, and many other Indian scientific societies. 

His current area of research has been the study of 

metabolic pathways of compounds of medicinal and 

aromatic values in plants such as Azadirachta indica, Artemisia annua, Cymbopogon species, 

Mentha species, and others. 

xiii

Contributors 

Anand Akhila 

Central Institute of Medicinal and Aromatic 

Plants 

Lucknow, India 

Cinzia M. Bertea 

Department of Plant Biology and Centre of 

Excellence CEBIOVEM 

Turin, Italy 

Ange Bighelli 

Equipe Chimie-Biomasse 

Université de Corse 

Ajaccio, France 

Joseph Casanova 

Equipe Chimie-Biomasse 

Université de Corse 

Ajaccio, France 


Faculty of Pharmaceutical Sciences 

Khon Kaen University 

Massimo E. Maffei 

Department of Plant Biology and Centre of 

Excellence CEBIOVEM 

Turin, Italy 


Division of Plant Tissue Culture 


Plants (CIMAP) 



Fuerst Day Laws on Ltd 

London, U.K. 

A. K. Pandey 

Tropical Forest Research Institute 

(Indian Council of Forestry Research and 

Education) 

NWFP Division, Tropical Forest Research 

Institute 

Jabalpur, India 

Chieko Yatagai 

Kurashiki University of Science and the Arts 

Department of Physiological Chemistry 

Kurashiki, Japan 

Hiroyuki Sumi 

Kurashiki University of Science and the Arts 

Department of Physiological Chemistry 

Kurashiki, Japan 

Rakesh Tiwari 


Plants 


xv

1 

contents 

1.1 IntroductIon 

The Genus Cymbopogon 

Botany, Including Anatomy, 

Physiology, Biochemistry, 

and Molecular Biology 

Cinzia M. Bertea and Massimo E. Maffei 

1.1 Introduction ..............................................................................................................................1 

1.2 Anatomy ...................................................................................................................................4 

1.2.1 General Considerations .................................................................................................4 

1.2.1.1 Leaf Anatomy ................................................................................................5 

1.3 Biochemistry .............................................................................................................................7 

1.3.1 Characterization of the Photosynthetic Variant ............................................................8 

1.3.2 NADP + Inhibition of NADP-MDH ...............................................................................9 

1.3.3 pH and Temperature Dependence of NADPH-MDH and NADP-ME .........................9 

1.3.4 CO 2 Assimilation and Stomatal Conductance ............................................................ 10 

1.4 Molecular Biology .................................................................................................................. 11 

1.4.1 Randomly Amplified Polymorphic DNA (RAPD) Markers ...................................... 11 

1.4.2 Simple Sequence Repeat Markers (SSRs) .................................................................. 13 

1.5 Physiology and Ecophysiology ............................................................................................... 14 

1.5.1 Cymbopogon martinii ................................................................................................. 14 

1.5.2 Cymbopogon flexuosus ............................................................................................... 16 

1.5.3 Cymbopogon winterianus ........................................................................................... 17 

1.5.4 Other Cymbopogon Species ....................................................................................... 18 

References ........................................................................................................................................20 

Among monocots forming the family of Gramineae some grasses produce essential oils that are 

a valuable source for the flavor industry. Two grasses are known for their industrial potential for 

essential oil production: Vetiveria zizanioides Stapf, which has been the subject of a monograph in 

the series Medicinal and Aromatic Plants—Industrial Profiles (Maffei 2002) and Cymbopogon, 

which is the subject of this book and which updates the monograph edited by Kumar et al. (2000). 

Cymbopogon is a genus comprising about 180 species, subspecies, varieties, and subvarieties. It 

is native to warm temperate and tropical regions of the Old World and Oceania. Table 1.1 lists the 

several species, subspecies, varieties, and subvarieties as reported by the International Plant Names 

Index (2004), published on the Internet http://www.ipni.org (accessed September 10, 2007). 

The name Cymbopogon was introduced by Sprengel in 1815 (Sprengel 1815) and at that time 

the genus consisted of a few species, which were then moved to the genus Andropogon. In fact, 

both Cymbopogon and Andropogon belong to the tribe Andropogoneae, a monophyletic tribe that 

1

2 Essential Oil-Bearing Grasses: The Genus Cymbopogon 

table 1.1 

list of Cymbopogon species, subspecies, Varieties, and subvarieties as reported 

in the International Plant names Index (2004) 

Cymbopogon acutispathaceus De Wild C. exaltatus A. Camus. 

C. afronardus Stapf C. exaltatus var. ambiguus Domin. 

C. ambiguus A. Camus. C. exaltatus var. exaltatus (RBr) Domin. 

C. andongensis Rendle C. exaltatus var. genuinus Domin. 

C. angustispica Nakai C. exaltatus var. gracilior Domin. 

C. annamensis A. Camus. C. exaltatus var. lanatus (RBr) Domin. 

C. arabicus Nees ex Steud. C. exarmatus Stapf 

C. arriani Aitch. C. excavatus Stapf 

C. arundinaceus Schult. C. familiaris De Wild 

C. bagirmicus Stapf C. figarianus Chiov. 

C. bassacensis A. Camus. C. filipendulus Rendle 

C. bequaertii De Wild C. finitimus Rendle 

C. bhutanicus Noltie C. flexuosus Stapf 

C. bombycinus A. Camus. C. flexuosus var. assamensis S.C. Nath and K.K. Sarma 

C. bombycinus var. bombycinus (RBr) Domin. C. floccosus Stapf 

C. bombycinus var. townsvillensis Domin. C. foliosus Roem and Schult. 

C. bombycinus var. typicus Domin. C. gazensis Rendle 

C. bracteatus Hitchcock C. gidarba [Buch–Ham. ex Steud.] Haines 

C. caesius (Hook and Arn.) Stapf C. giganteus Chiov. 

C. caesius subsp. giganteus (Chiov) Sales C. glandulosus Spreng. 

C. calcicola C.E. Hubb. C. glaucus Schult. 

C. calciphilus Bor C. globosus Henrard. 

C. cambodgiensis E.G. Camus and A. Camus C. goeringii A. Camus 

C. chevalieri A. Camus C. goeringii var. hongkongensis S. Soenarko 

C. chrysargyreus Stapf C. gratus Domin. 

C. circinnatus Hochst. ex Hookf. C. hamatulus A Camus 

C. citratus Stapf C. hirtus Stapf ex Burtt Davy 

C. citriodorus Link C. hirtus subsp. villosum (Pignatti) Pignatti 

C. claessensii Robyns C. hispidus Griff. 

C. clandestinus Stapf C. hookeri (Munro ex Hackel) Stapf ex Bor 

C. coloratus Stapf C. humboldtii Spreng. 

C. commutatus Stapf C. iwarancusa Schult. 

C. commutatus var. jammuensis (Gupta) H.B. Naithani C. jinshaensis R. Zhang and C.H. Li 

C. condensatus Spreng. C. jwarancusa subsp. olivieri (Boiss.) S. Soenarko 

C. confertiflorus Stapf C. kapandensis De Wild 

C. connatus Chiov. C. khasianus (Hackel) Stapf ex Bor 

C. cyanescens Stapf C. ladakhensis B.K. Gupta 

C. cymbarius Rendle. C. lanatus Roberty 

C. densiflorus Stapf C. laniger Duthie 

C. dependens B.K. Simon C. lecomtei Rendle 

C. dieterlenii Stapf ex Phillips C. lepidus (Nees) Chiov. 

C. diplandrus De Wild. C. liangshanensis S.M. Phillips and S.L. Chen 

C. distans (Nees ex Steud.) Will Watson. C. lividus (Thwaites) Willis 

C. divaricatus Stapf C. luembensis De Wild 

C. eberhardtii A. Camus. C. mandalaiaensis Soenarko 

C. effusus A. Camus. C. marginatus Stapf ex Burtt Davy 

C. elegans Spreng. C. martinii Stapf

The Genus Cymbopogon 3 

table 1.1 (continued) 

list of Cymbopogon species, subspecies, Varieties, and subvarieties as reported 

in the International Plant names Index (2004) 

C. martinianus Schult. C. pruinosus Chiov. 

C. mekongensis A. Camus C. pubescens (vis) Fritsch. 

C. melanocarpus Spreng. C. queenslandicus S.T. Blake 

C. micratherus Pilg. C. quinhonensis (A. Camus) S.M. Phillips and S.L. Chen 

C. microstachys (Hookf.) S. Soenarko 

[transferred to Andropogon (Phillips and Hua 2005)] 

C. microthecus A. Camus C. ramnagarensis B.K. Gupta 

C. minor B.S. Sun and R. Zhang ex S.M. Phillips and S.L. Chen C. rectus A. Camus 

C. minutiflorus S. Dransf. C. reflexus Roem and Schult. 

C. modicus De Wild C. refractus A. Camus 

C. motia B.K. Gupta C. rufus Rendle 

C. munroi (C.B. Clarke) Noltie C. ruprechtii Rendle 

C. nardus (L.) Rendle C. scabrimarginatus De Wild 

C. nardus subvar. bombycinus (R.Br.) Roberty C. schimperi Rendle 

C. nardus var. confertiflorus (Steud.) Stapf ex Bor C. schoenanthus Spreng. 

C. nardus subvar. exaltatus (R.Br.) Roberty C. schoenanthus subsp. velutinus Cope 

C. nardus subvar. grandis Roberty. C. schultzii Roberty 

C. nardus subvar. lanatus (R.Br.) Roberty C. sennaarensis Chiov. 

C. nardus var. luridus (Hookf.) Gavade and M.R. Almeida C. setifer Pilg. 

C. nardus subvar. procerus (R.Br.) Roberty C. siamensis Bor 

C. nardus subvar. refractus (R.Br.) Roberty C. solutus Stapf 

C. nardus subvar. schultzii Roberty C. stipulatus Chiov. 

C. nervatus A. Camus C. stolzii Pilg. 

C. nyassae Pilg. C. stracheyi (Hookf.) Raizada and Jain 

C. obtectus S.T. Blake C. strictus Bojer. 

C. olivieri (Boiss.) Bor C. stypticus Fritsch. 

C. osmastonii R. Parker C. suaveolens Pilger 

C. pachnodes (Trin.) Will Watson C. subcordatifolius De Wild 

C. papillipes (Hochst. ex A. Rich) Chiov. C. tamba Rendle 

C. parkeri Stapf C. tenuis Gilli 

C. pendulus Stapf C. thwaitesii (Hookf.) Willis 

C. phoenix Rendle C. tibeticus Bor 

C. pilosovaginatus De Wild C. tortilis (Presl.) A. Camus 

C. pleiarthron Stapf C. tortilis subsp. goeringii (Steud.) TKoyama 

C. plicatus Stapf C. traninhensis (A. Camus) SSoenarko 

C. plurinodis Stapf ex Burtt Davy C. transvaalensis Stapf ex Burtt Davy 

C. polyneuros Stapf C. travancorensis Bor 

C. pospischilii (K. Schum) C.E. Hubb C. tungmaiensis L. Liu 

C. princeps Stapf C. umbrosus Pilg. 

C. procerus A. Camus C. validus Stapf ex Burtt Davy 

C. procerus var. genuinus Domin. C. vanderystii De Wild 

C. procerus var. procerus (R.Br.) Domin. C. versicolor (Nees ex Steud.) Will Watson 

C. procerus var. schultzii Domin. C. virgatus Stapf ex Rhind. 

C. prolixus (Stapf) Phillips C. virgatus Stapf ex Bor 

C. prostratus Sweet C. welwitschii Rendle 

C. proximus Stapf C. winterianus Jowitt 

C. proximus var. sennarensis (Hochst.) Tackholm C. xichangensis R. Zhang and B.S. Sun 

Source: Published on the Internet http://www.ipni.org [accessed September 10, 2007].


includes 85 genera. Mathews and coworkers (2002) found strong support for a core Andropogoneae 

that includes, among others, Andropogon and Cymbopogon, and support for its relationship with an 

expanded Saccharinae that includes Microstegium. The limited difference in the plant traits between 

Andropogon and Cymbopogon, has argued the possibility that species belonging to Cymbopogon 

might be a subgenus of Andropogon. Most of Andropogoneae have pairs of spikelets in the inflorescence, 

one sessile and one on a pedicel, although in some species one or the other of these spikelets 

appear to be suppressed. The inflorescences form is also highly variable (Mathews et al. 2002). 

Morphologically, the main difference in the genus Cymbopogon is the presence of some pair of 

spikelets, for each spike, with unisexual male flowers, whereas in the Andropogon spikelets are 

usually sessile and often sterile. Cymbopogon plants are tall (up to and above 1 m) perennial plants, 

with narrow and long leaves that are mostly characterized by the presence of silica thorns aligned 

on the leaf edges. Leaves bear glandular hairs, usually each with a basal cell that is wider than the 

distal cell (see Section 1.2). Representative of the Andropogoneae exhibit C 4 photosynthesis, with 

NADP-ME as the primary decarboxylating enzyme (Mathews et al. 2002), they usually have a chromosome 

number of five, with ploidy levels ranging from tetraploids to 24-ploid. Polyploidy, either 

as alloploidy or segmental alloploidy, is frequent. Representative specimens of various species of 

the genus Cymbopogon have been cytogenetically studied by Spies and coworkers (Spies et al. 

1994). The monophyly of Cymbopogon has also been clearly demonstrated, and the genus is sister 

to Heteropogon (Mathews et al. 2002). 

Among the several aromatic species belonging to the genus Cymbopogon the most important 

in terms of essential oil production are C. martinii, also known as palmarosa; C. citratus, better 

known as lemongrass; and the so-called East Indian lemongrass, Cymbopogon flexuosus, native to 

India, Sri Lanka, Burma, and Thailand; whereas, for the related West Indian C. citratus, a Malesian 

origin is generally assumed. C. nardus and C. winterianus produce the famous citronella from Sri 

Lanka and Java, respectively. Also known to produce essential oils are C. schoenanthus, or camel 

grass; C. caesius, or inchi/kachi grass; C. afronardus, C. clandestinus; C. coloratus; C. exaltatus; 

C. goeringii; C. giganteus; C. jwarancusa; C. polyneuros; C. procerus; C. proximus; C. rectus; 

C. sennaarensis; C. stipulatus; and C. virgatus (Guenther 1950b). The main constituents of 

Cymbopogon essential oils will be described in other chapters of the book. 

Many laboratories in several countries are deeply involved in studying various aspects of cymbopogons, 

using variously derived genetic resources. The work already done covers a wide array of 

topics, including botanical identification, plant description, cytogenetics, and cell, tissue, and organ 

in vitro cultures. Physiology and biochemistry of stress tolerance and essential oil biosynthesis, 

genetics and biotechnology, and agrotechnology involved in crop production and disease and pest 

control chemistry of terpenes, biological activities of essential oil terpenoids and trade and marketing 

aspects (reviewed by Kumar et al. 2000). 

The major objective of this monograph is to update the literature and give references on the aforementioned 

topics of cymbopogons, with particular attention to industrial aspects. In the following 

sections of this introductory chapter, we will explore the anatomy and biochemistry of the photosynthetic 

apparatus, also considering the most recent advances in molecular biology of Cymbopogon. 

We will conclude the chapter with some physiological and ecophysiological considerations. 

1.2 anatomy 

1.2.1 Ge n e r a l Co n s i d e r at i o n s 

Higher plants can be divided into two groups, C 3 and C 4, based on the mechanism utilized for photosynthetic 

carbon assimilation related to anatomical and ultrastructural features. A cross section 

of a typical C 3 leaf reveals essentially one type of photosynthetic, chloroplast-containing cell, the 

mesophyll, and in these plants atmospheric CO 2 is fixed directly by the primary carbon-fixation 

enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). In contrast, a typical C 4 leaf


has two distinct chloroplast-containing cell types, the mesophyll and the bundle sheath (or Kranz) 

cells, and they differ in photosynthetic activities (Hatch 1992; Maurino et al. 1997). The operation 

of the C 4 photosynthetic mechanism requires the cooperative effort of both cell types, connected by 

an extensive network of plasmodesmata that provides a pathway for the flow of metabolites between 

the cells. 

The C 4 pathway is a complex adaptation of the C 3 pathway that overcomes the limitation of photorespiration 

and is found in a diverse collection of species, many of which grow in hot climates. It 

was first discovered in tropical grasses (e.g., sugarcane and maize) and is now known to occur in 

16 plant families. It occurs in both monocotyledonous and dicotyledonous plants, and is particularly 

prominent in species of the Gramineae, Chenopodiaceae, and Cyperaceae (Edwards and Walker 

1983). About half of the species of the Poaceae are included among the C 4 plants (Smith and Brown 

1973). The key feature of C 4 photosynthesis is the compartmentalization of activities into two specialized 

cell and chloroplast types. Rubisco and C 3 photosynthetic carbon reduction (PCR) cycle 

are found in the inner ring of bundle sheath cells. These cells are separated from the mesophyll 

and from the air in the intercellular spaces by a lamella that is highly resistant to the diffusion of 

CO 2 (Hatch 1988). Thus, by virtue of this two-stage CO 2 fixation pathway, the mesophyll-located 

C 4 cycle acts as a biochemical pump to increase the concentration of CO 2 in the bundle sheath an 

estimated 10-fold over atmospheric concentrations. The net result is that the oxygenase activity of 

Rubisco is effectively suppressed, and the PCR cycle operates more efficiently. 

C 4 plants have two chloroplast types, each found in a specialized cell type. Leaves of C 4 plants 

show extensive vascularization, with a ring of bundle sheath (BS) cells surrounding each vein and 

an outer ring of mesophyll (M) cells surrounding the bundle sheath. CO 2 fixation in these plants is 

a two-step process. 

There are three variants on the basic C 4 pathway, and the biochemical distinctions are correlated 

with the ultrastructural differences of Kranz cells (Gutierrez et al. 1974; Hatch et al. 2007; Hatch 

et al. 1975). The three C 4 variants can be distinguished ultrastructurally by using combinations 

of two characters of bundle sheath cell chloroplasts, by the degree of granal stacking, and by the 

chloro plasts position (Gutierrez et al. 1974). 

For this reason, comparative grass leaf anatomy has become the object of intensive investigation 

in relation to photosynthesis along with biochemical studies. 

1.2.1.1 leaf anatomy 

First descriptions of the genus Cymbopogon were given by Breakwell (1914) on C. bombycinus 

and C. refractus under the name of Andropogon bombycinus R. Br. and A. refractus, respectively, 

followed by a leaf structure description done by Vickery (1935) and Prat (1937). Further studies were 

con ducted by Metcalfe (1960). The descriptions given by these authors are very similar and still valid. 

1.2.1.1.1 Generic Characters 

Both adaxial and abaxial epidermises of Cymbopogon species contain short-cells, over the veins, 

solitary, paired or in short or long rows, the proportion of each type varying with the species. Silica 

bodies are located over the veins, mostly crossed to dumbell shaped. Microhairs are present usually 

each with the basal cell wider than the distal cell, the latter frequently tapering to a pointed apex, 

or hemispherical. Stomata with subsidiary cells range from low or tall dome-shaped to triangular, 

the proportions of each type varying in different species and sometimes in separate preparations 

from a single species. The vascular bundles are small, mostly angular, but less conspicuous in some 

species than in others. The mesophyll presents a distinctly radial chlorenchyma. Bundle sheaths are 

single (Metcalfe 1960). 

Figure 1.1A shows an electron scanning micrograph of a C. citratus leaf blade. It is possible to 

observe developed prickle hairs with rather elongated bases over the veins. The abaxial epidermis 

also reveals several stomata, with narrow guard cells associated with subsidiary cells, typical of 

grasses (Figure 1.1B).


A 

C 

E 

G 

FIgure 1.1 (A) Electron scanning micrograph of C. citratus leaf blade. Prickle hairs are evident on the 

veins (white arrows) (80×). (B) Electron scanning micrograph of a stoma seen from the surface. Guard cells 

are narrow in the middle and enlarged at the end, while subsidiary cells are triangular (2000×). (C) Semi-thin 

cross section of C. citratus leaf stained with toluidine blue. The vascular bundle in a minor vein is surrounded 

by a layer of sheath cells, with chloroplasts arranged in a centrifugal position. (D) Bundle sheath chloroplast 

without grana and with few starch grains. (E) Mesophyll chloroplast with most of the thylakoid stacked in 

grana and without starch grains. (F) Bundle sheath chloroplast showing immunolabeling against Rubisco. 

Colloidal gold particles (white arrows in the high magnification) strongly label the stroma. (G) Enlargement 

of plasmodesmata connecting mesophyll and bundle sheath cells, providing metabolite flow between the two 

photosynthetic tissues. 

B 

D 

F


1.2.1.1.1.1 Leaf Ultrastructure of Cymbopogon citratus The structure of parenchymatic bundle 

sheath (BS) cells is particularly important in distinguishing C 3 and C 4 species. A commonly mentioned 

anatomical feature of C 4 plants is the orderly arrangement of mesophyll cells with reference 

to the BS, the two together forming concentric layers around the vascular bundle. The anatomical 

differences between plants exhibiting a C 4 photosynthetic carbon assimilation pathway can be 

disclosed by electron microscopical observations of the BS (Chapman and Hatch 1983; Edwards 

and Walker 1983; Gutierrez et al. 1974; Hatch 1988; Hatch et al. 1975; Jenkins et al. 1989). In the 

NADP-ME type, chloroplasts are peripherally arranged and grana are deficient or absent in bundle 

sheath cells. Two other distinctive features are the presence or absence of a mestome sheath, a layer of 

cells intervening between metaxylem vessel elements and laterally adjacent BS Kranz cells, and the 

presence or absence of a cell wall suberized lamella (SL). The mestome sheath occurs in NAD-ME 

and PCK species, while the SL is present in bundle sheath cell walls of several NADP-ME and PCK 

species (Eastman et al. 1988; Hattersley and Watson 1976). The number of mitochondria in the 

NADP-ME subtype is lower than in the NAD-ME one because, in the latter, the enzymes involved 

in the transformation of aspartate to CO 2 and pyruvate are present in these organelles (Hatch et al. 

1975). Anatomical studies conducted on C. citratus leaves indicated the presence of the C 4 Kranz 

anatomy in this plant along with several ultrastructural features typical of NADP-ME species. 

In C. citratus cross sections of minor veins, the vascular bundle appears surrounded by one layer 

of sheath cells, in which the chloroplasts are located in a centrifugal position (Figure 1.1C). No 

mestome sheath between metaxylem vessel elements and laterally adjacent Kranz cells is observed. 

In the bundle sheath, ultrastructural analyses show a suberized cell wall lamella, and the presence 

of agranal chloroplasts, containing numerous starch grains (Figure 1.1D). Figure 1.1E shows mesophyll 

chloroplasts with most of the thylakoids stacked in grana. The two photosynthetic tissues are 

connected by a certain number of plasmodesmata that provide a pathway for the flow of metabolites 

between the mesophyll and bundle sheath cells (Figure 1.1G). 

These observations are in accordance with previous anatomical descriptions related to the genus 

Cymbopogon reported by Rajendrudu and Das (1981). These authors reported on the leaf anatomy 

and photosynthetic carbon assimilation in five species of Cymbopogon (C. flexuosus, C. martinii var. 

motia, C. nardus, C. pendulus, and C. winterianus) a Kranz-type leaf anatomy with a centrifugal 

position of starch-containing chloroplasts in the bundle sheath cells. Starch was exclusively localized 

in the bundle sheath cells that were typically elongated parallel to the veins and nearly twice 

as long as wide in the species of Cymbopogon. A narrow leaf interveinal distance was a common 

feature among the five Cymbopogon species. A xylem-mestome sheath of cells between metaxylem 

vessels and laterally adjacent bundle sheath cells of primary vascular bundles was totally absent in 

the five Cymbopogon species (Rajendrudu and Das 1981). 

1.2.1.1.2 Rubisco Immunolocalization 

High-resolution immunolocalization of Rubisco by electron microscopy showed that labeling 

occurred only in the bundle sheath chloroplasts of C. citratus. For these experiments, purified rabbit 

polyclonal antibodies raised against Rubisco were employed. Bound antibodies were then visualized 

by linking conjugated gold-labeled goat antirabbit polyclonal antibodies. Gold particles 

appeared to be uniformly distributed throughout the stroma (Figure 1.1F). These studies conducted 

on C. citratus leaves provide evidence for the localization of Rubisco in the stroma of bundle sheath 

chloroplasts, as expected for a C 4 plant (Bertea et al. 2003). 

1.3 bIochemIstry 

In a preliminary physiological study conducted by (Maffei et al. 1988) on C. citratus grown in 

humid temperate climates, some of the PEP-carboxylase kinetic characteristics, and Rubisco and 

glycolate oxidase activities were found to be comparable to those of C 4 plants.


The C 4 mechanism was also confirmed by the 13 C/ 12 C stable isotope ratio analyses (δ 13 C = 

−13.0). These results are in accordance with δ 13 C values measured on other species of Cymbopogon 

(Rajendrudu and Das 1981) in which δ 13 C value of −11.0 for C. flexuosus, −9.7 for C. martinii, −11.6 

for C. nardus, −10.3 for C. pendulus, and −11.3 for C. winterianus, respectively, were recorded. 

From a biochemical point of view, the three types of the basic C 4 pathway differ mainly in the 

C 4 acid transported into the bundle sheath cells (malate and aspartate) and in the way in which 

it is decarboxylated; they are named (based on the enzymes that catalyse their decarboxylation) 

NADP-dependent malic enzyme (NADP-ME) found in the chloroplasts, NAD-dependent malic 

enzyme (NAD-ME) found in mitochondria, and phosphoenolpyruvate (PEP) carboxykinase (PCK), 

found the cytosol of the bundle sheath cells (Edwards and Walker 1983; Ghannoum et al. 2001; 

Hatch et al. 1975; Jenkins et al. 1989; Huang et al. 2001). Furthermore, a characteristic leaf anatomy, 

biochemistry, and physiology are associated with each of the C 4 types (Dengler and Nelson 1999; 

Hattersley and Watson 1976). A clear indication of the C 4 photosynthetic pathway of C. citratus and 

the variant to which it belongs was obtained by estimating the activities of NADP-ME (EC 1.1.1.40), 

NADP-MDH (EC 1.1.1.82), PPDK (EC 2.7.9.1), NAD-ME (EC 1.1.1.39), and PCK (EC 4.1.1.49) as 

well as some kinetic characteristics of NADP-ME and NADP-MDH. Adaptation to a particular 

environment is a complex process involving a number of physiological, morphological, and ecological 

factors (Ghannoum et al. 2001; Huang et al. 2001). 

Therefore, enzyme activities were recorded at the low and high temperatures typical of humidtemperate 

climates, in order to evaluate the adaptability of C. citratus. In order to estimate increases 

or decreases in the reaction rate due to changes in the protonation state, groups involved in the catalysis 

and/or binding of substrates as a consequence of pH fluctuations, activities were also recorded 

at different pH values. 

1.3.1 Ch a r a C t e r i z at i o n o f t h e Ph o t o s y n t h e t i C Va r i a n t 

Further studies dealing with the characterization of the C 4 variant indicated an NADP-dependent 

malic enzyme photosynthetic pathway in C. citratus. 

The biochemical subtype was established through the estimation of the highest activities of 

NADP-dependent malic enzyme (NADP-ME, EC 1.1.1.40), NADP-dependent malate dehydrogenase 

(NADP-MDH, E.C. 1.1.1.82), pyruvate, orthophosphate dikinase (PPDK, E.C. 2.7.9.1), NADdependent 

malic enzyme (NAD-ME, E.C. 1.1.1.39), and phosphoenolpyruvate carboxykinase (PCK, 

E.C. 4.1.1.49) and some kinetic, along with some chemical-physical parameters of NADP-ME and 

NADP-MDH. 

Extraction and partial purification sequentially involved precipitation with crystalline ammonium 

sulfate, dialysis, and anion exchange (DEAE-Sephacell). Both, extraction and assays were 

conducted according to Ashton (1990). The low activity values of PPDK (90.28 nKat mg −1 prot), 

PCK (


Km values obtained for OAA and NADPH (NADP-MDH) were 29.0 (±0.014) mM and 31,67 

(±0.09) mM, respectively. With regard to NADP-ME, the apparent Km values for NADP + and malate 

were 19.40 (±0.08) and 242.0 (±0.008) mM, respectively. In the case of NADP-MDH, Vmax values 

for OAA and NADPH were 12.52 (±0.021) and 14.97 (±0.012) mKat mg −1 prot, respectively. 

NADP-ME Vmax values for malate and NADP + were 8.63 (±0.507) and 18.60 (±0.007) mKat 

mg −1 prot, respectively. In general, relatively high activities of NADP-MDH and NADP-ME allowed 

a partial characterization of these enzymes and provided evidence for an NADP-ME subtype for 

C. citratus. The apparent kinetic properties of both enzymes were comparable to those of plants 

belonging to this subtype (Ashton 1990; Hatch et al. 2007; Hatch et al. 1975), and were consistent 

with a high photosynthetic activity, even when the plant was cultivated in a temperate climate. 

1.3.2 nadP + in h i b i t i o n o f nadP-Mdh 

Inhibition studies were carried out by measuring the NADP-MDH-catalyzed reaction at varying 

concentrations of NADP + and constant concentrations of OAA (1.0 mM) and NADPH (0.2 mM). 

NADP-MDH activity was increasingly inhibited by increasing NADP + concentrations. The activity 

value recorded in the presence of 0.25 mM NADP + was only 38% of the activity measured in 

absence of the oxidized coenzyme. 

In Zea mays, activation of NADP-MDH is regulated by oxidation and reduction of cysteine 

residues (thioredoxin-mediated system) (Lunn et al. 1995), and interconversion of the reduced and 

oxidized forms is influenced by the NADPH/NADP + ratio (Trevanion et al. 1997). A high NADPH/ 

NADP + ratio leads to a more active enzyme; thus, high rates of OAA reduction only occur in reduced 

conditions. The percentage of inhibition caused increasing NADP + concentration in our DEAE 

preparations was in accordance with the observations reported earlier. The relatively high activities 

of NADP-ME detected enable us to characterize the enzyme in C. citratus. A low Km value was 

calculated for free NADP + . These results confirm the high affinity of NADP + for its binding site in 

all isoforms of this enzyme (Rothermel and Nelson 1989). A higher Km value was calculated for 

malate in accordance with literature data. 

1.3.3 Ph a n d te M P e r at u r e dePendenCe o f nadPh-Mdh a n d nadP-Me 

pH studies were carried out by using a buffer system that contained an equimolar mixture of buffers 

adjusted to different pH values with KOH (Bertea et al. 2001). 

Assays were performed at different pH values, 6.0 to 10.5 for NADP-MDH, and 6.0 to 10 for 

NADP-ME, using the DEAE-preparation. Maximal activity of NADP-MDH enzyme was observed 

at pH 8.3, in agreement with the published data (Ashton 1990). An increase in activity was 

observed starting from the lowest pH value (6.0) up to pH 8.3. At pH 7.0−7.5, the activity was comparable 

to that at pH values ranging between 9.5 and 10.0. At pH 10.5 the activity was comparable 

to that recorded at pH 6.0. Temperature changes also affected the reaction rate. The influence of 

temperature on enzyme activities was determined for both NADP-MDH and NADP-ME by adding 

the substrates to standard assay mixtures equilibrated at the appropriate temperatures. The assays 

were performed by using the DEAE-preparation. Apparent activation energy was calculated from 

Arrhenius plots. 

When enzyme activity was measured using the standard assay system at temperatures ranging 

from 20°C to 49°C, maximal activity was detected at 35°C, while at 49°C activity was lower, but 

still much higher than that at 20°C, in accordance with the typical behavior of C 4 photosynthetic 

enzymes. From a linear Arrhenius plot of the data, in a temperature range from 20°C to 38°C, the 

activation energy of the reaction was calculated to be 6970.8 cal mol –1 . The highest NADP-ME 

activity was recorded at pH 8.3, in accordance with the enzyme characteristics (Edwards and


Andreo 1992), whereas at pH 10.0 the activity was higher than the activity recorded at pH 6.0 and 

6.5. With regard to temperature, maximal activity was measured at 45°C, the lowest at 20°C. Also 

in this case, activity response to temperature changes was typical of C 4 plants (Edwards and Andreo 

1992). The activation energy of the reaction, calculated in a temperature range from 20°C to 45°C, 

was 7605.2 cal mol –1 . 

Climatic conditions exert an evident effect on the physiological status of photosynthetic enzymes, 

and variations in light, temperature, moisture, etc., may influence the cytosolic and stromal pH 

(Ashton 1990). In C 4 plants, NADP-MDH has subunits of 42 kDa, and the native enzyme apparently 

occurs as either a tetramer or a dimer. The tetramer is the more active form; it is stable at alkaline 

pH values and at high temperatures (Ashton 1990). NADP-ME is a tetramer with a molecular weight 

of about 280 kDa, and it is more stable at pH values above 8.0 (Edwards and Andreo 1992). 

This enzyme exists as a dimer and a monomer, both of which are active. Differences in pH can 

dramatically alter the activities of these photosynthetic enzymes. Temperature is another critical 

parameter. When it is low, photosynthetic rates of C 4 plants may fall below those of C 3 ones. The 

response of enzyme activities to such changes depends on the photosynthetic pathway adopted, 

resulting in a different optimum range of temperatures over which the highest growth rate can be 

maintained (Fitter and Hay 1987). 

Because they originated in tropical and subtropical areas, the optimum temperature for photosynthesis 

in C 4 plants is 30°C–40°C, which is approximately 10°C higher than in C 3 plants (Leegood 

1993). However, C 4 photosynthesis is usually sensitive to low temperature; the minimum temperature 

for photosynthesis in several C 4 tropical grasses is 5°C–10°C (Casati et al. 1997). Activities at 

different temperatures and pH values of C. citratus NADP-MDH and NADP-ME indicated that this 

species is a C 4 NADP-ME plant, which is able to retain its photosynthetic mechanism even when 

cultivated in temperate climates. 

1.3.4 Co 2 as s iM i l a t i o n a n d st o M ata l Co n d u C ta n C e 

A very low compensation point (between 8 and 15 ppm CO 2) was calculated for C. citratus. This 

result is typical for a C 4 plant. Stomatal opening increased in response to CO 2 concentration up to 

157 ppm. However, at higher CO 2 values a decrease was recorded, thus indicating a clear effect 

of the CO 2-concentrating mechanism present in C 4 plants (data not shown). In order to evaluate 

changes in photosynthesis as a function of leaf age, CO 2 assimilation and stomatal conductance 

were also measured at different developmental stages of C. citratus leaves. A general increase for 

both parameters was observed, starting from primordial up to mature leaves, while a decrease in 

CO 2 assimilation and stomatal conductance was recorded in old leaves. Thus, primordial leaves 

presented the lowest CO 2 assimilation value (9.01 mmol CO 2 dm −2 s −1 ), while the highest values 

were recorded in young and mature leaves, without appreciable differences (22.71 and 23.94 mmol 

CO 2 dm −2 s −1 , respectively). With regard to stomatal conductance, the lowest value was measured in 

old leaves (55.00 mM H 2O dm −2 s −1 ), while the highest occurred in mature ones (165.27 mM H 2O 

dm −2 s −1 ). 

From a physiological point of view, the remarkable differences between the photosynthetic 

responses of C 3 and C 4 plants to CO 2 concentration become apparent when calculating the CO 2 

compensation point. In plants with CO 2-concentrating mechanisms, including C 4 plants, CO 2 

concentrations at the carboxylation sites are often saturating. Plants with C 4 metabolism have 

a CO 2 compensation point of or close to zero, reflecting their very low levels of photorespiration. 

The results obtained in C. citratus are in accordance with the values previously recorded on other 

species of Cymbopogon (Rajendrudu and Das 1981). In addition, the C 4 mechanism allows the plant 

to maintain high photosynthetic rates at lower partial CO 2 pressures in the intercellular spaces of 

the leaf, which require lower rates of stomatal conductance for a given rate of photosynthesis. For 

these reasons, measuring the CO 2 compensation point and stomatal conductance can be useful to 

distinguish between C 3 and C 4 pathways.


1.4 molecular bIology 

The morphological variation and oil characteristics of various species and varieties of Cymbopogon 

have been reported, but such information is not sufficient to precisely define the relatedness among 

the morphotypes and chemotypes. For instance, C. martinii var. sofia and C. martinii var. motia are 

morphologically almost indistinguishable, but show distinct chemotypic characteristics in terms of 

oil constituents (Guenther 1950a). Conversely, phenotypically and taxonomically well distinguishable 

species produce oils of almost identical chemical compositions, such as lemongrass oils from 

C. citratus and C. flexuosus (Khanuja et al. 2005). Such phenotypic traits, whether morphological 

or chemotypic, are basically the phenotypic expression of the genotype, while DNA markers are 

independent of environment, age, and tissue, and expected to reveal the genetic variation more 

conclusively in assessing such variations. Introgression of various traits, intermittent mutations, 

and selection through human intervention may lead to variation in chemotypic characters across 

geographical distributions (Kuriakose 1995). While natural hybridization may lead to the formation 

of morphological or chemotypic intermediates, defining taxa purely on this basis may not be appropriate. 

Molecular markers provide extensive polymorphism at DNA level used for differentiating 

closely related genotypes (Pecchioni et al. 1996) and also to find out the extent of genetic diversity 

(Jain et al. 2003). 

Different types of molecular markers have been developed and used in various plant species 

including grasses in the recent past years. 

1.4.1 ra n d o M ly aMPlified Po ly M o r P h iC dna (raPd) Ma r k e r s 

DNA-based markers such as randomly amplified polymorphic DNA (RAPD) (Welsh and 

McClelland 1990) have been employed not only for cultivar identification but also for phylogenetic 

and pedigree studies in a number of food, forage, and fiber crops (Chalmers et al. 1992; Kresovich 

et al. 1994). RAPDs have provided rare biotype specific markers in medicinal and aromatic plants 

such as vetiver (Adams and Dafforn 1997) and Artemisia annua (Sangwan et al. 1999). 

Randomly primed polymerase chain reaction provides a simple and fast approach to detecting 

DNA polymorphism, with allelic RAPD marker variations being detected as a plus or minus allele 

(Welsh and McClelland 1990). In particular, the approach provides multilocus profiling of DNA 

sequence differences of genotypes when genetic knowledge is lacking. Several studies have been 

carried out on Cymbopogon species by employing the RAPD approach. 

A study using RAPD markers was carried out by Shasany and coworkers (2000) to trace the 

ancestors of cultivar Java II within C. winterianus. The species C. winterianus Jowitt is believed to 

have originated from the well-known species C. nardus, type Maha Pengiri, referred to as Ceylonese 

(Sri Lankan) commercial citronella. It was introduced into Indonesia and became commercially 

known as the Javanese citronella. The Javanese type C. winterianus material was introduced into 

India for the commercial cultivation of this crop during 1959. Varieties of this species have been 

developed later by the use of breeding procedures from the same introduced material. The authors 

carried out a comparative analysis of the morphological characters, chemical traits (oil percentage 

and constituents), and RAPD profiles to assess the diversity and relationships among the Java 

citronella cultivated forms, which were systematically developed for their suitability to different 

climatic regions, and also their differences and similarities to the believed parent species C. nardus 

(Purseglove 1975). All these accessions were analyzed at the molecular level for the similarity and 

genetic distances through RAPD profiling, using 20 random primers. More than 50% divergence 

was observed for all the C. winterianus accessions in relation to C. nardus accession CN2. The clustering 

based on the similarity matrices showed a major cluster of six accessions, consisting of two 

subclusters. The accession C. nardus CN2 got carved out along with two C. winterianus accessions, 

CW2 and CW6. On the other hand, the accessions CW2 and CW6 demonstrated distinct identities 

compared to CN2 at the DNA level (Shasany et al. 2000).


The same approach was used by Sangwan et al. (2001) on eleven elite and popular Indian cultivars 

of Cymbopogon aromatic grasses of essential oil trade types—citronella, palmarosa, and 

lemongrass. They were characterized by means of RAPDs to discern the extent of diversity at the 

DNA level between and within the oil biotypes. Primary allelic variability and the genetic bases of 

the cultivated germplasm were computed through parameters of gene diversity, expected heterozygosity, 

allele number per locus, SENA, and Shannon’s information indices. The allelic diversity 

was found to be in this order: lemongrass > palmarosa > citronella. Lemongrasses displayed higher 

(1.89) allelic variability per locus than palmarosa (1.63) and citronella (1.40). Also, RAPDs of diagnostic 

and curatorial importance were discerned as “stand-along” molecular descriptors. Principal 

component analysis (PCA) resolved the cultivars into four clusters: one each of citronella and palmarosa, 

and two of lemongrasses (one of C. flexuosus and another of C. pendulus and its hybrid 

with C. khasianus). Proximity of the two species-groups of lemongrasses was also revealed as they 

shared the same dimension in the three-dimensional PCA (Sangwan et al. 2001). 

The same authors analyzed the elite and popular cultivars of C. martinii for genomic and 

expressed molecular diversity using RAPD, enzyme, and SDS-PAGE protein polymorphisms. The 

allelic score at each locus of the enzymes, as well as presence and absence profiling in RAPDs, 

and overall occurrence of band types were subjected to computation of gene diversity, expected 

heterozygosity, allele number per locus, and similarity matrix. These, in turn, provide inputs to 

derive primary account of allelic variability, genetic bases of the cultivated germplasm, putative 

need for gene/trait introgression from the wild or geographically diverse habitat in elite selections. 

‘PRC1’ possessed the highest number of unique bands based on RAPD polymorphism. In variety 

‘IW31245E,’ diaphorase and glutamate oxaloacetate transaminase isozymes generated two unique 

bands as dia-III2 and got-II4. ‘RRL(B)77’ exhibited three unique bands; one produced by esterase 

as allele est-II1 and two by malic enzyme (me-III1,3). Only one unique band was generated by 

malic enzyme in variety ‘Trishna.’ But sofia had three unique bands, two contributed by diaphorase 

(dia-II3 and dia-II4) and one by glutamate oxaloacetate transaminase (got-II2). SDS-PAGE analysis 

revealed the presence of unique polypeptide fragments (97.7 to 31.6 kDa) in varieties ‘IW31245E,’ 

‘RRL(B)77,’ ‘Tripta,’ ‘Trishna,’ ‘PRC1,’ and sofia, generated as a diagnostic marker. In general, 

molecular distinctions associated with varieties. motia and sofia were clearly noticed in C. martinii 

(Sangwan et al. 2003). 

Khanuja et al. (2005) analyzed 19 Cymbopogon taxa belonging to 11 species, 2 varieties, 1 

hybrid taxon, and 4 unidentified species for their essential oil constituents and RAPD profiles to 

determine the extent of genetic similarity and thereby the phylogenetic relationships among them. 

Remarkable variation was observed in the essential oil yield ranging from 0.3% in Cymbopogon 

travancorensis Bor to 1.2% in Cymbopogon martinii (Roxb.) Wats. var. motia. Citral, a major essential 

oil constituent, was employed as the base marker for chemotypic clustering. Based on genetic 

analysis, elevation of Cymbopogon flexuosus var. microstachys (Hook. F.) Soenarko to species status 

and separate species status for C. travancorensis Bor, which has been merged under C. flexuosus 

(Steud.) Wats., were suggested toward resolving some of the taxonomic complexes in Cymbopogon. 

The separate species status for the earlier proposed varieties of C. martinii (motia and sofia) is further 

substantiated by these analyses. The unidentified species of Cymbopogon have been observed 

as inter mediate forms in the development of new taxa (Khanuja et al. 2005). 

Somaclonal variants that arise through the tissue culture have been reported in a large number of 

species. The significance of somaclonal variation in crop improvement depends upon establishing a 

genetic basis for variation (Larkin and Scowcroft 1981). The use of the molecular marker is becoming 

widespread for the identification of somaclonal variant. In particular, RAPD markers have 

proved useful for this purpose owing to its ability to analyze DNA variation at many loci using small 

amounts of tissue (Munthali et al. 1996; Wallner et al. 1996). Screening of somaclonal variants with 

improved oil yield and quality have been reported in two species of Cymbopogon, C. winterianus 

and C. martinii (Mathur et al. 1988; Patnaik et al. 1999), but RAPDs were not used to establish


the genetic basis of this somaclonal variation. The paper of Nayak and coworkers (2003) reports the 

quantitative and qualitative analysis of selected somaclones of jamrosa (a hybrid Cymbopogon) in 

the field, screening and selection of agronomically useful somaclonal variants with high oil yield 

and desirable quality, and detection of gross genetic changes through RAPD analysis. 

In this study, the high oil yield somaclonal variants SC1 and SC2 were subjected to RAPD analysis 

and the result was compared with RAPD profile of the control. A total of 22 arbitrary primers 

were utilized for initial screening for their amplifying ability. Of these, 12 primers successfully 

amplified jamrosa DNA with reproducible banding pattern. In general, 2-11 amplified fragments 

were scored, depending upon primers, ranging in molecular sizes from 266 bp to 1.9 Kb. The test 

samples SC1, SC2, and the control could be suitably distinguished by the presence of specific markers 

or by their absence. Out of the two somaclones analyzed, relatively less distinctness in the amplified 

DNA of SC2 was detected using the primers tested. Banding pattern of this somaclone SC2 

and the control plant was similar whereas in other variants, somaclone (SC1) DNA polymorphism 

was observed by having distinct banding pattern. As indicated by RAPDs gross genetic changes 

have occurred in somaclone (SC1). The results obtained by Nayak and coworkers are in agreement 

with detection of somaclonal variants by RAPD analysis in Populus deltoides (Rani et al. 1995), 

garlic (Al-Zahim et al. 1999) and in rice (Yang et al. 1999). Taylor et al. (1995) also reported that 

RAPD analysis proved suitable for detecting gross genetic changes occurring in sugarcane tissues 

subjected to prolonged in vitro culture. This work has demonstrated the scope of selecting improved 

clones of jamrosa with high oil yield and quality through somaclonal variation and suitability of 

RAPDs for detecting gross genetic changes in somaclonal variants at DNA level. 

1.4.2 siM P l e se q u e n C e re P e at Ma r k e r s (ssrs) 

Kumar and coworkers (2007) developed a set of simple sequence repeat markers from a genomic 

library of Cymbopogon jwarancusa to help in the precise identification of the species (including 

accessions) of Cymbopogon. For this purpose, they isolated 16 simple sequence repeats 

containing genomic deoxyribonucleic acid clones of C. jwarancusa, which contained a total of 

32 simple sequence repeats with a range of 1 to 3 simple sequence repeats per clone. The majority 

(68.8%) of the 32 simple sequence repeats comprised dinucleotide repeat motifs followed 

by simple sequence repeats with trinucleotide (21.8%) and other higher-order repeat motifs. 

Eighteen (81.8%) of the 22 designed primers for the above simple sequence repeats amplified 

products of expected sizes, when tried with genomic DNA of C. jwarancusa. Thirteen (72.2%) 

of the 18 functional primers detected polymorphism among the three species of Cymbopogon 

(C. flexuosus, C. pendulus, and C. jwarancusa) and amplified a total of 95 alleles (range 1–18 

alleles) with a PIC value of 0.44 to 0.96 per simple sequence repeat. Thus, the higher allelic 

range and high level of polymorphism demonstrated by the developed simple sequence repeat 

markers are likely to have many applications such as in improvement of essential oil quality by 

authentication of Cymbopogon species and varieties, and mapping or tagging the genes controlling 

agronomically important traits of essential oils, which can further be utilized in marker 

assisted breeding (Kumar et al. 2007). Considering the high reproducibility and polymorphic 

nature of the SSRs, the SSRs developed by Kumar and coworkers (2007) may be utilized for 

identification/authentication of superior accessions/species of the genus Cymbopogon with correctness 

and certainty to ensure production of high-quality oil. The SSR markers developed 

during this kind of study might also be used to resolve the taxonomic disputes, study the genetic 

diversity, and for genetic mapping and QTL (quantitative trait loci) analysis. The SSRs due to 

their codominant nature may be specifically useful for the identification of interspecific hybrids, 

which have been shown to be superior in terms of both their yielding high quantity and better 

quality of essential oils.


1.5 PhysIology and ecoPhysIology 

As discussed, Cymbopogon has a photosynthetic machinery that allows the plant to perform high 

rates of carbon assimilation and, at the same time, save water. In species that produce essential oil, 

the biogenesis of terpenoids relies on photosynthetic carbon dioxide reduction on the one hand and 

availability of water and nutrients, on the other. For this reason several studies have been conducted 

in order to assess which nutrients and at what conditions were required for an optimal production 

of both biomass and essential oils. In this section, we will discuss the most important Cymbopogon 

species in terms of yield of biomass and essential oil production as related to nutrition. Furthermore, 

when available, references to biotechnological applications will be also reported. 

1.5.1 Cy m b o p o g o n martinii 

Water requirement, productivity, and water use efficiency of palmarosa (C. martinii) were studied 

under different levels of irrigation (0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.5 IW:CPE ratio). Growth, 

herb, and essential oil yield increased significantly up to 0.5 IW:CPE ratio. At 0.5 IW:CPE ratio 

palmarosa produced 47.3 t ha −1 yr −1 of fresh herb and 227.3 kg ha −1 yr −1 of essential oil. Further 

increase in irrigation levels caused an adverse effect on growth and yield of palmarosa. Irrigation 

levels did not affect the quality of oil in terms of its geraniol and geranyl acetate contents. Water 

requirement of palmarosa was worked out to be 89.1 cm. The highest water use efficiency of 2.97 kg 

ha −1 cm −1 oil was recorded at 0.1 IW:CPE ratio, at 0.5 IW:CPE ratio (optimum) it was 2.55 kg ha −1 

cm −1 oil. Irrigation scheduled at 0.5 IW:CPE ratio gave the highest net return of Rs 51 963 ha −1 

yr −1 (Singh et al. 1997). In C. martinii the application of 160 kg N/ha per year produced the highest 

amount of biomass and essential oil, and increased the net profit and NPK uptake by the crop 

(Rao et al. 1988); furthermore, dressing of 40 kg K/ha enhanced the yield of biomass by 13.6% and 

6.5% and that of oil by 12.9% and 6.1%, compared with 20 and 80 kg K/ha, respectively (Singh 

et al. 1992). In the same species, harvesting the crop at early seeding (112−115 days after planting) 

gave 25% more herbage and 51% more oil yield over harvesting vegetative stage, while the oil so 

produced had higher content (90.1%) geraniol (Maheshwari et al. 1992). Highest dry-matter yield, 

essential oil yield, and maximum net return of palmarosa were recorded by applying Azotobacter 

at 2 kg/ha together with 20 kg N + 20 kg P/ha under rainfed condition in a shallow black soil 

(Maheshwari et al. 1998). Intercropping of blackgram−blackgram or sorghum fodder−ratoon with 

palmarosa gave additional yields of 660 kg/ha seed and 16.6 t/ha fodder, respectively, compared 

with the sole crop of palmarosa (Rao et al. 1994). Moreover, sowing of pigeon pea in alternate rows 

parallel to palmarosa proved most efficient and economic, as it provided higher economic returns, 

bonus income, and monetary advantage, and the oil content and quality in terms of total geraniols 

of palmarosa were not adversely affected by adoption of intercropping (Maheshwari et al. 1995). 

However, in palmarosa–pigeon pea intercropping systems, competition exists mainly for light rather 

than for nutrients and moisture, possibly because the two crop components acquire their nutrients 

and moisture from different soil layers (Singh et al. 1998). Concerning essential oil production of 

palmarosa, changes in fresh weight, dry weight, chlorophyll, and essential oil content and its major 

constituents, such as geraniol and geranyl acetate, were examined for both racemes and spathe at 

various stages of spikelet development (Dubey et al. 2000). The essential oil content was maximal 

at the unopened spikelets stage and decreased significantly thereafter. At unopened spikelets stage, 

the proportion of geranyl acetate (58.6%) in the raceme oil was relatively greater compared with 

geraniol (37.2%), whereas the spathe oil contained more geraniol (61.9%) compared with geranyl 

acetate (33.4%). The relative percentage of geranyl acetate in both the oils, however, decreased significantly 

with development, and this is accompanied by a corresponding increase in the percentage 

of geraniol. Analysis of the volatile constituents from racemes and spathes (from mature spikelets) 

and seeds by capillary GC indicated 28 minor constituents besides the major constituent geraniol. 

(E)-Nerolidol was detected for the first time in an essential oil from this species. The geraniol


content predominated in the seed oil, whereas the geranyl acetate content was higher in the raceme 

oil (Dubey et al. 2000). 

Biotechnology is a powerful and consolidated technique for understanding plant growth and 

development as well as for improving biomass and yield of crops. Callus could be induced from 

nodal explant of mature tillering plant of C. martinii in different basal media supplemented with 

2,4-dichlorophenoxy acetic acid (2,4-D) and kinetin (Kin). Shoot bud was regenerated from such 

calli in MS and B5 basal media modified with various combinations of phytohormones, vitamins, 

and amino acids. Root formation was induced either in white basal medium or half-strength MS or 

B5 media containing naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA). High survival 

percentage of regenerated plants in soil was obtained after acclimatization in normal environment 

(Baruah and Bordoloi 1991). A detailed characterization of chromosomal status was carried out in 

callus, somatic embryos, and regenerants derived from in vitro cultured nodal and inflorescence 

explants of C. martinii (2n = 20). Both the callus lines revealed considerable ploidy variations (tetraploids 

to octoploids and hyperoctoploids), and the degree of polyploidization increased with the 

culture age. Frequencies of various polyploid cells were significantly higher in nodal callus lines 

(3.6% to 46.3%) than the inflorescence callus lines (1.9% to 23.6%) when analyzed over 520 days 

of culture. Somatic embryos derived from both the callus lines retained a predominantly diploid 

chromosome status throughout (99.0% to 93.1%). Root tip analysis of about 70 regenerants randomly 

taken from cultures of various ages (days 20 to 520) revealed only diploid chromosome 

numbers (2n = 20) implying a strong relative stability of diploidy among the regenerants (Patnaik 

et al. 1996). Chromosome counts of cells in suspensions, calli, and somatic embryos derived from 

cultures of different ages revealed the presence of diploids, tetraploids, and octaploids (Patnaik 

et al. 1997). Sodium chloride tolerant callus lines of C. martinii were obtained by exposing the callus 

to increasing concentrations of NaCl (0–350 mM) in the MS medium. The tolerant lines grew 

better than the sensitive wild-type lines in all concentrations of NaCl tested up to 300 mM. Callus 

survival and growth were completely inhibited, resulting in tissue browning and subsequent death 

at 350 mM NaCl. The selected lines retained their salt tolerance after 3–4 subcultures on salt-free 

medium, indicating the stability of the induced salt tolerance. The growth behavior, the Na + , K + , 

and proline contents of the selected callus lines were characterized and compared with those of 

the NaCl-sensitive lines. The Na + levels increased sharply, while the K + level declined continuously 

with the corresponding increase in external NaCl concentrations in both lines, but the NaCltolerant 

callus lines always maintained higher Na + and K + levels than that of the sensitive lines. 

The NaCl-selected callus line accumulated high levels of proline under salt stress. The degree of 

NaCl tolerance of the selected lines was in negative correlation with the K + /Na + ratio and in positive 

correlation with proline accumulation (Patnaik and Debata 1997a). The embryogenic potential of 

NaCl-tolerant callus selected even at 300 mM could be improved significantly by the incorporation 

of gibberellic acid (GA (3)) and abscisic acid (ABA), in the medium where, with 2 mg/L of GA (3) 

and 1 mg/L of ABA, the highest rates of embryogenesis (44.5%, 28.8%, and 18.6%) were achieved 

against 17.5%, 8.2%, and 1.8% on medium devoid of GA (3), and ABA at 50%, 150%, and 250 mM 

of NaCl, respectively (Patnaik and Debata 1997b). Finally, plants regenerated from cell suspension 

cultures of palmarosa were analyzed for somaclonal variation in five clonal generations. A wide 

range of variation in important quantitative traits, for example, plant yield, height, tiller number, 

oil content and qualitative changes in essential oil constituents geraniol, geranyl acetate, geranyl 

formate, and linalool, were observed among the 120 somaclones screened. Eight somaclones were 

selected on the basis of high herb and oil yield over the donor line and high geraniol content in the 

oil. Based on performance in the field trials, three superior lines were selected, and maintained for 

five clonal generations. The superior lines exhibited a reasonable degree of stability in the traits 

selected (Patnaik et al. 1999). 

Palmarosa was also found to be associated with a vesicular-arbuscular mycorrhizal (VAM) 

fungus, Glomus aggregatum. Glasshouse experiments showed that inoculation of palmarosa with 

G. aggregatum caused a twofold and threefold biomass production as compared to nonmycorrhizal


plants. These findings indicate the potential use of VAM-fungi for improving the production of this 

essential oil-bearing plant (Gupta and Janardhanan 1991). Furthermore, when the interactive effects 

of phosphate solubilizing bacteria, N-2 or fixing bacteria, and arbuscular mycorrhizal fungi (AMF) 

were studied in a low phosphate alkaline soil amended with a tricalcium insoluble source of inorganic 

phosphate on the growth of C. martinii. The rhizobacteria behaved as a “mycorrhiza helper” 

and enhanced root colonization by G. aggregatum in presence of tricalcium phosphate at the rate of 

200 mg kg −1 soil (P1 level) (Ratti et al. 2001). 

A dramatic increase in PEP carboxylase activity and oil biosynthesis was observed under 

drought conditions in C. martinii (Sangwan et al. 1993). The physiological and biochemical 

basis of drought tolerance in C. martinii has been elucidated on the basis of growth and metabolic 

responses (Fatima et al. 2002). 

1.5.2 Cy m b o p o g o n f l e x u o s u s 

Cymbopogon flexuosus (also known as lemongrass) is a perennial, multicut aromatic grass that 

yields an essential oil used in perfumery and pharmaceutical industries and vitamin A. It has a 

long initial lag phase. The growth and herbage and oil production of C. flexuosus in response to 

different levels of irrigation water (IW) 0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.5 times cumulative pan 

evaporation CPE evaluated on deep sandy soils showed that an increment in the level of irrigation 

increased the plant height up to 0.7 IW:CPE ratio. However, the response of irrigation levels 

on tiller pro duction of lemongrass differed with the season of harvest. Oil content had an inverse 

relationship with the levels of irrigation, whereas significantly higher herb and essential oil yields 

were recorded at 0.7 IW:CPE ratio, irrespective of season of harvest (Singh et al. 2000). Application 

of nitrogen (0, 50, 100, and 150 kg N ha −1 yr −1 ) and phosphorus to C. flexuosus crops maintained 

the fertility of the soil, while potassium depletion was noticed (Singh 2001). When the effects of 

phosphorus (at 0, 17.75, and 35.50 kg ha −1 yr −1 ), potassium (at 0, 33.2, 66.4, and 99.6 kg ha −1 yr −1 ) and 

nitrogen (at 100 and 200 kg ha −1 yr −1 ) and potassium (at 0, 33.2 and 66.4 kg ha −1 yr −1 ) were studied 

on herbage and oil yield of C. flexuosus, it was found that plants produced significantly higher herbage 

and oil yields compared with controls (Singh et al. 2005; Singh and Shivaraj 1999). Spraying of 

iron-complexed additives on C. flexuosus increased iron translocation and the dry-matter production. 

Application of iron chelates and salts increased the vegetative herb yield, and oil and citral 

content. While maximum geraniol and less citral were obtained in the chlorotic plants, Fe recovered 

plants possessed more citral and less geraniol. The maximum recovery of total chlorophyll 

and nitrate reductase activity were recorded in the crop when Fe-EDTA chelates were sprayed at 

22.4 ppm (Misra and Khan 1992). In C. flexuosus, a closer plant spacing of 45 × 45 cm resulted in 

higher herb and oil yields compared to wider spacing of 60 × 60 cm. Application of 150 kg N ha −1 

yr −1 resulted in higher herb and oil yields. Higher nitrogen applications also increased the plant 

height and number of tillers per clump. The oil content and quality were not influenced by spacing 

and nitrogen levels (Singh et al. 1996b). 

As for C. martinii, intercropping of C. flexuosus with the food legumes such as blackgram 

(Vigna mungo (L) Hepper), cowpea (Vigna unguiculata (L) Walp), or soybean (Glycine max (L) 

Merr.) prompted extra yields over and above that of pure cultures, without affecting the oil yield 

(Singh and Shivaraj 1998). 

The influence of different foliar applications of the triacontanol (Tria.)-based plant growth regulator 

Miraculan on growth, CO 2 exchange, and essential oil accumulation in C. flexuosus showed 

increased rates in plant height, tillers per plant, biomass yield, accumulation of essential oil, net 

CO 2, and exchange and transpiration compared to the untreated control, but the number of leaves per 

tiller remained unaffected. Application of Miraculan also increased micronutrient uptake and total 

chlorophyll and citral content but decreased chlorophyll a/b ratio and stomatal resistance. Increase 

in shoot biomass, photosynthesis, and chlorophyll were significantly correlated with essential oil 

content (Misra and Srivastava 1991). Only young and rapidly expanding C. flexuosus leaves were


found to have the capacity to synthesize and accumulate essential oil and citral. The pattern of the 

ratio of the label incorporated in citral to that in geraniol, during leaf ontogeny, evinced parallelism 

with the geraniol dehydrogenase activity. The elevated levels of glucose-6-phosphate dehydrogenase, 

6-phosphogluconate dehydrogenase, NADP + -malic enzyme, and NADP + -isocitrate dehydrogenase 

coincided with the period of active essential oil biogenesis accompanying early leaf growth (Singh 

et al. 1990). Thus, there is an active involvement of oxidative pathways in essential oil biosynthesis. 

The time-course (12 h light followed by 12 h dark) monitoring of the C-14 radioactivity in starch and 

essential oil, after exposure of the immature (15 days after emergence) leaf to (CO)-C-14, revealed 

a progressive loss of label from starch and a parallel increase in radioactivity in essential oil. Thus, 

there was indication of a possible degradation of transitory starch serving as the source of carbon 

precursor for essential oil (monoterpene) biogenesis in the tissue (Singh et al. 1991). 

Biotechnological applications revealed that C. flexuosus plants derived from somatic embryoids 

were more uniform in all the characteristics examined when compared with the field performance 

of plants raised through slips by standard propagation procedures (Nayak et al. 1996). 

A fungal endophyte, Balansia sclerotica (Pat.) Hohn., has been found to establish a perennial 

association with the commercially grown East Indian C. flexuosus cv. Kerala local (syn. = OD-19). 

Endophyte-infected plants produced 195% more shoot biomass and 185% more essential oil than 

the endophyte-free control plants when grown experimentally under glasshouse conditions. The 

essential oil extracted from the endophyte-infected plants is qualitatively identical with that of 

endophyte-free plants and is free of toxic ergot alkaloids. Thus, B. sclerotica-infected East Indian 

C. flexuosus has potential for agricultural exploitation (Ahmad et al. 2001). 

1.5.3 Cy m b o p o g o n w i n t e r i a n u s 

Java citronella (C. winterianus) is a perennial, multiharvest aromatic grass, the shoot biomass of 

which, on steam distillation, yields an essential oil extensively used in fragrance and flavor industries. 

Fresh C. winterianus (Java citronella) herbage and essential oil yields were significantly influenced 

by application of N up to 200 kg ha −1 yr −1 , while tissue N concentration and N uptake increased only 

to 150 kg N ha −1 . The oil yields with neem cake-coated urea (urea granules coated with neem cake) 

and urea super granules were 22 and 9% higher over that with prilled urea, and urea supergranules 

were significantly increased up to 200 kg N ha −1 while with neem cake-coated urea, response was 

observed only to 150 kg N ha −1 ! Estimated recovery of N during two years from neem cake-coated 

urea, urea supergranules, and prilled urea were 38%, 31%, and 21%, respectively (Singh and Singh 

1992). The interaction between N doses and nitrification inhibitors was also significant. Nitrification 

inhibitors performed better at the highest N dose (450 kg N ha −1 yr −1 ), and the increase in the essential 

oil yields was to an extent of 27.3% to 34.6% when compared with “N alone” treatment. The 

nitrification inhibitors also increased the apparent N recoveries by citronella considerably. The oil 

content in the herb and its quality were not affected by the treatments. The nitrification inhibitors 

increased citronella yields and improved N economy (Puttanna et al. 2001). In Java citronella significant 

positive correlations were observed between fresh matter, citronellol content, dry and fresh 

matter yields, and total essential oil content (Omisra and Srivastava 1994). When the effect of depth 

(25, 37.5, and 50 mm) and methods (ridge and furrow, and broad bed and furrow method) of irrigation 

acid nitrogen levels (0, 200, and 400 kg N ha −1 yr −1 ) were studied on herb and oil yields of Java 

citronella, highest herb and oil yields were achieved with the application of 400 kg N, maintaining 

25 mm depth of irrigation, while the content and quality of oil were not affected either by irrigation 

or nitrogen (Singh et al. 1996a). 

Among food legumes, greengram (Vigna radiata (L.) Wilez.), and among vegetables, clusterbean 

(Cyamopsis psoraloides D. C., syn. Cyamopsis tetragonoloba (L.) Taub.), tomato (Lycopersicon 

esculentum Mill.) and lady’s finger (Abelmoschus esculentus Moench.) as intercrops of C. winterianus 

did not decrease its biomass and essential oil yield and produced bonus yields of these 

crops over and above that of Java citronella. Maximum monetary returns were recorded by Java


citronella intercropped with tomato or greengram. However, Java citronella intercropped with redgram 

(Cajanus cajan (L.) Millsp.), horsegram (Macrotyloma uniflorum (Lam.) Verd, syn. Dolichos 

biflorus Roxb.), and brinjal (Solanum melongena L.) suffered significant biomass and essential oil 

yield reductions. Horsegram proved to be the most competitive intercrop, producing least yields and 

minimum monetary returns (Rao 2000). 

Changes in the utilization pattern of primary substrate, viz. [U-C-14] acetate, (CO 2)-C-14 

and [U-C-14] saccharose, and the contents of C-14 fixation products in photosynthetic metabolites 

(sugars, amino acids, and organic acids) were determined in Fe-deficient Java citronella in 

relation to the essential oil accumulation. An overall decrease in photosynthetic efficiency of the 

Fe-deficient plants as evidenced by lower levels of incorporation into the sugar fraction and essential 

oil after (CO 2)-C-14 had been supplied was observed. When acetate and saccharose were fed 

to the Fe-deficient plants, despite a higher incorporation of label into sugars, amino acids, and 

organic acids, there was a lower incorporation of these metabolites into essential oils than in control 

plants. Thus, the availability of precursors and the translocation to a site of synthesis/accumulation, 

severely affected by Fe deficiency, is equally important for the essential oil biosynthesis in citronella 

(Srivastava et al. 1998). Lal and coworkers (2001) observed that improvement of oil quality 

with high citronellal content and low elemol content in Java citronella is believed to be achievable, 

although some compromise will have to be made in oil yield. 

Nutrient acquisition and growth of Java citronella was also studied in a P-deficient sandy soil 

to determine the effects of mycorrhizal symbiosis and soil compaction. When a pasteurized sandy 

loam soil was inoculated either with rhizosphere microorganisms excluding VAM fungi (nonmycorrhizal) 

or with the VAM fungus, Glomus intraradices Schenck and Smith (mycorrhizal) and supplied 

with 0, 50, or 100 mg P kg −1 soil, G. intraradices was found to substantially increase root and 

shoot biomass, root length, nutrient (P, Zn, and Cu) uptake per unit root length, and nutrient concentrations 

in the plant, compared to inoculation with rhizosphere microorganisms when the soil was at 

the low bulk density and not amended with P. Little or no plant response to the VAM fungus was 

observed when the soil was supplied with 50 or 100 mg P kg −1 soil and/or compacted to the highest 

bulk density. At higher soil compaction and P supply, the VAM fungus significantly reduced root 

length. Nonmycorrhizal plants at higher soil compaction produced relatively thinner roots and had 

higher concentrations and uptake of P, Zn, and Cu than at lower soil compaction, particularly under 

conditions of P deficiency (Kothari and Singh 1996). 

Pythium aphanidermatum was the predominant fungus recovered from the roots of Java citronella 

showing lethal yellowing in the northern part of India. Roots of infected plants showed marked 

discoloration, and the cortical region was completely disintegrated and sloughed from the vascular 

tissue. Diseased plants were chlorotic and stunted. Rotting was often found to spread from roots to 

stem, leading to severe chlorosis and death of the infected plants. The pathogenicity of the fungus 

was established. The disease is a potential constraint to citronella cultivation in nonarid climates 

where the crop is irrigated extensively (Alam et al. 1992). Another disease affecting commercial 

plantations of Java citronella is a collar rot and wilt disease. The causal organism was identified as 

Fusarium moniliforme, anamorph of Gibberella fujikuroi. Isolates of the pathogen differed in their 

pathogenicity on the host plant under glasshouse conditions. Differences were also observed in 

growth rates, pigment production, and sporulation between isolates (Alam et al. 1994). 

1.5.4 ot h e r Cy m b o p o g o n sP e C i e s 

Application of graded levels of lime up to 10 t/ha on acid soil (pH 4.2) raised the pH up to 6.7. It 

increased the dry herbage of C. khasianus linearly. Increase of soil pH decreased N, P, K, Fe, and 

Zn contents in dry herbage significantly but increased the Ca and Mg contents. Liming showed a 

positive effect on the uptake of N, P, K, and Ca. However, Fe and Mg declined beyond lime levels 

of 23 and 5.0 t, respectively. Uptake of Zn was found fluctuating. Oil content (2.00%–2.07%; DWB) 

and geraniol (80.2%–81.0%) in the oil were unaffected by the lime treatments (Choudhury and


Bordoloi 1992). Experiments were also conducted to measure the rate of C. caesius litter decomposition 

and to identify fungal flora associated with the litter during different stages of decomposition 

in a tropical grassland. Rate of litter decomposition was several times higher than in temperate 

grasslands. Buried litter decayed more rapidly, and this rate was not influenced by climatic conditions. 

In contrast, surface litter recorded a lower decomposition rate, which was dependent on temporal 

(seasonal) fluctuations. Total nitrogen, available phosphorus, and potassium contents of the 

stem litter decreased during the initial stages of incubation. 

Thirty-five species of fungi were isolated from the litter during the different stages of litter 

degradation. Most belonged to Hyphomycetes, which are active decomposers (Senthilkumar et al. 

1992). C. nardus var. confertiflorus and C. pendulus were grown under mild and moderate water 

stress for 45 and 90 d to investigate the impact of in situ drought stress on plants in terms of relative 

water content, psi, concentration of proline, activities of PEP carboxylase and geraniol dehydrogenase, 

and geraniol and citral biogenesis. The results revealed that the species exhibited differential 

responses under mild and moderate stress treatments. In general, plant growth was reduced considerably, 

while the level of essential oils was maintained or enhanced. 

Significant induction in catalytic activity of PEP carboxylase under water stress was one of the 

consistent metabolic responses of the aromatic grasses. The major oil constituents, geraniol and 

citral, increased substantially in both the species. Activity of geraniol dehydrogenase was also 

modulated under moisture stress. The responses varied depending upon the level and duration of 

moisture stress. The observations have been analyzed in terms of possible relevance of some of 

these responses to their drought stress adaptability/tolerance (Singhsangwan et al. 1994). In vitro 

plants of C. citratus were established, starting from shoot apices derived from plants cultivated 

under field conditions. The effect of the immersion frequency (two, four, and six immersions per 

day) on the production of biomass in temporary immersion systems (TIS) of 1 L capacity was studied. 

The highest multiplication coefficient (12.3) was obtained when six immersions per day were 

used. The maximum values of fresh weight (FW; 62.2 and 66.2 g) were obtained with a frequency 

of four and six immersions per day, respectively. However, the values for dry weight (DW; 6.4 g) 

and height (8.97 cm) were greater in the treatment with four immersions per day. The TIS used in 

this work for the production of lemongrass biomass may offer the possibility of manipulating the 

culture parameters, which can influence the production of biomass and the accumulation of secondary 

metabolites. We describe for the first time the in vitro production of Cymbopogon citratus 

biomass in TIS. In vitro regeneration of C. polyneuros was obtained through callus culture using 

leaf base, node, and root as explants. Callus was induced from different explants with 2–5 mg/L 

alpha-naphthalene acetic acid (NAA) and 1–2 mg/L kinetin in Murashige and Skoog’s (MS) basal 

medium. High frequency shoots were noticed from leaf-base callus supplemented with 3.5 mg/L 

6-benzylaminopurine (BA), l-arginine, adenine, and a low level of NAA (0.2 mg/L). About 80–85 

shoot buds were obtained from ca. 200 mg of callus per culture. The individual shoots produced 

root in the presence of 0.5–3 mg/L indole 3-butyric acid or its potassium salt. 

Regenerated plants were cytologically and phenotypically stable. Regenerants were transplanted 

into soil and subsequently transferred to the field (Das 1999). C. nardus could be propagated via 

tissue culture using axillary buds as explants. The aseptic bud explants obtained using double sterilization 

methods produced stunted abnormal multiple shoots when they were cultured on Murashige 

and Skoog (MS) medium supplemented with 1.0 mg L −1 or 2.0 mg L −1 benzyladenine (BA). Stunted 

shoots that cultured on MS + 1.0 mg L −1 RA + 1.0 mg L −1 N-6-isopentenyl-adenine (2iP) could 

induce elongation of shoots from about 60% of the stunted shoots. Normal multiple shoots could 

be induced at the highest (19.7 shoots per bud) from the bud explants within 6 weeks when cultured 

on proliferation medium consisted of MS supplemented with 0.3 mg L −1 BA and 0.1 mg L −1 

indole-3-butyric acid (IBA). The separated individual shoot produced roots when transferred to 

basic MS solid medium. The essential oils that were contained in the mature plants namely citronellal, 

geraniol, and citronellol, were also found in the in vitro C. nardus plantlets. Citronellal was 

the main essential oil component in the matured plants, while geraniol was the main component in


the in vitro plantlets (Chan et al. 2005). The occurrence, mode of infection, and the extent of damage 

caused by Psilocybe kashmeriensis sp. nov. Abraham on oil grass C. jawarancusa in Kashmir 

valley is discussed herein. A brief description of the new agaric species is also offered (Abraham 

1995). Dormant vegetative slips of jamrosa (C. nardus var. confertiflorus × C. jwarancusa) were 

subjected to various doses of gamma rays. Plants raised from them were screened with a view to isolate 

improved clones of the crop. Five mutant clones isolated exhibited variation in quality/ quantity 

of essential oil. These changes in oil characters were attributed to microlevel mutations induced by 

gamma rays (Kak et al. 2000). 

reFerences 

Abraham SP. 1995. Notes on the occurrence of an unusual agaric on Cymbopogon in Kashmir Valley. Nova 

Hedwigia 60: 227–232. 

Adams RP, Dafforn MR. 1997. DNA sampling of the pan-tropical vetiver grass uncovers genetic uniformity in 

erosion control germplasm. Diversity 13: 27, 28. 

Ahmad A, Alam M, Janardhanan KK. 2001. Fungal endophyte enhances biomass production and essential oil 

yield of East Indian lemongrass. Symbiosis 30: 275–285. 

Al-Zahim MA, Ford-Lloyd BV, Newbury HJ. 1999. Detection of somaclonal variation in garlic (Allium sativum 

L.) using RAPD and cytological analysis. Plant Cell Reports 18: 473–477. 

Alam M, Chourasia HK, Sattar A, Janardhanan KK. 1994. Collar rot and wilt—a new disease of Java-citronella 

(Cymbopogon winterianus) caused by Fusarium-moniliforme sheldon. Plant Pathology 43: 1057–1061. 

Alam M, Sattar A, Janardhanan KK, Husain A. 1992. Lethal yellowing of Java citronella (Cymbopogon winterianus) 

caused by Pythium aphanidermatum. Plant Disease 76: 1074–1076. 

Ashton AR. 1990. Enzymes of C 4 photosynthesis. In Dey PMHJB, Ed. Methods in Plant Biochemistry. London: 

Academic Press, pp. 39–72. 

Baruah A, Bordoloi DN. 1991. Growth and regeneration of palmarosa (Cymbopogon martinii [Roxb.] Wats.) 

callus tissues under varied nutritional status. Indian Journal of Experimental Biology 29: 582, 583. 

Bertea CM, Scannerini S, D’Agostino G, Mucciarelli M, Camusso W, Bossi S, Buffa G, Maffei M. 2001. Evidence 

for a C4 NADP-ME photosynthetic pathway in Vetiveria zizanioides Stapf. Plant Biosystems 135: 249–262. 

Bertea CM, Tesio M, D’Agostino G, Buffa G, Camusso W, Bossi S, Mucciarelli M, Scannerini S, Maffei M. 

2003. The C–4 biochemical pathway, and the anatomy of lemongrass (Cymbopogon citratus (DC) Stapf.) 

cultivated in temperate climates. Plant Biosystems 137: 175–184. 

Breakwell E. 1914. A study of the leaf anatomy of some native species of the genus Andropogon, N.O. 

Gramineae. Proceedings of the Linnean Society, N.S.W. 39: 385–394. 

Casati P, Spampinato CP, Andreo CS. 1997. Characteristics and physiological function of NADP-malic enzyme 

from wheat. Plant Cell Physiology 38: 928–934. 

Chalmers KJ, Waugh R, Simons AJ, Powell W. 1992. Detection of genetic variations between and within populations 

of Gliricidia sepium and G. maculata using RAPD markers. Heredity 69: 465–472. 

Chan LK, Dewi PR, Boey PL. 2005. Effect of plant growth regulators on regeneration of plantlets from bud 

cultures of Cymbopogon nardus L. and the detection of essential oils from the in vitro plantlets. Journal 

of Plant Biology 48: 142–146. 

Chapman KSR, Hatch MD. 1983. Intracellular location of phosphoenolpyruvate carboxykinase and other 

C 4 photosynthetic enzymes in mesophyll and bundle sheath protoplasts of Panicum maxymum. Plant 

Science Letters 29: 145–154. 

Choudhury SN, Bordoloi DN. 1992. Effect of liming on the uptake of nutrients and yield performance of 

Cymbopogon khasianus in acid soils of Northeast India. Indian Journal of Agronomy 37: 518–522. 

Das AB. 1999. Effects of different physiochemical factors on regeneration of Cymbopogon polyneuros Stapf. 

via callus culture and subsequent chromosomal stability. Israel Journal of Plant Sciences 47: 195–198. 

Dengler NG, Nelson T. 1999. Leaf structure and development in C4 plants. In Sage RF, Monson RK, Eds. The 

Biology of C4 Plants. San Diego: Academic Press, pp. 133–172. 

Dubey VS, Mallavarapu GR, Luthra R. 2000. Changes in the essential oil content and its composition during 

palmarosa (Cymbopogon martinii (Roxb.) Wats. var. motia) inflorescence development. Flavour and 

Fragrance Journal 15: 309–314. 

Eastman PAK, Dengler NG, Peterson CA. 1988. Suberized bundle sheaths in grasses (Poaceae) of different 

photosynthetic types I. Anatomy, ultrastructure, and histochemistry. Protoplasma 142: 92–111. 

Edwards GE, Andreo CS. 1992. NADP-Malic enzyme from plants. Phytochemistry 31: 1845–1857.


Edwards GE, Walker OA. 1983. C3, C4: Mechanism, and Cellular and Environmental Regulation of 

Photosynthesis. London: Blackwell Scientific Publications. 

Fatima S, Farooqi AHA, Sharma S. 2002. Physiological and metabolic responses of different genotypes of 

Cymbopogon martinii and C. winterianus to water stress. Plant Growth Regulation 37: 143–149. 

Fitter AH, Hay RKM. 1987. Environmental Physiology of Plants. London: Academic Press. 

Ghannoum O, van Caemmerer S, Conroy JP. 2001. Carbon and water economy of Australian NAD-ME and 

NADP-ME C4 grasses. Australian Journal of Plant Physiology 28: 213–223. 

Guenther E. 1950a. The Essential Oils (IV). New York, Van Nostrand. Ref Type: Serial (Book, Monograph). 

Guenther E. 1950b. The Essential Oils. Princeton: Van Nostrand. 

Gupta ML, Janardhanan KK. 1991. Mycorrhizal association of Glomus aggregatum with palmarosa enhances 

growth and biomass. Plant and Soil 131: 261–263. 

Gutierrez M, Gracen VE, Edwards GE. 1974. Biochemical and cytological relationships in C 4 plants. Planta 

119: 279–300. 

Hatch MD. 1988. C 4 photosynthesis: A unique blend of modified biochemistry, anatomy and ultrastructure. 

Biochimica et Biophysica Acta 895: 81–106. 

Hatch MD. 1992. C 4 photosynthesis: An unlikely process full of surprises. Plant and Cell Physiology 33: 

333–342. 

Hatch MD, Kagawa T, Craig S. 1975. Subdivision of C 4-pathway species based on differing C 4 acid decarboxylating 

systems and ultrastructural features. Australian Journal of Plant Physiology 2: 111–128. 

Hatch MD, Kagawa T, Craig S. 2007. Subdivision of C 4-pathway species based on differing C 4 acid decarboxylating 

systems and ultrastructural features. Australian Journal of Plant Physiology 2: 111–128. 

Hattersley PW, Watson L. 1976. C 4 grasses: An anatomical criterion for distinguishing between NADP-malic 

enzyme species and PCK or NAD-malic enzyme species. Australian Journal of Botany 24: 297–308. 

Huang Y, Street-Perrot FA, Metcalfe SE, Brenner M, Moreland M, Freeman KH. 2001. Climate change as the dominant 

control on glacial–interglacial variations in C3 and C4 plant abundance. Science 293: 1647–1651. 

Jain N, Shasany AK, Sundaresan V, Rajkumar S, Darokar MP, Bagchi GD, Gupta AK, Kumar S, Khanuja SPS. 

2003. Molecular diversity in Phyllanthus amarus assessed through RAPD analysis. Current Science 85: 

1454–1458. 

Jenkins CLD, Furbank RT, Hatch MD. 1989. Mechanism of C 4 photosynthesis. Plant Physiology 91: 

1372–1381. 

Kak SN, Bhan MK, Rekha K. 2000. Development of improved clones of jamrosa (Cymbopogon nardus [L.] 

Rendle var. confertiflorus [Steud.] Bor. x C. jwarancusa Jones Schult.) through induced mutations. 

Journal of Essential Oil Research 12: 108–110. 

Khanuja SPS, Shasany AK, Pawar A, Lal RK, Darokar MP, Naqvi AA, Rajkumar S, Sundaresan V, Lal N, Kumar 

S. 2005. Essential oil constituents and RAPD markers to establish species relationship in Cymbopogon 

Spreng. (Poaceae). Biochemical Systematics and Ecology 33: 171–186. 

Kothari SK, Singh UB. 1996. Response of Java citronella (Cymbopogon winterianus Jowitt) to VA mycorrhizal 

fungi and soil compaction in relation to P supply. Plant and Soil 178: 231–237. 

Kresovich S, Lamboy RL, Li R, Szewc-McFadden AK, Blick SM. 1994. Application of molecular methods 

and statistical analysis for discrimination of accessions and clones of vetiver grass. Crop Science 34: 

805–809. 

Kumar J, Verma V, Shahi AK, Qazi GN, Balyan HS. 2007. Development of simple sequence repeat markers in 

Cymbopogon species. Planta Medica 73: 262–266. 

Kumar S, Dwivedi S, Kukreja AK, Sharma JR, Bagchi GD. 2000. Cymbopogon: The Aromatic Grass. Lucknow, 

India: Central Institute of Medicinal and Aromatic Plants. 

Kuriakose KP. 1995. Genetic variability in East Indian lemongrass (Cymbopogon flexuosus Stapf). Indian 

Perfumer 39: 76–83. 

Lal RK, Sharma JR, Misra HO, Sharma S, Naqvi AA. 2001. Genetic variability and relationship in quantitative 

and qualitative traits of Java citronella (Cymbopogon winterianus Jowitt). Journal of Essential Oil 

Research 13: 158–162. 

Larkin PJ, Scowcroft WR. 1981. Somaclonal variation a novel source of variability from cell cultures for plant 

improvement. Theoretical and Applied Genetics 60: 197–214. 

Leegood RC. 1993. Carbon dioxide-concentrating mechanisms. In Lea PJ, Leegood RC, Eds. Plant Biochemistry 

and Molecular Biology. Chichester, U.K: Wiley & Sons, pp. 47–72. 

Lunn JE, Agostino A, Hatch MD. 1995. Regulation of NADP-malate dehydrogenase in C 4 plants—activity and 

properties of maize thioredoxin M and the significance of non-active site thiol groups. Australian Journal 

of Plant Physiology 55: 577–584. 

Maffei M. 2002. Vetiveria—The Genus Vetiveria. London: Taylor & Francis.


Maffei M, Codignola A, Fieschi M. 1988. Photosynthetic enzyme activities in lemongrass cultivated in temperate 

climates. Biochemical Systematics and Ecology 16: 263, 264. 

Maheshwari SK, Chouhan GS, Trivedi KC, Gangrade SK. 1992. Effect of irrigation and stage of crop harvest 

on oil yield and quality of palmarosa (Cymbopogon martinii) oil grass. Indian Journal of Agronomy 37: 

514–517. 

Maheshwari SK, Sharma RK, Gangrade SK. 1995. Effect of spatial arrangement on performance of palmarosa 

(Cymbopogon martinii var. motia)—pigeonpea (Cajanus cajan) intercropping on a black cotton soil 

(vertisol). Indian Journal of Agronomy 40: 181–185. 

Maheshwari SK, Sharma RK, Gangrade SK. 1998. Response of palmarosa (Cymbopogon martinii var. motia) 

to biofertilizers, nitrogen, and phosphorus in a shallow black soil under rainfed condition. Indian Journal 

of Agronomy 43: 175–178. 

Mathews S, Spangler RE, Mason-Gamer RJ, Kellogg EA. 2002. Phylogeny of Andropogoneae inferred from 

phytochrome B, GBSSI, and NDHF. International Journal of Plant Sciences 163: 441–450. 

Mathur AK, Ahuja PS, Pandey B, Kukreja AK, Mandal S. 1988. Screening and evaluation of somaclonal variations 

for quantitative and qualitative traits in aromatic grass, Cymbopogon winterianus Jowitt. Plant 

Breeding 101: 321–334. 

Maurino VG, Drincovich MF, Casati P, Andreo CS, Edwards GE, Ku MSB, Gupta SK, Franceschi VR. 1997. 

NADP-malic enzyme: Immunolocalization in different tissues of the C 4 plant maize and the C 3 plant 

wheat. Journal of Experimental Botany 48: 799–811. 

Metcalfe CR. 1960. Anatomy of the Monocotyledons. I. Gramineae. London: Oxford University Press. 

Misra A, Khan A. 1992. Correction of iron-deficiency chlorosis in lemongrass (Cymbopogon flexuosus Steud.) 

Watts. Agrochimica 36: 349–360. 

Misra A, Srivastava NK. 1991. Effect of the triacontanol formulation miraculan on photosynthesis, growth, 

nutrient uptake, and essential oil yield of lemongrass (Cymbopogon flexuosus) Steud. Watts. Plant 

Growth Regulation 10: 57–63. 

Munthali MT, Newbury HJ, Ford-Loyd BV. 1996. The detection of somaclonal variants of beet using RAPD. 

Plant Cell Reports 15: 474–478. 

Nayak S, Debata BK, Sahoo S. 1996. Rapid propagation of lemongrass (Cymbopogon flexuosus [Nees] Wats.) 

through somatic embryogenesis in vitro. Plant Cell Reports 15: 367–370. 

Nayak S, Debata BK, Srivastava VK, Sangwan NS. 2003. Evaluation of agronomically useful somaclonal variants 

in jamrosa (a hybrid Cymbopogon) and detection of genetic changes through RAPD. Plant Science 

164: 1029–1035. 

Omisra A, Srivastava NK. 1994. Influence of iron nutrition on chlorophyll contents, photosynthesis, and 

essential monoterpene oil(s) in Java citronella (Cymbopogon winterianus Jowitt). Photosynthetica 30: 

425–434. 

Patnaik J, Debata BK. 1997a. In vitro selection of NaCl tolerant callus lines of Cymbopogon martinii (Roxb.) 

Wats. Plant Science 124: 203–210. 

Patnaik J, Debata BK. 1997b. Regeneration of plantlets from NaCl tolerant callus lines of Cymbopogon martinii 

(Roxb.) Wats. Plant Science 128: 67–74. 

Patnaik J, Sahoo S, Debata BK. 1996. Cytology of callus, somatic embryos and regenerated plants of palmarosa 

grass, Cymbopogon martinii (Roxb.) Wats. Cytobios 87: 79–88. 

Patnaik J, Sahoo S, Debata BK. 1997. Somatic embryogenesis and plantlet regeneration from cell suspension 

cultures of palmarosa grass (Cymbopogon martinii). Plant Cell Reports 16: 430–434. 

Patnaik J, Sahoo S, Debata BK. 1999. Somaclonal variation in cell suspension culture-derived regenerants of 

Cymbopogon martinii (Roxb.) Wats. var. motia. Plant Breeding 118: 351–354. 

Pecchioni N, Faccioli P, Monetti A, Stanca AM, Terzi V. 1996. Molecular markers for genotype identification 

in small grain cereals. Journal of Genetic Breeding 50: 203–219. 

Phillips SM, Hua P. 2005. Notes on grasses (Poaceae) for the flora of China, V. New species in Cymbopogon. 

Novon 15: 471–473. 

Prat H. 1937. Caractères anatomique et histologiques de quelques Andropogonées de l’Afrique occidentale. 

Ann. Mus. Colon. Marseille 5: 25–28. 

Purseglove JW. 1975. Tropical Crops: Monocotyledons. London: Longman Group Ltd. 

Puttanna K, Gowda NMN, Rao EVSP. 2001. Effects of applications of N fertilizers and nitrification inhibitors 

on dry matter and essential oil yields of Java citronella (Cymbopogon winterianus Jowitt.). Journal of 

Agricultural Science 136: 427–431. 

Quiala E, Barbon R, Jimenez E, De Feria M, Chavez M, Capote A, Perez N. 2006. Biomass production of 

Cymbopogon citratus (DC) Stapf., a medicinal plant, in temporary immersion systems. In Vitro Cellular 

and Developmental Biology–Plant 42: 298–300.


Rajendrudu G, Das VSR. 1981. C4 photosynthetic carbon metabolism in the leaves of aromatic tropical 

grasses—I. Leaf anatomy, CO 2 compensation point and CO 2 assimilation. Photosynthesis Research 2: 

225–233. 

Rani V, Parida A, Raina SN. 1995. Random amplified polymorphic DNA (RAPD) micropropagated plants of 

Populus deltoides Marsh. Plant Cell Reports 14: 459–462. 

Rao BRR. 2000. Biomass yield and essential oil yield variations in Java citronella (Cymbopogon winterianus 

Jowitt.), intercropped with food legumes and vegetables. Journal of Agronomy and Crop Science— 

Zeitschrift fur Acker und Pflanzenbau 185: 99–103. 

Rao EVSP, Singh M, Chandrasekhara G. 1988. Effect of nitrogen application on herb yield, nitrogen uptake 

and nitrogen recovery in Java citronella (Cymbopogon Winterianus Jowitt). Indian Journal of Agronomy 

33: 412–415. 

Rao EVSP, Singh M, Rao RSG. 1994. Performance of intercropping systems based on palmarosa (Cymbopogon 

martinii var. motia). Indian Journal of Agricultural Sciences 64: 442–445. 

Ratti N, Kumar S, Verma HN, Gautam SP. 2001. Improvement in bioavailability of tricalcium phosphate to 

Cymbopogon martinii var. motia by rhizobacteria, AMF and Azospirillum inoculation. Microbiological 

Research 156: 145–149. 

Rothermel BA, Nelson T. 1989. Primary structure of the maize NADP-dependent malic enzyme. Journal of 

Biological Chemistry 264: 19587–19592. 

Sangwan NS, Yadav U, Sangwan RS. 2001. Molecular analysis of genetic diversity in elite Indian cultivars of 

essential oil trade types of aromatic grasses (Cymbopogon species). Plant Cell Reports 20: 437–444. 

Sangwan NS, Yadav U, Sangwan RS. 2003. Genetic diversity among elite varieties of the aromatic grasses, 

Cymbopogon martinii. Euphytica 130: 117–130. 

Sangwan RS, Farooqi AHA, Bansal RP, Singhsangwan N. 1993. Interspecific variation in physiological and 

metabolic responses of 5 species of Cymbopogon to water stress. Journal of Plant Physiology 142: 

618–622. 

Sangwan RS, Sangwan NS, Jain DC, Kumar S, Ranade SA. 1999. RAPD profile-based genetic characterization 

of chemotypic variants of Artemisia annua L. Biochemistry and Molecular Biology International 

47: 935–944. 

Senthilkumar K, Udaiyan K, Manian S. 1992. Rate of litter decomposition in a tropical grassland dominated by 

Cymbopogon caesius in Southern India. Tropical Grasslands 26: 235–242. 

Shasany AK, Lal RK, Patra NK, Darokar MP, Garg A, Kumar S, Khanuja SPS. 2000. Phenotypic and RAPD 

diversity among Cymbopogon winterianus Jowitt accessions in relation to Cymbopogon nardus Rendle. 

Genetic Resources and Crop Evolution 47: 553–559. 

Singh A, Singh M, Singh K. 1998. Productivity and economic viability of a palmarosa-pigeonpea intercropping 

system in the subtropical climate of North India. Journal of Agricultural Science 130: 149–154. 

Singh K, Singh DV. 1992. Effect of rates and sources of nitrogen application on yield and nutrient-uptake of 

Java citronella (Cymbopogon winterianus Jowitt). Fertilizer Research 33: 187–191. 

Singh M. 2001. Long-term studies on yield, quality, and soil fertility of lemongrass (Cymbopogon flexuosus) in 

relation to nitrogen application. Journal of Horticultural Science and Biotechnology 76: 180–182. 

Singh M, Rao RSG, Ramesh S. 2005. Effects of nitrogen, phosphorus, and potassium on herbage, oil yield, 

oil quality, and soil fertility status of lemongrass in a semi-arid tropical region of India. Journal of 

Horticultural Science and Biotechnology 80: 493–497. 

Singh M, Rao RSG, Rao EVSP. 1996a. Effect of depth and method of irrigation and nitrogen application on 

herb and oil yields of Java citronella (Cymbopogon winterianus Jowitt) under semi-arid tropical conditions. 

Journal of Agronomy and Crop Science—Zeitschrift fur Acker und Pflanzenbau 177: 61–64. 

Singh M, Shivaraj B. 1998. Intercropping studies in lemongrass (Cymbopogon flexuosus) (Steud, Wats.). 

Journal of Agronomy and Crop Science—Zeitschrift fur Acker und Pflanzenbau 180: 23–26. 

Singh M, Shivaraj B. 1999. Effect of irrigation regimes on growth, herbage and oil yields of lemongrass 

(Cymbopogon flexuosus) under semi-arid tropical conditions. Indian Journal of Agricultural Sciences 

69: 700–702. 

Singh M, Shivaraj B, Sridhara S. 1996b. Effect of plant spacing and nitrogen levels on growth, herb and oil 

yields of lemongrass (Cymbopogon flexuosus (Steud) Wats. var. cauvery). Journal of Agronomy and Crop 

Science—Zeitschrift fur Acker und Pflanzenbau 177: 101–105. 

Singh N, Luthra R, Sangwan RS. 1990. Oxidative pathways and essential oil biosynthesis in the developing 

Cymbopogon flexuosus leaf. Plant Physiology and Biochemistry 28: 703–710. 

Singh N, Luthra R, Sangwan RS. 1991. Mobilization of starch and essential oil biogenesis during leaf ontogeny 

of lemongrass (Cymbopogon flexuosus Stapf). Plant and Cell Physiology 32: 803–811.


Singh RS, Bhattacharyya TK, Kakti MC, Bordoloi DN. 1992. Effect of nitrogen, phosphorus and potash on 

essential oil production of palmarosa (Cymbopogon martinii var. motia) under rainfed condition. Indian 

Journal of Agronomy 37: 305–308. 

Singh S, Ram M, Ram D, Sharma S, Singh DV. 1997. Water requirement and productivity of palmarosa on 

sandy loam soil under a sub-tropical climate. Agricultural Water Management 35: 1–10. 

Singh S, Ram M, Ram D, Singh VP, Sharma S, Tajuddin. 2000. Response of lemongrass (Cymbopogon flexuosus) 

under different levels of irrigation on deep sandy soils. Irrigation Science 20: 15–21. 

Singhsangwan N, Farooqi AHA, Sangwan RS. 1994. Effect of drought stress on growth and essential oil metabolism 

in lemongrasses. New Phytologist 128: 173–179. 

Smith BN, Brown WV. 1973. The Kranz syndrome in the Gramineae as indicated by carbon isotopic ratios. 

American Journal of Botany 60: 505–513. 

Spies JJ, Troskie TH, Vandervyver E, Vanwyk SMC. 1994. Chromosome studies on African plants—11. The 

tribe Andropogoneae (Poaceae, Panicoideae). Bothalia 24: 241–246. 

Sprengel CPJ. 1815. Cymbopogon. Plantarum Minus Cognitarum Pugillus 2: 14. 

Srivastava NK, Misra A, Sharma S. 1998. The substrate utilization and concentration of C-14 photosynthates 

in citronella under Fe deficiency. Photosynthetica 35: 391–398. 

Taylor PWJ, Geijskes JR, Ko HL, Fraser TA, Henry RJ, Birch RG. 1995. Sensitivity of random amplified 

polymorphic DNA analysis to detect genetic change in sugarcane during tissue culture. Theoretical and 

Applied Genetics 90: 1165–1173. 

Trevanion SJ, Furbank RT, Ashton AR. 1997. NADP-Malate dehydrogenase in the C 4 plant Flaveria bidentis. 

Plant Physiology 113: 1153–1165. 

Vickery JW. 1935. The leaf anatomy and vegetative characters of the indigenous grasses of N.S. Wales. 

Proceedings of the Linnean Society, N.S.W. 60: 340–373. 

Wallner E, Weising R, Rompf G, Kahl G, Kopp B. 1996. Oligonucleotide finger printing and RAPD analysis 

of Achillea species: characterisation and long term monitoring of micropropagated clones. Plant Cell 

Reports 15: 647–652. 

Welsh JM, McClelland M. 1990. Fingerprinting genomes using PCR with arbitrary primers. Nucleic Acids 

Research 18: 7213–7218. 

Yang H, Tabei Y, Kamad H, Kayano T, Takaiwa F. 1999. Detection of somaclonal variation in cultured rice cell 

using digoxigenin-based random amplified polymorphic DNA. Plant Cell Reports 18: 520–526.

2 

contents 

Chemistry and Biogenesis 

of Essential Oil from 

the Genus Cymbopogon 

Anand Akhila 

2.1 Introduction ............................................................................................................................26 

2.2 Chemistry and Biogenesis of Essential Oil from Cymbopogons ...........................................26 

2.3 Physicochemical Characteristics of the Essential Oils from Cymbopogons ..........................27 

2.4 Chemistry and Uses of Cymbopogon Essential Oils ..............................................................68 

2.4.1 Lemongrass Oils .........................................................................................................68 

2.4.1.1 Cymbopogon flexuosus ................................................................................68 

2.4.1.2 Cymbopogon citratus ...................................................................................69 

2.4.1.3 Cymbopogon pendulus ................................................................................ 71 

2.4.2 Citronella Oils ............................................................................................................. 71 

2.4.2.1 Cymbopogon winterianus ............................................................................ 71 

2.4.2.2 Cymbopogon nardus ....................................................................................72 

2.4.3 Palmarosa and Gingergrass Oils ................................................................................73 

2.4.3.1 Cymbopogon martinii ..................................................................................73 

2.4.4 Cymbopogon jwarancusa ........................................................................................... 74 

2.4.5 Cymbopogon schoenanthus ........................................................................................ 75 

2.4.6 Other Cymbopogon Species ....................................................................................... 75 

2.4.6.1 Cymbopogon caesius ................................................................................... 75 

2.4.6.2 Cymbopogon coloratus ................................................................................ 75 

2.4.6.3 Cymbopogon confertiflorus ......................................................................... 75 

2.4.6.4 Cymbopogon densiflorus ............................................................................. 76 

2.4.6.5 Cymbopogon distans ................................................................................... 76 

2.4.6.6 Cymbopogon khasianus ...............................................................................77 

2.4.6.7 Cymbopogon ladakhensis ............................................................................77 

2.4.6.8 Cymbopogon microstachys ..........................................................................77 

2.4.6.9 Cymbopogon nervatus .................................................................................77 

2.4.6.10 Cymbopogon olivieri ...................................................................................77 

2.4.6.11 Cymbopogon parkeri ................................................................................... 78 

2.4.7 Some Lesser-Known Species ...................................................................................... 78 

2.4.7.1 Cymbopogon polyneuros ............................................................................. 78 

2.4.7.2 Cymbopogon procerus ................................................................................. 78 

2.4.7.3 Cymbopogon rectus ..................................................................................... 78 

2.4.7.4 Cymbopogon sennarensis ............................................................................ 78 

2.4.7.5 Cymbopogon stracheyi ................................................................................ 78 

2.4.7.6 Cymbopogon tortilis .................................................................................... 78 

2.4.7.7 Cymbopogon travancorensis ....................................................................... 78 

25


2.4.7.8 Cymbopogon goeringii ................................................................................79 

2.4.7.9 Cymbopogon asmastonii .............................................................................79 

2.4.7.10 Cymbopogon giganteus ...............................................................................79 

2.4.8 Biosynthesis of Terpenes in Cymbopogon Species ....................................................79 

2.4.9 Biological Activities....................................................................................................84 

2.4.9.1 Pain Reliever ................................................................................................89 

2.4.9.2 Activity against Leukemia and Malignancy ................................................ 91 

2.4.9.3 Activation of Male Hormones ...................................................................... 91 

2.4.9.4 Activity against Worms ............................................................................... 91 

2.4.9.5 Lowering Blood Sugar ................................................................................. 91 

2.4.9.6 Potential to Repel Mosquitoes and Kill the Larvae ..................................... 91 

2.4.9.7 Activity to Reduce Edema ...........................................................................92 

2.4.9.8 Potential to Control Aging Process ..............................................................92 

2.4.9.9 Activity against Pests ...................................................................................93 

2.4.9.10 Activity against Microbes ............................................................................93 

References ........................................................................................................................................95 


Aromatic grasses are one of the chief sources of essential oils. The genus Cymbopogon comprises 

a large number of species, out of which lemongrass, citronella, palmarosa, and few others produce 

oil of commercial importance (Gupta 1969; Gupta and Deniel 1982; Gupta and Jain 1978; Gupta 

et al. 1975). The chemical compounds present in the essential oils of Cymbopogon do not reflect 

the actual olfactory or other properties of the species (Gildemeister and Hoffmann 1956). There are 

instances when distinct species such as lemongrass oils from C. pendulus, C. citratus, and C. flexuosus 

(Anonymous 1958) produce oil of almost identical chemical composition. “Chemical characters 

are like other characters; they work when they work and they don’t work when they don’t work. Like 

all taxonomic characters they attain their value through correlation with other characters,” has been 

rightly quoted by Cronquits (1980). However, most of the Cymbopogon species found all around the 

world produce essential oils that differ widely in their physical properties and chemical constituents. 

The varieties motia and sofia of C. martinii are good examples of such variable characters. 

The Cymbopogon species has great prospects for producing quality essential oils (Arctander 

1960; Han et al. 1971), and it has direct relevance to the perfumery industry with economic benefit 

to humankind. However, the actual potential of cymbopogons has not been exploited to the fullest. 

Though tremendous work has been done regarding Cymbopogon chemistry, a lot more needs to be 

done to make use of the major and minor constituents present in its essential oils, particularly the 

mono- and sesquiterpenes (Chopra et al. 1956). An effort has been made in this chapter to present a 

comprehensive overview of most of the cultivated and wild species of cymbopogons. 

2.2 chemIstry and bIogenesIs oF essentIal oIl From cymboPogons 

About 25 to 30 species are reported in genus Cymbopogon, and many of them are very good 

sources of essential oils of commercial importance. The compounds present in these oils are characteristic, 

but cannot necessarily be used for identification, of the species. Several botanical races 

of these species produce essential oils that are entirely different in their constituents. The essential 

oils of the Cymbopogon species mainly comprises of mono- and sesquiterpenoids and, despite 

their importance, very few high-tech identification techniques (such as GC-MS high resolution) 

have been utilized to identify the minor and trace constituents present in them; further, only a few 

reports are available in the literature. An attempt has been made in this chapter to present a complete 

analysis of most of the essential oils obtained from these Cymbopogon species. Biosynthetic 

pathways to most of the mono- and sesquiterpenes have been discussed. Efforts have also been

Chemistry and Biogenesis of Essential Oil from the Genus Cymbopogon 27 

made to provide complete data on the physicochemical properties of the oil and spectroscopic data 

( 1 13 H2 CNMR) of its individual constituents (Table 2.2 and Table 2.3). During the years 1950 to 

1980, when GC and GC-MS techniques were not frequently available for the analysis of essential 

oils, the most significant data that could have been used was the density, specific gravity, refractive 

index, specific rotation, and solubility of the oil in aqueous alcohol. 

2.3 PhysIcochemIcal characterIstIcs oF the essentIal oIls 

From cymboPogons 

Physical and chemical properties of any essential oil are of prime importance, and chemists are 

now working in an era when highly sophisticated instruments are available for quality and quantity 

analysis. Still, the specific gravity, optical rotation, solubility in dilute alcohol, and the refractive 

index must be determined for all oils and liquid isolates. Before the availability of modern analytical 

techniques, the essential oil chemists were working using their ingenuity, a highly developed 

sense of smell and taste, and analytical ability. Besides the determination of physical and chemical 

properties, other tests have also been carried out, such as ester content, total alcohol determination, 

congealing point, and melting points in the case of solids, which is of great importance. The reported 

values of these constants for the essential oils of Cymbopogon species are shown in Table 2.1, which 

is self-explanatory. This chapter will cater to the needs of students besides researchers and, therefore, 

brief definitions of the physicochemical characteristics, which are highly relevant in testing the 

quality of the essential oils, have been provided. 

Specific gravity—Specific gravity is defined as the ratio of the density of a given solid or liquid 

substance to the density of water at a specific temperature and pressure, typically at 4°C (39°F) 

and 1 atm (14.7 psia). Substances with a specific gravity greater than 1 are denser than water, and 

so (ignoring surface tension effects) will sink in it, and those with a specific gravity less than 1 are 

less dense than water, and hence will float in it. Specific gravity is a special case of relative density, 

with the latter term often preferred in modern scientific writing. Specific gravity (SG) is expressed 

mathematically as 

density of thesubstance ρ 

SG = 

density of water 

ρl 

where ρ is the density of the substance, and ρ1 is the density of water. (By convention ρ, the Greek 

letter rho, denotes density.) 

Refractive index—The refractive index (or index of refraction) of a medium is a measure of 

how much the speed of light (or other waves such as sound waves) is reduced inside the medium. 

For example, typical glass has a refractive index of 1.5, which means that, in glass, light travels 

at 1/1.5 = 0.67 times the speed of light in a vacuum. Two common properties of glass and other 

transparent materials are directly related to their refractive index. First, light rays change direction 

when they cross the interface from air to the material, an effect that is used in lenses and glasses. 

Second, light reflects partially from surfaces that have a refractive index different from that of their 

surroundings. 

Definition: The refractive index n of a medium is defined as the ratio of the phase velocity c of 

a wave phenomenon such as light or sound in a reference medium to the phase velocity vp in the 

medium itself: n = c/νp. 

Specific rotation—The specific rotation of a chemical compound [α] is defined as the observed 

angle of optical rotation α when plane-polarized light is passed through a sample with a path length 

of 1 dm and a sample concentration of 1 g/dL. The specific rotation of a pure material is an intrinsic 

property of that material at a given wavelength and temperature. Values should always be accompanied 

by the temperature at which the measurement was performed and the solvent in which the


table 2.1 major and minor constituents and Physiochemical Properties of essential oils 

obtained from cymbopogon species 

Cymbopogon flexuosus (steud.) Wats. 

Major terpenes—citral-a (geranial; 40%–50%), citral-b (neral; 30%–35%), Atal and Bradu 1976a; De Martinez 1977 

borneol (0%–2%), citronellal (0.37%–8.04%), citronellol (0.44%–4.58%), 

citronellyl acetate (1.2%–3.6%), geraniol (1.73%–40.0%), geranyl acetate 

(1.95%–5.1%), limonene (2.4%–3.7%), and methyl eugenol (20%) 

Myrcene (0.1%–14.2%) Formacek and Kubeczka 1982; Borovik 

and Kuravskaya 1977; Bhattacharya et al. 

1997; Gonzalo and Villarrubia 1973; 

Guenther 1950; Gonzalo 1973; Taskinen 

et al. 1983; Thapa and Agarwal 1989; 

Thapa et al. 1976; Thapa et al. 1981 

Traces—α-bergamotene, β-bisabolene, τ-cadinene, α-cadinol, camphene, Atal and Bradu 1976a; Chiang et al. 1981; 

δ-3-carene, β-caryophyllene, β-caryophyllene oxide, 1,8-cineole, 

Jyrkit 1983; Le and Chu 1976; Foda et al. 

α-curcumene, p-cymene, n-decyldehyde, dipentene, β-elemene, 

1975; Mohammad et al. 1981a, 1981b; 

τ-elemene, elemicin, elemol, farnesol, geranyl formate, α- humulene, Nair et al. 1980a, 1980b; Sobti et al. 

isopulegol, linalool, linalyl acetate, p-menthane, methyl heptenol, methyl 1978c, 1982; Srikulvandhana et al. 1976; 

heptenone, τ-murolene, nerol, nerolidol, neryl acetate, 2-nonanone, 

Zaki et al. 1975; Jyrkit 1983 

cis-β-ocimene, τ-β-ocimene, perillene, phellandrene, α-pinene, β-pinene, 

piperitone, terpinen-4-ol, α-terpineol, and terpinolene 

origin specific gravity ηd [α] d solubility reference 

Cochin 0.899–0.905 at 15° 1.4883–1.488 at 20° +1°25′ to −5°0′ 1.5–3 vol. of Guenther 1950; 

Aldehyde content (a) Bisulfite method 70%–80%; (b) Neutral 70% alcohol Gildemeister and 

sulfite method 65%–80% 

Hoffmann 1956 

Ceylon 0.895–0.908 at 15° 1.483–1.489 at 20° 1° to 5° NA De Sylva 1959 

Aldehyde content 65% to 85% 

Jammu Regional 0.9212 at 18° 1.4895 at 20° −15.2° NA Thapa et al. 1976 

Research 

Laboratory 

(RRL)-57 

Acid value 2.69; ester value 73.01 

Jammu Regional 0.9137 at 18° 1.4887 at 20° −15.5° NA Thapa et al. 1976 

Research 

Laboratory 

(RRL)-59 


Kerala 0.899–0.905 1.480–1.486 at 35° +1°25′ to −5°0′ 75% alcohol Chakrabarti and 

at 35° Ghosh 1974 

Kumaon 0.9651 1.489 NA NA Baslas and Baslas 


1968 

Lucknow 0.8911 at 25° 1.4816 at 30° −1° 1.2 vol. of Virmani and Datta 

Aldehyde content 89% 

70% alcohol 1973 

Lucknow 0.892 at 30° 1.4825 at 30° −1.5° NA Sharma et al. 1972 

Aldehyde content 71.3% 

Odakali 0.8886 at 20° 1.4862 at 20° −0.40° NA Thapa et al. 1981 


Pantnagar 0.8975–0.899 1.483–1.488 1°25′ to 5° 1.2 vol. of Gulati et al. 1976 


70% alcohol 

West Bengal 0.90 1.4803 at 35° +1°30′ 75% alcohol Chakrabarti and 

at 35° Ghosh 1974


table 2.1 (continued) major and minor constituents and Physiochemical Properties 

of essential oils obtained from cymbopogon species 

origin specific gravity η d [α] d solubility reference 

Travancore 0.895–0.908 1.483–1.489 +1°30′ to −5° 3 vol. of 70% 

alcohol 

Indian Standards 

Institution (ISI) 

0.892–0.902 at 

25° 

Anonymous 1950 

1.4802 at 20° −3° to +1° Anonymous 1952 

Cymbopogon jwarancusa (Jones) schult. 

Major terpenes—piperitone (20%–70%) and ∆ 4 -carene (20%–24%), 

citronellal (30%–40%), p- cymene (0.6%–3.5%), geraniol (0.04%–22.5%), 

β-pinene (3.5%), and γ-terpinene (7.5%) 

Traces—alloaromadendrene, cis- and γ-allo-ocimene, α- bisabolene, 

β-bisabolene, borneol, d-cadinene, calamene, camphene, camphor, 

β-caryophyllene, β-caryophyllene oxide, α -chamigrene, 1,8-cineole, 

citronellol, α-cubebene, cuprene, o-cymene, 5,6-dimethyl-5-norbornen- 

2-ol, dipentene, β-elemene, d -elemene, elemol, eucarvone, eudesmol, 

α -farnesene, β-farnesene, fenchone, geranyl acetate, geranyl formate, 

geranyl propionate, germacrene, α-humulene, iso-borneol, kasuralcohol, 

lavendulol, linalool, longifolene, p-mentha-2,8-dien-1-ol, cis- and 

γ-p-mentha -2-en-1-ol methyl heptenone, methyl thymyl ether, 

α-muurolene, myrcene, myrtenal, phellandrene, α-pinene, γ- and 

cis-peperitol, terpinen-4-ol, α-terpineol, terpinolene, γ-thuj -2-en-4-ol, 

verbenone, and β-ylangene 

Ansari and Quadry 1987; Balyan et al. 

1979; Dev et al. 1988; Dhar and Lattoo 

1985; Dhar et al. 1981; Dhar and Dhar 

1997; Guenther 1950; Liu et al. 1981; 

Maheshwari and Mohan 1985; Mathela 

and Pant 1988; Mathela et al. 1986; Nair 

et al. 1982; Saeed et al.1978; Shahi 1992; 

Shahi and Sen 1989; Sobti et al. 1982; 

Thapa et al. 1971; Shahi and Tava 1993 


Not 

specified 

0.9203–0.9228 at 30° 1.481–1.4858 at 30° +51°41′ to 42°48′ at 30° NA Guenther 1948, 

1950 

Acid value 0.7; 

ester value 12.0 

Hazara 0.9203 at 30° 1.481 at 30° +51.65° at 30° NA Anonymous 1950 

Sind 0.923 at 30° 1.4858 at 30° +42.8° at 30° NA Anonymous 1950 

UP 0.909 at 30° 1.4856 at 30° +25.7° at 30° NA Anonymous 1950 

Cymbopogon martinii (roxb.) Wats. 

Major terpenes—geraniol (65%–85%), citral (4%–12%), citronellol 

(6.4%), linalool (2.4%), and geranyl acetate (6%–12%) 

Traces— α-amorphine, β-betulenol, α-betulenol, bicyclogermacrene, 

β-bisabolene, γ-bisabolene, α-cadinene, γ-cadinene, cis- calamene, 

γ-calamene, calacorene, β-curcumene, o-cymene, p-cymene, m-cymene, 

dipentene, β-elemene, γ-elemene, β-farnesene, farnesol, farnesyl acetate, 

formaldehyde, geranyl-n-butyrate, germacrene-B, germacrene-D, 

β-helmiscapene, α-humulene, β-humulene, isovaleraldehyde, limonene, 

methyl heptenone, myrcene, γ-muurolene, nerolidol, 2-nonanol, 

α-phellandrene, α-pinene, β-pinene, selina-4,7-diene, α-selinene, 

β-selinene, d selinene, α-terpinene, γ-terpinene, α-terpineol, β-terpineol, 

and terpinolene 

Gaydou and Raudriamiharisoa 1987; 

Guenther 1950; Mallavarapu et al. 1998; 

Peyron 1972, 1973; Anon. 1973 

Anonymous 1980; Chiang et al. 1981; De 

Martinez 1977; Maheshwari and Mohan 

1985; Mohammad et al. 1981b; Nair et al. 

1980a, 1980b; Nigam et al. 1987; 

Oliveros-Belardo 1989; Sobti et al. 1981, 

1982; Bottani et al. 1987; Naves 1970, 

1971; Opdyke 1974 

(continued on next page)





India 0.8903–0.8911 at 15° 1.4718–1.4738 at 

20° 

−0°5′ to 

1°20′ 

Java 0.891–0.892 — +0°30′ to 

0°42′ 

West 

Bengal 

1.5 vol. of 

70% alcohol 

3.5 vol. of 

60% alcohol 

Anonymous 

1950 

0.89 1.4702 at 35° −4° 75% alcohol Chakrabarti and 

Ghosh 1974 

ISI 0.8778–0.8898 at 25°C 1.4710–1.4755 at 25° −2° to +3° NA Anonymous 

Acid value 3.0; alcohol content 88%–94% 

1952 

Hyderabad 0.889–0.900 1.468–1.4729 −3° to +6° 80% alcohol Chakrabarti and 

Ghosh 1974 

Jammu 0.889 at 15° 1.475 at 20° NA NA Sobti et al. 

Acid value 0.5–3.0; ester value 12.48 

1981 

Lucknow 0.8810 at 25° 1.4722–1.4702 at 25° +1° 2 vol. of 70% Virmani and 

(Pre-winter 

harvest) 

Acid value 0.5; ester value 6.8; geraniol content 93.7% 

alcohol Dutta 1973 

Cymbopogon martinii stapf. 

Major terpenes—geraniol (36%–65%), perillyl alcohol (15%–27%), 

p-menthenols (40%–62%), γ- and cis -carveol (3%–25%), 1,8-cineole 

(9.8%), and iso piperitenol (13.4%) 

Traces—∆ 3 -carene, carveyl acetate, d,l-carvone, caryophyllene oxide, 

p-cymene, dihydrocarveol, γ- and cis-dihydrocarvone, dipentene, 

d-limonene oxide, d-α-phellandrene, α-pinene, piperitone oxide, and 

tricylene 

Boelens 1994; Guenther 1950; Kalia et al. 

1980; Nigam et al. 1965; Sobti et al. 1978; 

Thapa et al. 1971, 1981 


ISI 0.8997–0.9287 at 1.4760–1.4910 −14° to +54° NA Anonymous 1952 

25°C 

at 25° 

Acid value 6.0; alcohol content 36%–60% 

Jammu (wild 0.9646 at 20° 1.4974 at 20° +22.56° NA Kalia et al. 1980 

collection) Acid value 22.4; ester value 92 

Madras 0.900–0.953 at 15° 1.4780–1.4930 −30° to +54° Soluble in 2.3 vol. Gildemeister and 

at 20° 

of 70% alcohol Hoffmann 1956; 


Guenther 1950 

Cymbopogon citratus (d.c.) stapf. 

Major terpenes—citral-a or geranial (10%–48%) and citral-b or 

neral (3%–43%), borneol (5%), geraniol (2.6%–40%), geranyl 

acetate (0.1%–3.0%), linalool (1.2%–3.4%), and nerol 

(0.8%–4.5%) 

Traces—camphene, camphor, α-camphorene, ∆-3-carene, 

caryophyllene, caryophyllene oxide, 1,8-cineole, citronellal, 

citronellol, n-decyldehyde, α,β-dihydropseudoionone, dipentene, 

β-elemene, elemol, farnesal, farnesol, fenchone, furfural, 

iso-pulegol, iso-valeraldehyde, limonene, linalyl acetate, menthol, 

menthone, methyl heptenol, ocimene, α-oxobisabolene, 

β-phellandrene, α-pinene, β-pinene, terpineol, terpinolene, 

2-undecanone, neral, nerolic acid, and geranic acid 

Abdullah et al. 1975; Abegaz et al. 1983; Brazil 

et al. 1971; Baruah et al. 1995; Guenther 1950; 

Idrissi et al. 1993; Thapa et al. 1981; Torres 1993; 

Zheng et al. 1993 

Beech 1977; Crawford et al. 1975; El Tawil and El 

Beih 1982; Hanson et al. 1976; Kusumov and 

Babaev 1983; Liu et al. 1981; Manjoor-i-Khuda 

et al. 1984; Mathela 1991; Neyberg 1953; Nigam 

et al. 1987; Olaniyi et al. 1975; Opdyke 1973; 

Oliveros-Belardo and Aureus 1978, 1979; Rabha 

et al. 1979; Rouesti and Voriate 1960; Sarer et al. 

1983; Sargenti and Lancas 1997; Zamureenka 

et al. 1981





India 0.865–0.914 at 15° −0°10′ to 2°40′ Anonymous 1950 

Belgium 0.8847 at 20° 1.4849 at 20° −0°18′ at 25° Neyberg 1953 

Citral content 71.3% 

Odakali 0.8986 at 20° 1.4910 at 20° −0.62° at 20° 75% alcohol Thapa et al. 1981 


Cymbopogon pendulus (nees ex steud.) Wats. 

Major terpenes—citral-a or geranial (30%–50%), citral-b or neral 

(20%–35%), geranyl acetate (3%–5%), β-caryophyllene (2.1%), 

elemol (2.2%), geraniol (2%–6%), and linalool (3.0%) 

Traces—camphene, ∆ 3 -carene, caryophyllene oxide, citronellal, 

citronellyl acetate, p-cymene, dipentene, β-elemene, methyl 

heptenone, myrcene, β-phellandrene, α-pinene, and β-pinene 

Atal and Bradu 1976a; Balyan et al. 1979; Gulati 

and Garg 1976; Manjoor-i-Khuda et al. 1984, 

1986; Nigam et al. 1975; Pino et al. 1996; 

Rajendrudu and Rama Das 1983; Sobti et al. 

1982; Thapa et al. 1981; Thapa and Agarwal 1989 


Haldwani India 0.9002–0.9152 1.4905–1.4890 −0.36° Soluble in 1.9 Gulati et al. 1976 


vol. of alcohol 

Cymbopogon winterianus Jowitt 

Major terpenes—geraniol (20%–25%), citronellol (4%–10%), 

citronellal (30%–45%), caryophyllene (2.1%), citronellyl acetate 

(3.0%), elemol (6.0%), geranyl acetate (4.2%), linalyl acetate (2.0%), 

methyl-iso-eugenol (2.3%), and nerol (7.7%) 

Traces—borneol, cadinene, l-cadinol, l-camphene, 1-carvone, citral, 

citronellyl butyrate, cymbopol, dipentene, eugenol, farnesol, geranyl 

formate, l-limonene, linalool, methyl heptenone, methyl eugenol, 

α-pinene, sesquicitronellene, terpinene, terpinen-4-1, and thujyl alcohol 

Baslas 1970; Iruthayathas et al. 1977; Pino et al. 

1996; Razdan and Koul 1973; Siddiqui et al. 

1975; Wijesekera et al. 1973a, 1973b 

Anonymous 1973; Chiang et al. 1981; Ganguly 

et al. 1979; Kaul et al. 1977; Liu et al. 1981; 

Singh et al. 1970; Sobti et al. 1982. 


ISI 0.8710–0.8870 at 30° 1.4610–1.4700 

at 30° 

−0°30′–6° Anonymous 1952 

Nilgiri Hills 

Total geraniol 85%–97% 

0.900–0.929 +2°11′ to 

+12°12′ 

Anonymous 1950 

Wild 0.885–0.901 at 15° 1.463–1.475 at 20° −4° to +1°47′ Soluble in 1–2 Gildemeister and 

Total geraniol content 85%–96%; citronellol 25%–54% vol. of alcohol Hoffmann 1956; 

Guenther 1950 

Java 0.897 at 27° 1.4654 at 27.5° −2°34′ at 28° Soluble in Guenther 1948, 

Total geraniol 88.8%; citronellol content 42.7% 

2.5–7.5 vol. of 

70% alcohol 

1950 

Java 0.887–0.895 at15° 1.4685–1.4728 at −0°35′ to 5°6′ Soluble in 1–2 Guenther 1950 

20° 

vol. of 80% 

Total geraniol 82.3%–89.4%; citronellol content 28.8%–43.9% alcohol 

Java 0.900–0.920 1.479–1.494 at 20° −7° to +22° Soluble in 80% Chakrabarti and 

alcohol 

Ghosh 1974 






Pantnagar 0.9009 1.471 Baslas 1970 

Total geraniol content 85.4%; citronellol 32.47% 

Kumaon 0.9095 1.471 Baslas 1968 

Total geraniol content 83.2%; citronellol 32% 

West Bengal 0.912 1.470 at 35° −14°5′ Soluble in 80% 

alcohol 

Bangalore 0.8870 at 24° 1.4660 at 24° −0°30′ Soluble in 1 vol. 

Total geraniol content 65% 

Jorhat 0.890–0.892 at 25° 1.4650–1.4714 at 

25° 

of 80% alcohol 

−3°3′ Soluble in 1.5 

vol. of 80% 

alcohol 

Total geraniol content 85 to 90% 

Lucknow 0.875 at 25° 1.462 at 20° −1°2′ Soluble in 1−2 

Total geraniol content 96% 

Cymbopogon nardus (l.) rendle 

Major terpenes—limonene (9%–28%), geraniol (20%–30%), citronellol 

(8%–20%), citronellal (5%–16%), caryophyllene (1.4%), camphene 

(5%–6%), citral (18%), citronellol (20%), geranyl acetate (7%–8%), 

linalool (8.0%), methyl eugenol (4.1%), α-phellandrene (16.2%), β-pinene 

(15%), sesquicitronellene (5%–6%), and thujyl alcohol (8%–30%) 

Traces—α -bergamotene, l-borneol, citronellyl acetate, citronellyl 

butyrate, dipentene, elemol, ethyl iso-eugenol, eugenol, farnesol, 

n-heptyl alcohol, iso-pulegol, iso-valeraldehyde, methyl heptenone, 

nerol, cis-ocimene, pelargonaldehyde, and tricyclene 

vol. of 80% 

alcohol 

Chakrabarti and 

Ghosh 1974 

Virmani and Dutta 

1971 


1971 


1971 

Bruns et al. 1981; Guenther 1950; Gupta and 

Chauhan 1970; Krishnarajah et al. 1985; 

Manjoor-i-Khuda et al. 1984; Opdyke 1976; 

Razdan 1984 

Bruns et al. 1981; Gulati and Sadgopal 1972; 

Herath et al. 1979; Lucius and Adler 1971; 

Thieme et al. 1980; Wijesekera et al. 1973a, 

1973b 


ISI 0.8870–0.9080 at 30° 

Total alcohol 55%–65% 

1.4745–1.4805 

at 30° 

−9° to −18° Anonymous 1952 

Haldwani 0.9233 1.4820 at 25° +4.06° Gulati and 


Sadgopal 1972 

Nainital 0.8632 at 20° 1.479 at 20° Gupta and 


Chauhan 1970 

Lucknow 0.895 at 30° 1.478 at 30° −12° Sharma et al. 1972 

0.900–0.920 1.479–1.494 

at 20° 

Ceylon 0.899–0.908 at 15° 1.4792–1.4842 

at 20° 

Ceylon 0.898–0.908 at 15° 1.4785–1.4900 

at 20° 

Java 0.885–0.900 at 15.5° 1.465–1.473 

at 20° 

−7° to −22° Soluble in 1–2 

vol. of 80% 

alcohol 

−9°40′ to −14°40′ 

at 20° 

Soluble in 1 vol. 


Gildemeister and 

Hoffmann 1956; 

Guenther 1950 

Guenther 1950 

−7° to −14° Anonymous 1950 

−5° to +1° at 20° Soluble in 3 vol. 


Anonymous 1950




Cymbopogon schoenanthus (l.) spreng subsp. proximus hochst. 

Major terpenes—piperitone (80% amongst monoterpenes), elemol (39%), 

eudesmol (20%) amongst sesquiterpene alcohol, cis-carveol (4.8%), citral-a 

(2.4%), citral- b (3.3%), dihydrocarveol (35%), limonene (3.12%), linalool (21.6%) 

Traces—α-pinene, β-elemene, β-selinene, calamenene, cadalene p hydroxycinnamic 

acid, and several sesquiterpene alcohols 

Dawidar et al. 1990; Elagamal and Wolff 

1987; El Tawil and El Beih 1982; 

Modawi et al. 1984 

Ahmed et al. 1970; Evans et al. 1982; 

Shahi et al. 1990; Siddiqui et al. 1980 


0.9169 at 15°C 1.4831 at 20° −59°22′ Soluble in 0.8 vol. Gildemeister and 

Acid value 6.0; alcohol content 36%−60% 

of 70% alcohol Hoffmann 1956 

Cymbopogon caesius (nees) stapf 

Major terpenes—Perillyl alcohol (25.6%), geraniol (19.8%), limonene (7.2%), 

citronellol (6.8%), and citronellal (6.7%) 

Trace—Carvone (30%) Liu et al. 1981 

α-Thujene, α-pinene, terpinolene, linalool, isopulegol, borneol, terpineol, 

Kanjilal et al. 1995 

geraniol, bornyl acetate, eugenol, citronellyl acetate, geranyl acetate, 

β-caryophyllene, perillaldelyde, caryophyllene oxide, elemol, and guaiol 


Bangalore 0.9267–0.9339 at 

15°C 

1.484 to 1.4856 at 

25° 

−18.3° to −5.6° at 

25° 

Acid value 0.9–2.5; saponification value 13.2–24.0; sap. value after 

acetylation 15.0–164.0 

Cymbopogon coloratus (nees) stapf. 

Monoterpenes—myrcene, limonene, trans-β-ocimene, linalool, neral, 

geranial, geraniol (69.11%), geranyl acetate, and elemol 

Soluble in 

70% alcohol 

Gildemeister 

and Hoffmann 

1956 

Mallavarapu et al. 

1992 


Malabar 

District 

0.911–0.920 at 

15°C 

NA −7°43′ to −10° 

20′ at 25° 

Cymbopogon densiflorus (steud.) stapf. 

Monoterpenes—Flower-limonene (52.1%), trans-p-menth-2,8-dien-1-ol 

(10%), verbenol (9.7%), and perillyl alcohol (7.2%) 

Monoterpenes—Leaf—trans-p-mentha-2,8-dien-1-ol (22.4%), verbenol 

(18%), perillyl alcohol (17.2%), and cis-p-mentha-1-(7)-dien-2-ol (11.1%) 

Soluble in 1 vol. 



Hoffmann 1956 

Boelens 1994; 

Chisowa 1997 


Congo 0.9304 at 15°C 1.4683 at 20° +59°30′ Soluble in 0.5 vol. of Gildemeister and 

Sap. value 2.1; ester value 19.6; ester value 8.42 after acetylation 80% alcohol Hoffmann 1956 

Cymbopogon distans (nees) Wats. 

Major terpenes—terpineol (20%) Sobti et al. 1978 

Piperitone (30%–40%) and geraniol (10%) Liu et al. 1981; 

Thapa et al. 1971 

Limonene (29%) and methyl eugenol (13%), β-bisabolene (5.4%), α-bisabolol 

(3.0%), bornyl acetate (4.8%), γ-cadinene (3.6%), caryophyllene (4.7%), 

d-citronellal (4.0%), p-cymene (5.1%), farnesol (5.1%), d-menthone (10.4%), 

geranyl acetate (10%–12%), α-humulene (3.5%), limonene (5.8%–29.0%), 

methyl eugenol (13.4%), α-phellandrene (2.3%–6.0%), and α-pinene (3.5%) 

Singh and Sinha 

1976 





Traces—amorphine, γ-α-bergamotene, borneol, d-cadinene, camphene, 

1-carbomenthone, citronellol, β-farnesene (a keto compound), β-muurolene, 

myrcene, neryl propionate, octanol β-phellandrene, β-pinene, sabinene, 

β-selinene, α-terpinene, γ-terpinene, and terpinolene 

material was dissolved. Often the temperature is not specified; in these cases it is assumed to be 

room temperature. The formal unit for specific rotation values is deg cm 2 g −1 , but scientific literature 

uses just degrees. A negative value means levorotatory rotation, and a positive value means dextrorotatory 

rotation. 

Optical rotation is measured with an instrument called a polarimeter. There is a linear relationship 

between the observed rotation and the concentration of optically active compound in the 

sample. There is a nonlinear relationship between the observed rotation and the wavelength of light 

used. Specific rotation is calculated using either of two equations, depending on the sample you are 

measuring. For pure liquids, 

[α] λ T = α/l × d 

In this equation, l is the path length in decimeters, and d is the density of the liquid in g/mL, for a 

sample at a temperature T (given in degrees Celsius) and wavelength λ (in nanometers). If the wavelength 

of the light used is 589 nanometer (the sodium D line), the symbol “D” is used. The sign of 

the rotation (+ or −) is always given: [α] D 20 = +6.2°. For solutions, a different equation is used: 

[α] λ T = 100α/l × d 

Balyan et al. 1979; Gupta and Daniel 

1982; Liu et al. 1981; Mathela et al. 

1988; Mathela and Joshi 1981; Mathela 

et al. 1990a; Melkani et al. 1985; Singh 

and Sinha 1976; Sobti et al. 1978c 


Nainital 0.801 — — NA Mathela and Joshi 1981 

Acid value 1.15; ester value after acetylation 80.95 

Cymbopogon nervatus (hohst.) chiov. 

Terpenes—β-selinene, β-elemene, β-bergamotene, and germacrene-D Modawi et al. 

1984 


Kordofan Sudan 0.9405 at 15° 1.4946 at 20° +26°22′ Soluble in 0.5 vol. 


Ester value 9.3, ester value after acetylation 99.1 


Hoffmann 1956 

When using this equation, the concentration and the solvent are always provided in parentheses 

after the rotation. The rotation is reported using degrees, and no units of concentration are given (it 

is assumed to be g/100 mL). 

Solubility—Solubility is a characteristic physical property referring to the ability of a given substance, 

the solute, to dissolve in a solvent. It is measured in terms of the maximum amount of solute 

dissolved in a solvent at equilibrium. The resulting solution is called a saturated solution. Certain 

liquids are soluble in all proportions with a given solvent, such as ethanol in water. This property is 

known as miscibility. Under certain conditions the equilibrium solubility can be exceeded to give a 

so-called supersaturated solution, which is metastable.


table 2.2 1 h and 13 c-nmr data of monoterpenes Found in cymbogon essential oils 

acyclic monoterpene hydrocarbons 

1 h-nmr 13 c-nmr 1 h-nmr 13 c-nmr 

trans-Ocimene—(4Z,6E)-2,6-dimethylocta-2,4,6-triene; chemical formula: 

C10H16; exact mass: 136.13; molecular weight: 136.23, m/z: 136.13 (100.0%), 

137.13 (11.0%); elemental analysis: C, 88.16; H, 11.84 

cis-Ocimene—(4Z,6E)-2,6-dimethylocta-2,4,6-triene; chemical formula: 



H 5.44 

1.71 

22.4 

1.71 

5.43 H 

16.4 

135.2 

135.1 

12.8 

135.1 

H 6.51 

6.44 H 

124.6 

135.2 

124.6 

1.71 

1.71 

12.8 

130.4 

125.4 

130.4 

5.99 H 

H 5.99 

125.4 

H 6.51 

6.44 H 

25.7 

19.7 143.3 

19.7 

143.3 

25.7 

1.71 

1.71 

1.71 

1.71 

β-Phellandrene—3-isopropyl-6-methylenecyclohex-1-ene; chemical 

chemical formula: C10H16; exact mass: 136.13; molecular weight: 136.23, m/z: 

136.13 (100.0%), 137.13 (11.0%); elemental analysis: C, 88.16; H, 11.84 

α-Phellandrene—5-isopropyl-2-methylcyclohexa-1,3-diene; chemical chemical 

formula: C10H16; exact mass: 136.13; molecular weight: 136.23, m/z: 136.13 

(100.0%), 137.13 (11.0%); elemental analysis: C, 88.16; H, 11.84 

1.71 

109.7 

H 4.80 

4.88 H 

22.3 

131.0 

H 5.58 

5.97 H 

34.4 

143.9 

124.2 

125.6 

5.90 

2.01;1.91 

124.2 

28.1 

41.9 

134.1 

1.46;1.21 

31.1 

2.15 

134.1 40.3 

2.23;1.98 

5.80 2.13 

5.47 H 

32.0 

1.86 

32.0 

1.86 

21.1 21.1 

1.01 1.01 

21.2 21.2 

1.01 1.01 



table 2.2 (continued) 1 h and 13 c-nmr data of monoterpenes Found in cymbogon essential oils 

acyclic oxygenated monoterpenes 

Citral-a-(Z)-3,7-dimethylocta-2,6-dienal; chemical formula: C10H16O; exact Citral-b-(E)-3,7-dimethylocta-2,6-dienal; chemical formula: C10H16O; exact 

mass: 152.12; molecular weight: 152.23, m/z: 152.12 (100.0%), 153.12 


(10.9%); elemental analysis: C, 78.90; H, 10.59; O, 10.51 


9.68 H 

O 

(Z) 

2.00 

1.71 

2.00 

5.77 

H 5.20 

O 

23.0 

5.77 H 9.68 

164.5 

(Z) 

(E) 

33.2 

127.7 

2.00 

1.71 

26.1 191.1 

123.5 O 

2.00 H 5.20 

17.0 

164.5 191.1 

39.2 (E) 

127.7 

O 

26.1 

123.5 

132.0 

19.6 25.6 

132.0 

19.6 25.6 

1.71 1.71 

1.71 1.71


Citronellal—3,7-dimethyloct-6-enal; chemical formula: C10H18O; exact mass: 

154.14; molecular weight: 154.25, m/z: 154.14 (100.0%), 155.14 (11.1%); 

elemental analysis: C, 77.87; H, 11.76; O, 10.37 

Citronellol—3,7-dimethyloct-6-en-1-ol; chemical formula: C10H20O; exact 



1.06 

20.6 

O 

4.78 

OH 

1.06 

21.1 

202.1 

27.6 

9.72 

1.88 

60.3 

29.3 

3.53 

1.65 

1.29 

O 

37.5 

51.0 

2.48;2.23 

OH 

38.0 

1.44 

1.29 

39.9 

24.1 

H 5.20 

1.96 

24.4 

126.8 

H 5.20 

1.96 

126.8 

131.3 

19.6 25.6 

131.3 

19.6 25.6 

1.71 1.71 

1.71 1.71 

Citronellyl butyrate—8-butoxy-2,6-dimethyloct-2-ene; chemical formula: 

C14H28O; exact mass: 212.21; molecular weight: 212.37, m/z: 212.21 

(100.0%), 213.22 (15.5%), 214.22 (1.3%); elemental analysis: C, 79.18; H, 

13.29; O, 7.53 

Citronellyl acetate—3,7-dimethyloct-6-enyl acetate; chemical formula: 

C12H22O2; exact mass: 198.16; molecular weight: 198.3, m/z: 198.16 (100.0%), 

199.17 (13.3%), 200.17 (1.2%); elemental analysis: C, 72.68; H, 11.18; O, 

16.14 

14.1 

0.96 

2.01 

19.0 

32.2 

1.33 

O 

1.46 

20.8 

29.5 

O O 

1.06 

62.4 

72.1 

O 

69.9 

21.1 

1.06 3.37 

O 

1.65 

3.37 

1.42 

H 5.20 

170.2 20.7 

O 

36.6 

37.7 

4.08 

1.65 

29.6 

24.4 

1.53 

H 5.20 

1.29 

38.0 

37.7 

1.29 

126.8 

24.4 

1.96 

126.8 

1.96 

19.6 131.3 25.6 

19.6 131.3 25.6 

1.71 1.71 

1.71 1.71 




Lavandulol—5-methyl-2-(prop-1-en-2-yl)hex-4-en-1-ol; chemical formula: 


(100.0%), 155.14 (11.1%); elemental analysis: C, 77.87; H, 11.76; O, 10.37 

Geraniol—(E)-3,7-dimethylocta-2,6-dien-1-ol; chemical formula: C10H18O; exact mass: 154.14; molecular weight: 154.25, m/z: 154.14 (100.0%), 155.14 


107.5 

5.56 

OH 

H 4.88 

4.63 H 

5.39 H 

65.2 

50.0 

3.65;3.40 

2.29 

4.78 

2.09;1.84 

HO 

4.20 

21.5 

149.1 

HO 

1.71 

25.7 

1.71 

2.00 

124.2 

H 5.20 

5.20 H 

2.00 

131.4 

19.6 25.6 

1.71 1.71 

1.71 

1.71 

Geranyl formate—(Z)-3,7-dimethylocta-2,6-dienyl formate; chemical 

formula: C11H18O2; exact mass: 182.13; molecular weight: 182.26, m/z: 


17.56 

Geranyl acetate—(Z)-3,7-dimethylocta-2,6-dienyl acetate; chemical formula: 

C12H20O2; exact mass: 196.15; molecular weight: 196.29, m/z: 196.15 (100.0%), 


16.30 

23.2 

O 

23.2 

1.71 

4.75 

5.39 H 

135.7 

135.7 

2.01 

O 

123.0 

33.4 

H 

1.71 

5.20 

1.71 

O 

123.0 

33.4 

160.7 

4.83 

2.00 

60.4 

123.5 O 170.2 20.8 

H 5.20 

1.71 

2.00 

26.4 

O 

8.04 

O 

26.4 

O O 

62.9 

123.5 

2.00 

2.00 

H 

5.39 

19.6 132.0 25.6 

19.6 132.0 25.6 

1.71 

1.71


Linalyl acetate—3,7-dimethylocta-1,6-dien-3-yl acetate, chemical formula: 

C12H20O2; exact mass: 196.15; molecular weight: 196.29, m/z: 196.15 

(100.0%), 197.15 (13.3%), 198.15 (1.2%); elemental analysis: C, 73.43; H, 

10.27; O, 16.30 

Linalool—3,7-dimethylocta-1,6-dien-3-ol, chemical formula: C10H18O; exact 



28.7 

5.23 

H 

25.4 

OH 

170.2 21.4 

O 

1.71 

73.2 

H 5.89 

82.9 

2.01 

145.7 

O 

112.6 

O 

H 

1.60 

5.20 

145.7 

42.9 

OH 2.0 

5.24 H 

39.6 

O 

1.71 

18.5 

H 5.89 

1.96 

1.41 

1.48 

112.6 

18.3 

126.8 

1.57 

126.8 

H 5.20 

1.96 

H 5.24 

5.23 H 

19.6 

131.3 

25.6 

131.3 

19.6 25.6 

1.71 1.71 

Neryl acetate—(E)-3,7-dimethylocta-2,6-dien-1-ol; chemical formula: 



Nerol—(Z)-3,7-dimethylocta-2,6-dien-1-ol; chemical formula: C10H18O; exact 



19.7 

17.5 

1.71 

120.0 

2.01 

1.71 

58.9 

135.7 

H 5.20 

1.71 

129.7 

29.9 

OH 

123.0 

39.7 

O O 

H 

1.71 

5.20 

1.71 

2.00 

20.8 

2.00 

168.0 

O 

123.5 

26.1 

4.75 

2.00 

26.4 

H 5.39 

2.00 

123.5 

H 5.39 

1.71 

O 

19.6 

132.0 

25.6 

4.20 

19.6 132.0 25.6 

5.56 HO 




6-methylhept-5-en-2-one—chemical formula: C8H14O; exact mass: 126.1; 

molecular weight: 126.2, m/z: 126.10 (100.0%), 127.11 (8.9%); elemental 

analysis: C, 76.14; H, 11.18; O, 12.6 

2.09 

31.0 

207.7 

O 

44.8 

O 

2.49 

22.2 

H 5.20 

2.24 

123.5 

132.0 

19.6 25.6 

1.71 1.71 

65 

cyclic monoterpene hydrocarbons 

p-Cymene—chemical formula: C10H14; exact mass: 134.11; molecular weight: o-Cymene—chemical formula: C10H14; exact mass: 134.11; molecular weight: 

134.22, m/z: 134.11 (100.0%), 135.11 (10.8%); elemental analysis: C, 89.49; H, 134.22, m/z: 134.11 (100.0%), 135.11 (10.8%); elemental analysis: C, 89.49; 

10.51 

H, 10.51 

2.19 

24.3 

125.9 

7.06 

135.6 

125.5 

128.7 

6.99 

6.98 

6.98 

6.98 

128.7 

128.7 

7.01 

126.0 

7.19 7.19 

126.0 

126.0 

133.9 

2.35 

146.2 22.4 

145.5 

3.12 

33.8 

2.86 

36.3 

1.29 1.29 

1.19 1.19 

23.3 23.3 

23.6 23.6


(−)-Limonene—(S)-1-methyl-4-(prop-1-en-2 yl)cyclohex-1-ene; chemical 



(+)-Limonene—(R)-1-methyl-4-(prop-1-en-2 yl)cyclohex-1-ene; chemical 



1.71 

23.1 

1.71 

23.1 

H 5.37 

H 5.37 

133.9 

2.01;1.91 

133.9 

2.01;1.91 

123.3 

31.0 

123.3 

31.0 

1.77;1.52 2.33 2.09;1.84 

2.09;1.84 

1.77;1.52 2.33 

31.1 

31.1 

42.3 

28.1 

42.3 

28.1 

H 4.63 

H 4.63 

149.1 

1.71 

149.1 

1.71 

21.5 107.5 

4.88 

H 

21.5 107.5 

H 4.88 

α-Terpinene—1-isopropyl-4-methylcyclohexa-1,3-diene; chemical formula: 



Myrcene—7-methyl-3-methyleneocta-1,6-diene; chemical formula: C10H16; exact mass: 136.13; molecular weight: 136.23, m/z: 136.13 (100.0%), 137.13 

(11.0%); elemental analysis: C, 88.16; H, 11.84 

23.2 

1.71 

116.1 

H 5.02 

138.3 

145.3 

H 5.68 

H 6.25 

143.9 

5.16 H 

120.1 

31.7 

2.15 

110.4 

38.2 

H 4.88 

115.5 

26.1 

2.15 

2.00 

26.5 

142.7 

H 5.68 

123.5 

H 

4.80 

2.00 

5.20 H 

34.5 

2.52 

21.9 21.9 

19.6 132.0 25.6 

1.11 1.11 

1.71 

1.71 




Terpinolene—1-methyl-4-(propan-2-ylidene) cyclohex-1-ene; chemical 



γ-Terpinene—1-isopropyl-4-methylcyclohexa-1,4-diene; chemical formula: 



23.2 

1.71 

23.2 

1.71 

132.1 

H 5.21 

131.5 

H 5.16 

120.5 

31.7 

2.00 

121.3 

37.8 

2.63 

30.2 

125.8 

28.1 

2.63 

2.00 

32.2 

116.7 

2.63 

140.7 

5.16 H 

34.5 

2.52 

19.5 125.3 19.5 

21.9 21.9 

1.11 1.11 

1.71 1.71 

bicyclic monoterpene hydrocarbons 

∆4-Carene —3,7,7-trimethylbicyclo[4.1.0]hept-2-ene; chemical formula: 



∆3-Carene—3,7,7-trimethylbicyclo[4.1.0]hept-3-ene; chemical formula: C10H16; exact mass: 136.13; molecular weight: 136.23, m/z: 136.13 (100.0%), 137.13 

(11.0%); elemental analysis: C, 88.16; H, 11.84 

23.4 

1.71 

23.4 

1.71 

133.9 

133.9 

H 5.37 

5.37 H 

124.2 

30.9 

36.4 

2.01;1.91 

123.3 

2.04;1.79 

30.3 

25.3 

0.87 

1.74;1.49 

25.5 

30.3 

0.22 

2.04;1.79 

36.4 

0.22 

28.3 

0.22 

27.7 

24.9 

1.11 

27.4 

23.6 

1.11 

27.7 

1.11 

1.11 

27.4


α-Pinene—2,6,6-trimethylbicyclo[3.1.1]hept-2-ene; chemical formula: 



21.2 

1.71 

Camphene—2,2-dimethyl-3 methylenebicyclo[2.2.1]heptane; chemical 



24.8 

1.21 

48.4 

1.52 

135.7 

42.3 

H 5.37 

1.60;1.35 

31.5 

1.21 

H 4.88 

1.60;1.35 

123.3 

48.9 

2.62 

24.8 

39.6 

1.63;1.38 

25.2 

41.5 

1.11 

2.04;1.79 

1.11 

25.2 

2.04;1.79 

34.5 

2.19 

30.3 

31.3 

165.0 

1.97 

109.1 

46.6 

H 4.63 

41.2 

Sabienene—1-isopropyl-4 methylenebicyclo[3.1.0]hexane; chemical formula: 



β-Pinene—6,6-dimethyl-2 methylenebicyclo[3.1.1]heptane; chemical formula: 



109.1 

4.76 H H 4.62 

109.1 

4.88 H H 4.63 

35.4 

153.5 

37.4 

0.88 

2.01;1.91 

37.9 

148.0 

52.9 

20.6 

43.9 

2.01;1.91 

41.5 

2.62 

1.38;1.13 0.27;0.02 

25.2 

25.2 

1.11 

43.1 

1.11 

32.3 

31.3 

1.41;1.16 

2.04;1.79 

33.3 

1.81 

43.6 

1.93 

18.6 18.6 

1.01 1.01 




oxygenated monoterpenes 

Carvacrol—(R)-2-methyl-5-(prop-1-en-2-yl)cyclohex-1-enol; chemical cis-Carveol—2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enol; chemical formula: 

formula: C10H16O; exact mass: 152.12; molecular weight: 152.23, m/z: 152.12 C10H16O; exact mass: 152.12; molecular weight: 152.23, m/z: 152.12, 

(100.0%), 153.12 (10.9%); elemental analysis: C, 78.90; H, 10.59; O, 10.51 (100.0%), 153.12 (10.9%); elemental analysis: C, 78.90; H, 10.59; O, 10.51 

16.9 

1.71 

1.71 

(Z) 

136.3 

OH 

71.9 

5.37 3.69 

H (Z) OH 4.14 

OH 16.77 

2.0;1.9 

123.3 

2.09;1.84 2.33 1.92;1.67 

2.1;1.8 

1.8;1.5 2.3 

35.2 

31.4 

36.1 

H 4.63 

H 4.88 

149.1 

1.71 

1.71 

21.5 107.5 

H 4.88 

H 4.63


Carvotanacetone—5-isopropyl-2-methylcyclohex-2-enone; chemical 

formula: C10H16O; exact mass: 152.12; molecular weight: 152.23, m/z: 152.12 


Carveyl acetate—2-methyl-5-(prop-1-en-2-yl) cyclohex-2-enyl acetate; 

chemical formula: C12H18O2; exact mass: 194.13; molecular weight: 194.27, 

m/z: 194.13 (100.0%), 195.13 (13.1%); elemental analysis: C, 74.19; H, 9.34; 

O, 16.47 

15.9 

1.93 

1.71 

17.1 

135.4 

O 

2.01 

(Z) 4.43 O 

5.37 H 

137.3 

O H 6.35 

170.2 21.1 

O 

198.9 

75.7 

136.3 

(Z) 

123.3 

O 

2.09;1.84 2.33 

2.01;1.76 

30.1 

45.9 

40.5 

O 3.03;2.78 1.73 2.04;1.79 

31.1 36.3 31.9 

H 4.63 

149.1 

21.5 107.5 

1.71 

1.82 

31.6 

1.01 1.01 

H 

4.88 

20.8 20.8 

Eucarvone—(2Z,4Z)-2,6,6-trimethylcyclohepta-2,4-dienone; chemical 



Carvone—2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enone; chemical formula: 

C10H14O; exact mass: 150.1; molecular weight: 150.22, m/z: 150.10 (100.0%), 

151.11 (11.0%); elemental analysis: C, 79.96; H, 9.39; O, 10.65 

1.93 

29.6 

15.9 

1.21 

1.21 

O 

135.5 

5.65 2.90 

198.9 

134.7 

H 

H 6.35 

O 

29.6 

151.0 

O 

2.09;1.84 

3.07;2.82 2.43 

O 

36.6 

59.8 

202.6 

137.5 

30.9 

43.2 

41.6 

119.8 

6.21 H 

1.93 

H 4.63 

16.3 

135.6 

H 

7.01 

1.71 

149.1 

21.2 107.5 

H 

4.88 




(−)-Dihdrocarveol—(1R,5R)-2-methyl-5-(prop-1-en-2-yl)cyclohexanol; 

chemical formula: C10H18O; exact mass: 154.14; molecular weight: 154.25, 

m/z: 154.14 (100.0%), 155.14 (11.1%); elemental analysis: C, 77.87; H, 

11.76; O, 10.37 

1,8-Cineole—1,3,3-trimethyl-2 oxabicyclo [2.2.2]octane; chemical formula: 



14.5 

1.06 

1.31 

OH 4.81 

1.69 

OH 

40.1 

3.16 

1.52;1.27 

77.9 

27.8 

1.53 

1.65;1.40 

1.57;1.32 2.12 1.72;1.47 

O 

38.0 

40.1 

28.6 

1.52;1.27 1.74 1.40 

H 4.67 

1.71 

147.7 

H 

4.66 

1.26 1.26 

21.4 110.6 

6,7-Epoxy-3,7-dimethyl-1,3-octadiene—(Z)-2,2-dimethyl-3-(3-methylpenta- 

2,4-dienyl)oxirane; chemical formula: C10H16O; exact mass: 152.12; molecular 

weight: 152.23, m/z: 152.12 (100.0%), 153.12 (10.9%); elemental analysis: C, 

78.90; H, 10.59; O, 10.51 

22.3 

3,4-Epoxy-3,7-dimethyl-1,6-octadiene—2-methyl-3-(3-methylbut-2-enyl)-2vinyloxirane; 

chemical formula: C10H16O; exact mass: 152.12; molecular 


78.90; H, 10.59; O, 10.5 

22.1 

1.71 

O 

1.41 

133.6 

60.2 

O 

H 6.25 

5.25 H 

138.3 

132.8 

145.7 

64.8 

H 5.89 

2.59 

116.1 

67.1 

26.3 

2.21;1.96 

H 

O 5.16 

112.6 

126.8 

26.3 

2.21;1.96 

5.20 H 

H 5.02 

2.55 

H 5.23 

5.24 H 

O 

58.8 

1.26 

1.26 

1.71 

1.71 

23.3 23.3 

131.3 

19.6 25.6


cis-Isopiperitenol—(1S,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-2-enol, 



10.59; O, 10.51 

1.71 

23.4 

Isopiperitenone—(R)-3-methyl-6-(prop-1-en-2-yl)cyclohex-2-enone; chemical 


(100.0%), 151.11 (11.0%), elemental analysis: C, 79.96; H, 9.39; O, 10.65 

1.71 

133.9 

H 5.37 

H 5.85 

2.01;1.91 

2.01;1.91 

122.9 

31.3 

3.72 

1.77;1.52 2.41 

1.57;1.32 3.03 

71.3 

21.9 

OH 4.14 

O 

51.6 

OH 

H 4.63 

H 4.97 

1.71 

1.71 

149.1 

H 

4.88 

H 4.89 

21.8 107.5 

Isopulegol—(1S,2R,5S)-5-methyl-2-(prop-1-en-2-yl)cyclohexanol; chemical 



trans-Isopiperitenol—(1S,6R)-3-methyl-6-(prop-1-en-2-yl)cyclohex-2-enol; 

chemical formula: C10H16O; exact mass: 152.12; molecular weight: 152.23, m/z: 


10.51 

21.0 

1.71 

1.06 

1.06 

H 5.37 

43.0 

28.4 

1.67;1.42 

1.61 

2.01;1.91 

34.3 

1.52;1.27 

1.67;1.42 

1.61 

1.52;1.27 

1.57;1.32 2.20 3.20 

3.72 

70.4 

1.77;1.52 2.41 

52.7 

22.1 

OH 4.81 

3.16 

1.52;1.27 

1.50 

OH 4.14 

OH 

H 4.67 

147.7 

1.71 

OH 

4.81 

H 4.63 

1.71 

21.7 110.6 

H 

4.66 

1.82 

1.01 1.01 

(continued on next page) 

H 4.88



∆3-Menthene-3-one—5-methylene-2-(prop-1-en-2-yl)cyclohexanone; chemical formula: C10H14O; exact mass: 150.1; molecular weight: 150.22, 


O, 10.65 

Limonene oxide—(1R,4R,6S)-1-methyl-4-(prop-1-en-2-yl)-7-oxabicyclo[4.1.0] 

heptane; chemical formula: C10H16O; exact mass: 152.12; molecular weight: 

152.23, m/z: 152.12 (100.0%), 153.12 (10.9%); elemental analysis: C, 78.90; H, 

10.59; O, 10.51 

110.7 

4.89 H H 4.97 

20.7 

1.31 

O 

O 

2.01;1.91 

2.86 

1.65;1.40 

51.5 

147.4 

3.17;3.07 

64.6 

62.6 

37.8 

35.5 

1.74;1.49 3.03 

1.57;1.32 2.12 1.70;1.45 

207.1 

58.0 

25.2 

O 

31.4 

42.2 

24.2 

O 

4.97 H 

H 4.67 

1.71 

1.71 

143.7 

147.7 

20.9 

110.7 

H 

4.89 

110.6 

21.4 

H 

4.66 

C 

Menthyl acetate—(1R,2S,5R)-2-isopropyl-5-methylcyclohexyl acetate; 


m/z: 198.16 (100.0%), 199.17 (13.3%), 200.17 (1.2%); elemental analysis: C, 

72.68; H, 11.18; O, 16.14 

(−)-Menthol—(1R,2S,5R)-2-isopropyl-5 methylcyclohexanol; chemical 



21.0 

20.7 

1.06 

1.06 

42.9 

28.3 

34.2 

O 

39.6 

28.5 

33.9 

1.52;1.27 1.61 1.76;1.51 

O 

1.52;1.27 2.01 3.90 

O 

1.67;1.42 

1.61 

1.52;1.27 

75.3 

22.3 47.1 

72.2 

22.1 50.4 

1.52;1.27 1.50 3.16 

170.2 

O 

21.0 

OH 

OH 4.81 

2.01 

21.0 25.7 21.0 

1.01 1.82 1.01 

25.5 

1.01 1.82 1.01 

21.3 

21.3


p-Menth-2-en-1-ol—(1R,4R)-4-isopropyl-1 methyl cyclohex-2-enol; 



11.76; O, 10.37 

1.41 

OH 2.0 

28.6 

OH 

(−)-Menthone—(2S,5R)-2-isopropyl-5-methylcyclohexanone; chemical 

formula: C10H18O; exact mass: 154.14, Molecular Weight: 154.25, m/z: 154.14 


20.2 

1.06 

132.4 

68.5 

37.4 

5.59 

49.6 

33.9 

1.88;1.63 

32.6 

2.31;2.06 

1.97 

1.88;1.63 

131.3 

42.1 

20.2 

1.74;1.49 1.94 5.59 

211.5 

59.3 

24.0 

1.88;1.63 2.20 

O 

O 

1.01 

1.86 

1.01 

25.5 

20.5 20.5 

1.01 

2.05 

1.01 

31.9 

21.1 21.1 

cis-p-Menth-1(7),8-dien-2-ol—(1S,5S)-2-methylene-5-(prop-1-en-2-yl) 

cyclohexanol; chemical formula: C10H16O; exact mass: 152.12; molecular 


78.90; H, 10.59; O, 10.51 

p-Menth-8-en-1-ol—(1s,4s)-1-methyl-4-(prop-1-en-2-yl)cyclohexanol; 



10.37 

4.96 H H 5.01 

1.31 

109.1 

27.3 

OH 

4.14 

OH 4.64 

OH 

OH 

1.67;1.42 

1.67;1.42 

3.90 

2.01;1.91 

42.1 

71.0 

75.8 

149.3 

31.8 

42.1 

1.61;1.36 

1.46;1.21 2.16 

1.57;1.32 2.12 1.57;1.32 

43.2 

32.5 38.9 

22.1 

46.6 

22.1 

H 

4.88 

H 4.67 

149.1 

21.4 107.5 

1.71 

1.71 

147.7 

4.88 

H 

4.63 

21.4 110.6 

H 

4.66 




Perillaldehyde—(R)-4-(prop-1-en-2-yl)cyclohex-1-enecarbaldehyde; 



O, 10.65 

p-Menth-2,8-dien-1-ol—(1R,4S)-1-methyl-4-(prop-1-en-2-yl)cyclohex-2-enol; 



10.51 

1.41 

O 

O 

9.68 

28.6 

OH 2.0 

192.9 

OH 

H 6.54 

141.3 

2.01;1.91 

5.59 

1.88;1.63 

132.4 

68.6 

145.6 

20.5 

37.5 

2.09;1.84 

1.77;1.52 2.33 

1.77;1.52 2.64 5.59 

30.9 

27.9 42.0 

131.7 

48.4 

21.4 

4.88 H 

H 4.67 

1.71 

146.3 

1.71 

107.5 149.1 21.5 

H 

4.63 

21.5 110.6 

H 

4.70 

Methyl thymyl ether—1-isopropyl-2-methoxy-4-methylbenzene; chemical 



24.6 

2.35 

136.6 

112.7 

121.0 

6.49 

6.84 

127.0 

7.18 

O 

155.6 

133.4 

O 

30.4 

56.1 

3.12 

3.73 

1.29 1.29 

23.6 23.6


Perillyl alcohol—(4-(prop-1-en-2-yl)cyclohex-1-enyl)methanol; chemical 



Perillene—3-(4-methylpent-3-enyl)furan; chemical formula: C10H14O; exact 

mass: 150.1; molecular weight: 150.22, m/z: 150.10 (100.0%), 151.11, (11.0%); 


OH 

OH 5.56 

142.8 

110.7 

7.23 

6.13 

66.7 

4.20 

137.1 

H 5.58 

O 

125.0 

O 

2.01;1.91 

122.5 

24.8 

139.3 

28.7 

2.59 

2.09;1.84 

1.77;1.52 2.33 

7.11 

31.4 

28.4 42.3 

28.1 

H 5.20 

2.29 

4.88 H 

123.5 

1.71 

149.1 

21.5 

107.5 

H 

4.63 

19.6 132.0 25.6 

1.71 1.71 

Piperitenone—3-methyl-6-(propan-2-ylidene)cyclohex-2-enone; chemical 



cis-Piperitenol—(1S,6R)-3-methyl-6-(prop-1-en-2-yl)cyclohex-2-enol; 



10.51 

1.71 

22.6 

1.71 

23.4 

H 5.37 

166.8 

H 6.17 

133.9 

2.01;1.91 

126.4 

31.5 

2.00 

122.9 

31.3 

3.72 

1.77;1.52 2.41 

187.2 

15.5 123.9 

2.00 

71.3 

21.9 51.6 

OH 4.14 

O 

O 

OH 

H 4.63 

149.1 

1.71 

18.9 

150.2 

18.9 

1.71 1.71 

21.8 107.5 

H 

4.88 




trans-Piperitol—(1R,6R)-6-isopropyl-3-methylcyclohex-2-enol; chemical 



23.4 

1.71 

cis-Piperitol—(1S,6R)-6-isopropyl-3-methylcyclohex-2-enol; chemical 



1.71 

23.4 

133.9 

H 5.37 

133.9 

H 5.37 

122.9 

31.2 

2.01;1.91 

122.9 

31.2 

2.01;1.91 

71.2 

19.1 47.4 

3.68 

1.71 

1.74;1.49 

19.1 47.4 71.2 

OH 

3.68 

1.74;1.49 1.71 

OH 

OH 

4.14 

OH 

4.14 

25.6 

21.4 21.4 

1.82 

1.01 1.01 

25.6 

21.4 21.4 

1.82 

1.01 1.01 

Piperitone oxide—3-isopropyl-6-methyl-7-oxabicyclo[4.1.0]heptan-2-one; 



O, 19.02 

Piperitone—6-isopropyl-3-methylcyclohex-2-enone; chemical formula: 



20.2 

1.31 

1.71 

O 

66.3 

64.4 

O 

H 5.85 

31.8 

3.38 

2.01;1.76 

2.01;1.91 

208.8 

16.3 53.1 

1.88;1.63 2.20 

1.52;1.27 2.33 

O 

O 

O 

25.8 

2.05 

2.05 

20.5 20.5 

1.01 1.01 

1.01 1.01


Terpin-4-ol—1-isopropyl-4-methylcyclohex-3-enol; chemical formula: 

C10H18O; exact mass: 154.14, molecular weight: 154.25, m/z: 154.14 


23.1 

Pulegone—5-methyl-2-(propan-2-ylidene)cyclohexanone; chemical formula: 



1.06 

1.71 

133.9 

1.88 

H 5.37 

123.3 

24.7 

2.01;1.91 

3.03;2.78 

1.41;1.16 

30.3 71.7 40.8 

OH 

37.6 

1.88;1.63 2.19;1.94 

OH 4.64 

1.90 

2.01;1.91 

O 

14.9 14.9 

1.01 1.01 

1.71 1.71 

β-Terpineol—1-methyl-4-(prop-1-en-2-yl)cyclohexanol; chemical formula: 



α-Terpineol—2-(4-methylcyclohex-3-enyl)propan-2-ol; chemical formula: 



1.31 

27.3 

OH 4.64 

23.1 

1.71 

OH 

71.0 

1.67;1.42 

1.67;1.42 

133.9 

H 5.37 

42.1 

42.1 

123.3 

31.2 

2.01;1.91 

1.57;1.32 2.12 1.57;1.32 

22.1 

46.6 

22.1 

19.1 46.5 24.1 

1.74;1.49 1.71 2.04;1.79 

H 4.67 

147.7 

1.71 

OH 

73.2 

OH 4.64 

21.4 110.6 

27.7 27.7 

1.26 1.26 

H 

4.66 




bicyclic oxygenated monoterpenes 

Borneol—1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol; chemical formula: C10H18O; Bornyl acetate—1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl-acetate; chemical 

exact mass: 154.14; molecular weight: 154.25, m/z: 154.14 (100.0%), 155.14 formula: C12H20O2; exact mass: 196.15; molecular weight: 196.29, m/z: 


196.15 (100.0%), 197.15 (13.3%), 198.15 (1.2%); elemental analysis: C, 

73.43; H, 10.27; O, 16.30 

1.16 

OH 

1.49;1.24 

3.15 

1.11 1.11 

1.52;1.27 

1.67;1.42 

1.42 

4.81 

21.0 

2.01 

13.3 

O 

O 

13.5 

1.16 

170.2 

52.7 OH 

O 

49.4 O 

30.0 50.4 76.1 

19.8 19.8 

1.49;1.24 

3.89 

30.2 50.6 81.8 

1.11 1.11 

23.6 

35.8 

19.5 19.5 

1.52;1.27 

1.76;1.51 23.3 

32.5 

45.2 

1.42 

45.4 

Fenchone—(1S,4R)-1,3,3-trimethylbicyclo[2.2.1]heptan-2-one; chemical 



Camphor—(1S,4S)-1,7,7 trimethylbicyclo[2.2.1]heptan-2-one; chemical 



21.2 

15.6 

1.26 

1.26 

O 

51.5 

O 

O 

61.6 

O 

224.4 

34.1 

37.1 

1.84;1.59 

2.02;1.77 

21.8 

220.0 

31.5 

1.11 

1.84;1.59 

21.8 

1.11 

21.2 

47.0 

28.4 

1.21 

1.60;1.35 

39.0 

2.14;1.89 

1.60;1.35 

1.99 

40.1 

28.4 

30.1 

1.21 

1.99 

21.2 

34.4


Myrtenol—7,7-dimethylbicyclo[2.2.1]hept-2-en-2-yl)methanol; chemical 



56.0 

2.25 

66.0 127.0 

25.2 25.2 

H 5.59 

23.1 

1.11 

OH 

OH 5.56 

20.6 

149.4 

4.20 

1.63;1.38 

1.11 

1.63;1.38 

2.25 

Isoborneol—(1S,2S,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol; chemical 

formula: C10H18O; molecular weight: 154.25, m/z: 154.14 (100.0%), 155.14, 


1.16 

OH 

3.15 

1.49;1.24 

1.11 

1.11 

1.52;1.27 

1.67;1.42 

4.81 

13.3 

52.7 

OH 

76.1 

30.0 

19.8 

19.8 50.4 

23.6 35.8 

64.8 

52.5 

45.2 

1.42 

β-Thujene alcohol—(1S,2S,5R)-5-isopropyl-2-methylbicyclo[3.1.0] 

hexan-2-ol; chemical formula: C10H18O; exact mass: 154.14; molecular 

weight: 154.25, m/z: 154.14 (100.0%), 155.14 (11.1%); elemental analysis: 

C, 77.87; H, 11.76; O, 10.37 

Thujyl alcohol—(1S,3S,4S,5R)-1-isopropyl-4-methylbicyclo[3.1.0] 

hexan-3-ol; chemical formula: C10H18O; exact mass: 154.14; molecular 

weight: 154.25 m/z: 154.14 (100.0%), 155.14 (11.1%); elemental analysis: C, 

77.87; H, 11.76; O, 10.37 

24.8 

HO 

1.31 

4.64 HO 

12.0 

1.06 

41.0 

84.5 

34.1 

OH 

81.6 

OH 4.81 

3.16 

1.67;1.42 

1.50 

51.7 

18.4 

1.69 

1.42 

32.1 

12.0 

1.52;1.27 

1.52;1.27 

49.7 

18.5 

1.67;1.42 

1.52;1.27 

31.2 

31.2 

33.5 

1.81 

33.5 

1.81 

18.5 18.5 

1.01 1.01 

18.5 18.5 

1.01 1.01 




Verbenone—(1R,5R)-4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-one; chemical 



20.7 

1.71 

25.0 

165.0 

1.11 

H 5.85 

125.5 

52.6 

48.7 

2.62 

25.0 

200.8 

1.11 

25.2 

2.15;1.90 

O 

2.80 

O 

58.8


table 2.3 

sesquiterpenes Found in major, minor, and trace amounts in Cymbopogon oils (in alphabetical 

order) 

Acoradiene—(4S)-1,8-dimethyl-4-(prop-1-en-2-yl)spiro[4.5]dec-7-ene; chemical formula: C 15H 24; exact mass: 204.19; 

molecular weight: 204.35, m/z: 204.19 (100.0%), 205.19 (16.5%), 206.19 (1.2%); elemental analysis: C, 88.16; H, 11.84 

1H-NMR 1.06 

1.60;1.35 

1.66 

1.70;1.45 

1.63;1.38 

2.01;1.91 

2.17 

1.71 

2.00;1.75 

H 

H 

4.88 

H 

5.37 

4.63 

1.71 

13C-NMR 16.5 

32.5 

41.5 

28.6 

27.1 

67.4 

54.4 

36.4 

22.0 

147.7 

123.3 

110.6 

Alloaromadendrene—(1aR,4aS,7R,7bS)-1,1,7-trimethyl-4-methylenedecahydro-1H-cyclopropa[e]azulene; chemical 

formula: C 15H 24; exact mass: 204.19; molecular weight: 204.35, m/z: 204.19 (100.0%), 205.19 (16.5%), 206.19 (1.2%); 

elemental analysis: C, 88.16; H, 11.84 

1.60;1.35 

1.06 

4.88 H 

2.18 

H 

1.63;1.38 

1.51 

1.67 0.17 

H 4.63 

1.11 

2.01;1.91 

0.18 

1.41;1.16 

1.11 

34.9 

18.9 

29.8 

109.1 

29.1 

133.9 

H 

36.2 

148.7 

50.9 

30.4 

58.6 

39.4 24.1 

Aromadendrene—(1aR,4aR,7R,7bS)-1,1,7-trimethyl-4-methylenedecahydro-1H-cyclopropa[e]azulene; chemical 



4.88 H 

2.18 

H 

1.63;1.38 

1.60;1.35 

1.06 

1.51 

1.67 0.17 

H 4.63 

1.11 

2.01;1.91 

0.18 

1.41;1.16 

1.11 

34.9 

18.9 

29.8 

H 

109.1 

58.6 

39.4 24.1 

27.9 

148.7 

50.9 

27.9 

23.4 

19.2 

36.2 

23.4 

19.2 

30.4 

27.9 

27.9 

23.1 





order) 

α-Bergamotene—2,6-dimethyl-6-(4-methylpent-3-enyl)bicyclo[3.1.1]hept-2-ene; chemical formula: C 15H 24; exact mass: 

204.19; molecular weight: 204.35, m/z: 204.19 (100.0%), 205.19 (16.5%), 206.19 (1.2%); elemental analysis: C, 88.16; 

H, 11.84 

1.71 

1.71 

H 

5.20 

2.62 

2.04;1.79 

1.96 

1.25 

1.71 

1.97 

1.16 

H 5.37 

2.04;1.79 

25.6 

131.3 

19.6 

126.8 

46.8 

22.6 

31.6 

α-Bisabolene—(Z)-1-methyl-4-(6-methylhept-5-en-2-ylidene)cyclohex-1-ene; chemical formula: C15H24; exact mass: 


H, 11.84 

1.71 

17.4 

1.71 

2.00 

H 

1.71 

5.20 

2.00 

2.63 

2.00 

H 

5.21 

2.00 

1.71 

33.6 

26.7 

126.5 

30.5 

123.5 

40.3 

125.0 

132.0 

19.6 25.6 

β-Bisabolene—1-methyl-4-(6-methylhepta-1,5-dien-2-yl)cyclohex-1-ene; chemical formula: C15H24; exact mass: 204.19; 


1.71 

H 

1.71 

2.00 

2.00 

2.33 

1.77;1.52 

2.01;1.91 

4.88 

4.63 H 

106.7 

35.6 

28.4 

40.2 

153.5 

31.0 

H 

5.20 

2.09;1.84 

H 

5.37 

1.71 

26.7 

135.7 

28.4 

120.5 

31.4 

123.5 

123.3 

132.0 

19.6 25.6 

21.2 

43.5 

39.1 

31.7 

23.1 

132.1 

133.9 

23.2 

23.1 

123.3 

30.6




order) 

Bisabolol—(2S)-6-methyl-2-(4-methylcyclohex-3-enyl)hept-5-en-2-ol; chemical formula: C 15H 26O; exact mass: 222.2; 

molecular weight: 222.37, m/z: 222.20 (100.0%), 223.20 (16.6%), 224.21 (1.3%); elemental analysis: C, 81.02; H, 11.79; 

O, 7.20 

1.71 

1.71 

1.96 

5.20 

H 

1.31 4.64 

OH 

1.44 

1.74;1.49 

1.71 

2.01;1.91 

2.04;1.79 

H 

5.37 

1.71 

40.3 

18.5 

25.6 

OH 

19.4 

44.4 

77.2 

24.4 

126.8 

131.3 

19.6 25.6 

α-Butenol—(5R,Z)-2,10,10-trimethyl-6-methylenebicyclo[7.2.0]undec-2-en-5-ol; chemical formula: C 15H 24O; exact 

mass: 220.18; molecular weight: 220.35, m/z: 220.18 (100.0%), 221.19 (16.5%), 222.19 (1.5%); elemental analysis: C, 

81.76; H, 10.98; O, 7.26 

2.28;2.03 

H 

5.20 

5.01 H 

4.14 OH H 

4.96 

3.94 

2.63 

2.00;1.75 

1.71 

1.11 

2.01;1.91 

1.96 

1.41;1.16 

1.11 

34.1 

124.6 

76.3 

144.4 

44.8 

141.8 

40.3 

21.2 

27.7 

β-Butenol—(Z)-6,10,10-trimethyl-2-methylenebicyclo[7.2.0]undec-5-en-3-ol; chemical formula: C 15H 24O; exact mass: 


H, 10.98; O, 7.26 

2.28;2.03 

HO 

4.14 

3.94 

5.20 

H 

2.63 

1.71 

2.00;1.75 

H 1.11 

4.96 H 

5.01 

2.01;1.91 

1.96 

1.41;1.16 

1.11 

HO 

40.1 

OH 

124.6 

123.3 

109.8 

135.1 

74.1 42.3 

154.8 

40.6 

109.8 

27.7 

23.4 

31.2 

31.2 

133.9 

53.7 

33.9 

39.7 

23.1 

27.2 

27.7 

54.0 

33.9 

26.9 

27.7 





order) 

Calamenene—8-isopropyl-2,5-dimethyl-1,2,3,4-tetrahydronaphthalene; chemical formula: C15H22; exact mass: 202.17; 


2.33 

22.4 

6.65 

2.90;2.80 

1.68;1.43 

6.68 

1.77 

2.93;2.68 1.06 

3.12 

1.29 1.29 

132.9 

125.7 

136.6 

30.8 

32.9 

123.0 

142.1 133.9 

41.2 

34.4 

23.6 23.6 

29.7 

20.3 

α-Cadinene—1-isopropyl-4,7-dimethyl-1,2,4a,5,6,8a-hexahydronaphthalene; chemical formula: C 15H 24; exact mass: 


H, 11.84 

5.37 H 

1.71 

2.04;1.79 1.66 

1.98 

1.77;1.52 

2.01;1.91 

2.31 

1.82 

1.01 1.01 

H 

5.37 

1.71 

123.3 

28.5 

135.7 26.2 

51.3 

30.0 

21.3 

41.4 36.2 

124.2 

21.5 21.5 

β-Cadinene—(1S)-1-isopropyl-7-methyl-4-methylene-1,2,3,4,4a,5,6,8a-octahydronaphthalene; chemical formula: 

C 15H 24; exact mass: 204.19; molecular weight: 204.35, m/z: 204.19 (100.0%), 205.19 (16.5%), 206.19 (1.2%); elemental 

analysis: C, 88.16; H, 11.84 

4.63 H 

2.01;1.91 

1.41;1.16 

1.01 

1.82 

2.32 

1.49 

1.97 

1.01 

H 4.88 

1.77;1.52 

H 5.37 

2.01;1.91 

1.71 

109.1 

48.5 

124.2 

31.3 

133.9 

23.4 

52.2 

26.2 

36.1 148.0 31.3 

30.5 51.2 

30.0 

21.4 21.4 

133.9 

23.4




order) 

γ-Cadinene—(1S)-1-isopropyl-4,7-dimethyl-1,2,3,5,6,8a-hexahydronaphthalene; chemical formula: C15H24; exact mass: 


H, 11.84 

1.71 

17.3 

2.01;1.91 

1.74;1.49 1.66 

2.05;1.95 

2.63 

H 5.21 

1.82 

1.01 1.01 

2.01;1.99 

1.71 

31.1 

126.7 

23.5 45.2 

26.2 

129.7 

44.8 

30.0 

21.5 21.5 

γ-Cadinol—(1S,4R)-4-isopropyl-1,6-dimethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1-ol; chemical formula: C15H26O; exact mass: 222.2; molecular weight: 222.37, m/z: 222.20 (100.0%), 223.20 (16.6%), 224.21 (1.3%); elemental analysis: 

C, 81.02; H, 11.79; O, 7.20 

1.31 

OH 

1.67;1.42 

1.74;1.49 

1.53 

2.01;1.91 

4.64 

25.5 

OH 

40.2 

76.2 

17.2 

56.1 

31.5 

1.52;1.27 1.45 

2.10 

H 5.37 

1.82 

1.01 1.01 

1.71 

20.3 51.9 

125.1 

35.4 

29.9 

21.4 21.4 

β-Caryophyllene—(Z)-4,11,11-trimethyl-8-methylenebicyclo[7.2.0]undec-4-ene; chemical formula: C 15H 24; exact mass: 


H, 11.84 

1.71 

2.01;1.91 

1.41;1.16 

1.11 

5.20 

H 

1.96 2.63 

1.11 

2.00;1.75 

2.01;1.99 

2.05;1.95 

4.63 

H 

H 

4.88 

23.4 

33.7 

26.9 

27.7 

135.1 

33.9 

124.6 

124.2 

53.7 48.5 

149.9 

27.7 

40.3 

27.8 

34.9 

32.0 

130.6 

133.9 

23.5 

23.4 

109.8 





order) 

β-Caryophyllene alcohol—(E)-4,11,11-trimethyl-8-methylenebicyclo[7.2.0]undec-4-en-5-ol; chemical formula: 

C 15H 24O; exact mass: 220.18; molecular weight: 220.35, m/z: 220.18 (100.0%), 221.19 (16.5%), 222.19 (1.5%); 


1.71 

2.01;1.91 

1.41;1.16 

1.11 

16.77 

OH 

1.96 2.63 

1.11 

2.01;1.99 

2.05;1.95 

H 

2.00;1.75 4.63 

H 

4.88 

13.2 

29.5 

27.2 

27.7 

173.7 

106.5 

33.9 

149.9 

53.7 48.5 

β-Caryophyllene oxide—chemical formula: C 15H 24O; exact mass: 220.18; molecular weight: 220.35, m/z: 220.18 

(100.0%), 221.19 (16.5%), 222.19 (1.5%); elemental analysis: C, 81.76; H, 10.98; O, 7.26 

1.31 

1.50;1.25 

1.38;1.13 

1.11 

2.51 

O 

1.96 2.63 

1.11 

1.59;1.34 

2.01;1.91 

4.88 

H 

H 

2.00;1.75 

4.63 

39.0 

27.4 

27.7 

OH 

64.9 

60.7 

33.8 

40.3 

153.2 

53.3 48.4 

α-Chamigrene—1,5,5,9-tetramethylspiro[5.5]undeca-1,8-diene; chemical formula: C 15H 24; exact mass: 204.19; 


2.01;1.91 

1.70;1.45 

1.11 

5.37 

H 

1.71 

1.74;1.49 

2.01;1.91 

2.04;1.79 

1.11 

1.71 

H 

5.37 

21.0 

27.7 

22.5 

36.4 

23.4 

123.3 

O 

27.7 

38.6 47.8 

30.3 

40.3 

19.4 

32.2 

29.5 

144.0 

37.1 

23.4 

123.3 

28.7 

33.2 

109.8 

109.1 

29.4 

133.9 

23.1




order) 

α-Cubebene—chemical formula: C 15H 24; exact mass: 204.19; molecular weight: 204.35, m/z: 204.19 (100.0%), 205.19 


1.71 

5.38 

H 

2.33;2.08 

0.87 

1.06 

1.59 

1.44 

1.41 

1.82 

1.01 1.01 

1.52;1.27 

1.52;1.27 

20.9 

123.8 

44.4 

142.6 39.5 

22.6 

16.1 

39.9 

28.0 

45.7 

29.9 

29.3 

26.5 

21.3 21.3 

α-Cuparene—(R)-1-methyl-4-(1,2,2-trimethylcyclopentyl)cyclohexa-1,3-diene; chemical formula: C 15H 24; exact mass: 


H, 11.84 

1.56;1.46 

1.55;1.30 

1.26 

1.60;1.35 2.15 

1.11 

1.11 

H 

5.68 

2.15 

H 

5.68 

1.71 

21.1 

41.5 

36.1 

48.0 

22.7 

20.2 24.8 

155.2 

57.8 

32.0 

118.6 120.1 

22.7 

145.3 

23.2 

Dihydro-alpha-copaene-8-ol—chemical formula: C 15H 26O; exact mass: 222.2; molecular weight: 222.37, m/z: 222.20 

(100.0%), 223.20 (16.6%), 224.21 (1.3%); elemental analysis: C, 81.02; H, 11.79; O, 7.20 

H 5.30 

H 1.64 

HO 

4.81 

1.14 

H 

1.01 

3 

2 

1.16 

5 1.52;1.27 

4 1.40 10 

9 1.52;1.27 

H 1.46 

1.60 

1 6 8 

7 1.06 

H 1.59 

1.82 

H 1.48 

1.01 

48.5 

23.2 

37.5 5 

4 48.2 

70.3 

HO 

2 1 

51.6 

23.6 

31.9 

6 

56.7 

7 

21.6 

3 

21.6 

26.4 

10 

9 

34.2 

33.4 

8 

19.1 





order) 

β-Elemene—(1R,2S,4R)-1-methyl-2,4-di(prop-1-en-2-yl)-1-vinylcyclohexane; chemical formula: C 15H 24; exact mass: 


H, 11.84 

4.88 

H 

H 

5.79 

1.71 

H 

4.66 

4.95 

H 

1.26 

1.52;1.27 

2.14 2.12 

1.57;1.32 

H 4.67 

1.57;1.32 H 4.67 

1.71 

H 4.66 

115.7 

146.3 

22.1 

147.7 

110.6 

25.5 

40.3 

γ-Elemene—(S)-1-methyl-2,4-di(propan-2-ylidene)-1-vinylcyclohexane; chemical formula: C 15H 24; exact mass: 204.19; 


4.92 H 

5.71 H 

1.71 

H 

1.36 

1.46;1.21 

4.95 

1.71 

2.68;2.58 

2.01;1.91 

1.71 

1.71 

20.2 

121.5 

40.0 

57.1 

112.6 28.0 

145.6 

20.2 

30.6 

45.7 

44.9 

33.4 

26.6 

26.6 

147.7 

132.5 129.1 

β-Eudesmol—2-((4aR)-4a-methyl-8-methylenedecahydronaphthalene-2-yl)propan-2-ol; chemical formula: C 15H 26O; 

exact mass: 222.2; molecular weight: 222.37, m/z: 222.20 (100.0%), 223.20 (16.6%), 224.21 (1.3%); elemental analysis: 

C, 81.02; H, 11.79; O, 7.20 

1.38;1.28 

2.01;1.91 

H 

4.66 

1.16 

1.34;1.09 1.49;1.24 

H 

4.67 

2.10 1.50 

1.52;1.27 

1.52;1.27 

1.26 

OH 

1.26 4.64 

23.9 

38.2 148.0 

23.0 

39.4 39.4 

109.1 

34.2 

57.0 

23.0 

21.4 

28.6 

20.3 

19.5 

110.6 

124.6 

19.5 

46.8 27.6 

73.5 

OH 

27.6




order) 

α-Farnesene—(3Z,6E)-3,7,11-trimethyldodeca-1,3,6,10-tetraene; chemical formula: C 15H 24; exact mass: 204.19; 


5.26 

H 

2.63 

2.00 

2.00 

1.71 

H 5.21 

1.71 

H 5.20 

1.71 1.71 

H 5.16 

H 6.25 

H 

5.02 

39.8 

26.4 

136.5 

17.6 

123.5 

121.8 

24.7 

138.3 

116.1 

19.6 

132.0 

25.6 

β-Farnesene—(E)-7,11-dimethyl-3-methylenedodeca-1,6,10-triene; chemical formula: C 15H 24; exact mass: 204.19; 


4.80 

H 

H 

4.88 

6.25 

H 

2.00 

2.00 

2.00 

5.02 

H 

2.00 

H 

5.16 

5.20 

H 

1.71 

H 

5.20 

1.71 1.71 

39.7 

26.4 

135.7 

17.5 

123.5 

122.7 

26.8 

138.3 

116.1 

132.0 

19.6 25.6 

131.0 

135.1 

38.2 

22.4 

143.9 

110.4 





order) 

Germacrene D—(1E,6E)-8-isopropyl-1-methyl-5-methylenecyclodeca-1,6-diene; chemical formula: C 15H; exact mass: 


H, 11.84 

2.00 

2.00 

H 

4.88 

5.20 

H 

2.01;1.91 

H 4.80 

1.71 

H 

6.03 H 5.61 

1.46;1.21 

2.15 

1.86 

1.01 

1.01 

126.2 

39.4 

140.6 

30.5 

125.1 55.0 

32.4 21.1 

26.1 

37.7 17.4 

148.5 

136.4 

110.4 21.1 

α-Himachalene—(4aS,9aR)-3,5,5-trimethyl-9-methylene-2,4a,5,6,7,8,9,9a-octahydro-1H-benzo[7]annulene; chemical 



2.01;1.91 

1.71 

4.63 H 

2.32 H 

1.77;1.52 

H 

H 1.96 

1.11 

5.37 

H 4.88 

2.01;1.91 

1.38;1.28 

1.34;1.09 

1.11 

23.4 

31.3 

133.9 

109.1 

26.8 

H 

49.7 

148.7 

38.8 

46.9 

23.5 

124.2 

37.2 

45.4 

H 

25.9 25.9 

α-Humulene—(1Z,4Z,8Z)-2,6,6,9-tetramethylcycloundeca-1,4,8-triene; chemical formula: C 15H 24; exact mass: 204.19; 


1.71 

2.00 

5.20 H 

2.00 

1.92 

1.21 

H 5.15 

1.71 

2.63 

H 5.37 

1.21 

H 5.43 

23.5 

36.6 

124.7 

24.5 

131.9 

124.8 

37.5 

42.0 

30.2 

133.1 

23.5 

39.0 

123.3 

144.7 

30.2




order) 

β-Humulene—(1Z,5Z)-1,4,4-trimethyl-8-methylenecycloundeca-1,5-diene; chemical formula: C 15H 24; exact mass: 


H, 11.84 

1.71 

5.20 H 

1.96 

1.37 

1.92 

1.21 

1.96 

H 4.70 

2.63 

H 4.67 

H 5.37 

1.21 

H 5.43 

23.4 

38.4 

124.1 

25.4 

132.6 

42.5 

139.5 

37.5 

42.0 

Longifolene—chemical formula: C 15H 24; exact mass: 204.19; molecular weight: 204.35, m/z: 204.19 (100.0%), 205.19 


1.34;1.24 

1.34;1.09 

1.38;1.13 

1.11 

1.26 

1.51 

1.50 

H 4.88 

1.11 

1.60;1.35 

2.18 

H 4.63 

1.63;1.38 

30.2 

165.0 

37.6 

33.0 

57.0 

20.0 

62.2 

43.4 32.5 

α-Murrolene—1-isopropyl-4,7-dimethyl-1,2,4a,5,6,8a-hexahydronaphthalene; chemical formula: C 15H 24; exact mass: 


H, 11.84 

5.37 H 

2.04;1.79 

1.71 

1.66 

1.77;1.52 

2.32 

2.01;1.91 

1.97 

1.82 

H 

1.01 1.01 

5.37 

1.71 

123.3 

26.1 

21.3 

28.5 41.4 

22.9 

135.7 

51.3 

30.0 

36.2 

21.5 21.5 

109.1 

26.1 

26.2 

124.2 

30.2 

48.1 

31.3 

110.7 

43.0 

123.3 

144.7 

30.2 

32.9 

133.9 

23.4


2.4 chemIstry and uses oF Cymbopogon essentIal oIls 

The trading of essential oils has always been dependent on the knowledge imparted regarding its 

quality. The components present in it and the odor value provided to it because of several physical 

and chemical parameters are of immense value. These have been important criteria since ancient 

and medieval times. Chemists had to develop methods of analysis of oils and determine their 

chemical composition because of possibilities of adulterations of cheaper essential oils with highly 

priced ones. Prior to the advent of gas liquid chromatography (GLC) (Ille 1986), chemists had to 

rely entirely on chemical analysis, but GLC analysis might be the most important factor in this 

regard, and of possible help. During the last two decades, the methodology has improved manyfold. 

Consequently, the data regarding major and minor constituents found in essential oils has also 

multiplied and helped in evaluating the quality of the oils besides providing information on the 

constituents that could be isolated and used in pure form. 

2.4.1 le M o n G r a s s oils 

Lemongrass oil is distilled from two morphologically different species of lemongrass, C. flexuosus 

(common name: East Indian lemongrass) and C. citratus (common name: West Indian lemongrass). 

The chemical composition of these oils is very similar, though the percentage of citral and other 

major monoterpenes vary to some extent. A high yield of citral has been reported in C. pendulus 

(common name: North Indian lemongrass), which is another wild species and under limited cultivation. 

It has also been a major commercial source of lemongrass oil. 

2.4.1.1 Cymbopogon flexuosus 

The East Indian lemongrass (C. flexuosus (Steud.) Wats.) oil is indigenous to South India, found 

in the Malabar and Cochin regions, and in the Malay Peninsula. A product of C. flexuosus comes 

from Ceylon, Myanmar, and adjacent countries, as well as from Mexico and the West Indies. It is 

commonly called Malabar lemongrass oil. The major and trace constituents reported by various 

workers have been tabulated in Table 2.1. In one of the reports, Nath et al. (1994) have identified 

25 components after examining the essential oil. Geraniol, citronellol, neral, and geranial have 

been reported as the major components. Neral is also referred in the books and literature as citralcis, 

citral-a, α-citral, (Z)-3,7-dimethylocta-2,6-dienal or citral-(Z). Similarly, geranial has also been 

termed as citral-trans, Citral-b, β-citral, (E)-3,7-dimethylocta-2,6-dienal or citral-(E). During several 

studies conducted in the last few years (Bhattacharya et al. 1997; Boelens 1994; Cherian et al. 

1993; Choudhary and Kaul 1979; Kulkarni et al. 1997; Kuriakose 1995; Mathela et al. 1996; Nair 

et al. 1984; Patra and Dutta 1986; Rao et al. 1995), many chemotypes/cultivars/variants have been 

reported. Rao et al. (1992) have identified α-bisabolol and methyl isoeugenol as major components 

in a chemotype. It has also been found that the quality of the herb deteriorates on storage of the herb 

and also affects oil quality (Singh et al. 1994). In a GC-MS analysis of the essential oil, 32 constituents 

were identified (Taskinen et al. 1983). Kulkarni et al. (1997) reported a variant resembling citronella 

that contained citronellol (9.5%), citronellal (6%), citronellyl acetate (11.2%), geraniol (11.1%), 

and geranyl acetate (25.9%), along with 20 other constituents. The profiles of essential oils from 

five C. flexuosus cultivars (OD-19, Pragati, Cauvery, SHK-7, and GRL-l); one C. pendulus cultivar 

(Praman); and one hybrid C. khasianus × C. pendulus cultivar (CKP-25) have been examined on 

the GLC capillary column. Besides cultivated species (Atal and Bradu 1976a), a few wild-growing 

strains of the species have also been investigated and designated as RRL-14 and RRL-59, which 

contained geranial (40%) and methyl isoeugenol (20%) as the major constituents of the essential oil 

pool. The results revealed that cultivar GRL-1 (Patra et al. 1990) is different from other cultivars 

because of the presence of a high amount of geraniol (80.2%) and relatively higher concentration 

of myrcene (3.97%) and geranyl acetate (4.6%) (Patra et al. 1997). C. sikkimensis, which was a new 

variety of C. flexuosus, revealed the presence of methyl isoeugenol (20.5%), methyl eugenol (23%),


and d-limonene (16.5%) as major constituents. The hybrid lemongrass CKP-25 differed from other 

citral-rich varieties with respect to a number of minor compounds (Bhattacharya et al. 1997). 

The oil of lemongrass is widely used in soaps and detergents (Bhattacharya 1970; Guenther 

1950; Opdyke 1976). Citral (a mixture of geranial and neral) is the major component of the oil and 

is isolated in bulk to be used in flavors, cosmetics, and perfumes. Ionones is another group of very 

important synthetic aromatics that possesses a strong and lasting odor. They are synthesized from 

citral and are further used in the manufacture of synthetic vitamin A. 

The antifungal, antibacterial, and antioxidant properties of lemongrass oil has been widely utilized 

(Alam et al. 1994; Gyane 1976; Mehmood et al. 1997; Ramdan et al. 1972a, 1972b; Rao et al. 

1971; Shadab-Qamar et al. 1992; Singh et al. 1978; Wannissorn et al. 1996). Allergic contact dermatitis 

has been reported with the oil (Selvag et al. 1995). Some other uses have been reported as preservative 

(Arora and Pandey 1977) and in inhibition of sensitization reactions (Opdyke 1976). The 

leftover residue from lemongrass leaves has been successfully utilized as a source of raw material 

for cellulose pulp and paper production (Ciaramello et al. 1972; Ramirez et al. 1977; Siddique-Ullah 

et al. 1979). The other important use of the oil has been in the preparation of an insect-repellent 

complex (Anonymous 1973), which has been tested for insect repellent/attractant and nematicidal 

activities (Ansari and Razdan 1995). 

The cultivation, essential oil characteristics, chemical constituents, and uses (culinary, antibacterial, 

medicinal, aromatic, and others) of lemongrass, and the lemongrass industry in India have been 

discussed at length in an article by Gupta and Jain (1978) Ansari et al. (1996) in earlier publications. 

Data have been tabulated on the differences between C. flexuosus and C. citratus oils in terms 

of their physicochemical properties, the effects of drying the herbage in sunlight for up to 5 days 

before distillation on oil yields, and export of lemongrass oil from India during 2002–2007 have 

also been discussed in this book. Effect on quality of citral content on preservation of lemongrass 

oil has also been worked out (Kurian et al. 1984). 

2.4.1.2 Cymbopogon citratus 

The West Indian lemongrass oil (C. citratus (D.C.) Stapf) is rated inferior in quality to that of 

the East Indian type because of its low citral content. However, it attained importance after 

World War II when the latter was difficult to obtain. Its major constituents are listed in Table 2.1, 

but it differs from the East Indian type by the occurrence of substantial quantities of myrcene 

(12%–15%). The myrcene may undergo diene-condensation and polymerization on aging, and hence 

loses its solubility in 70% alcohol. The C. citratus is an important crop in Ethiopia, and its analysis 

has shown geraniol (40%), geranial and neral (13%–15%), and α-oxobisabolene (12%) as major 

constituents, which are different from usual West Indian lemongrass oil (Abegaz et al. 1983). The 

hydrodistilled essential oil from the leaves of C. citratus Stapf grown in Zambia was analyzed by 

GC and GC-MS. Sixteen compounds representing 93.4% of the oil were identified, of which citraltrans 

(39.0%), citral-cis (29.4%), and myrcene (18.0%) were the major components. Small amounts 

of geraniol (1.7%) and linalol (1.3%) were also detected (Esmort et al. 1998). The composition of 

the essential oil of the leaves growing on the campus of Lagos State University was determined 

by the use of GC and GC-MS. The oil gave 27 peaks, amounting to 98% of the total oil. Twentythree 

constituents amounting to 97.3% of the total oil were identified. The main constituents were 

geranial (33.7%), neral (26.5%), and myrcene (25.3%). Small amounts of neomenthol (3.3%), linalyl 

acetate (2.3%), Z-β-ocimene (1.0%), and E-β-ocimene were also detected (Adeleke et al. 2001). In 

one of the reports, citral (69.39%) has been cited as a major component along with other minor components, 

such as caryophyllene, citronellol, geraniol, α- and β-pinene, ethyl laurate, 1-8-cineole, 

limonene, phellandrene methyl heptenone, linalool, menthol, myrcene, terpineol, and citronellol 

(Torres and Ragadio 1992, 1996). 

In one of the studies, a method was developed to validate a HPLC procedure for the quantitative 

determination of citral in C. citratus volatile oil. The HPLC assay was performed using a 

Spherisorb ® CN column (250 mm × 4.6 mm, 5 μm), an n-hexane:ethanol (85:15) mobile phase,


and a UV detector (set at 233 nm). The following parameters were evaluated: linearity, precision, 

accuracy, specificity, quantification, and detection limits. The method showed linearity in the range 

of 10.0–30.0 μg mL −1 . Precision and accuracy were determined at the concentration of 20 μg mL −1 . 

The concentration of citral in C. citratus volatile oil obtained with this assay was 75%. The HPLC 

method developed in this study showed an excellent performance (linearity, precision, accuracy, 

and specificity), and can be applied to assay citral in volatile oil (Rauber et al. 2005). A total of 

34 compounds were identified in Moroccan C. citratus oil, constituting about 89% of the total oil, 

with geraniol and neral (39.8% and 32%, respectively) as major constituents. The oil yield was drastically 

reduced under rust disease indices reduction (Baruah et al. 1995). A reduction in geraniol 

content in contrast to an increase in neral and myrcene was observed. The plant extract yielded 

tanins in herbal tea (Blake et al. 1993), with cymbopogene, cymbopogonol, triacontanol, alkaloid, 

and saponin (Ansari et al. 1996) being identified. The presence of alkaloids was reported; however, 

it needs further confirmation. The crop growing in Nagcorlan and Laguna was reported to contain 

93.74% citral (citral-a, citral-b, and others in the ratio of 61:33:6) (Torres 1993). 

This oil has also been reported to be antimicrobial (Chalchat et al. 1997; Handique and Singh 

1990; Kokate and Verma 1971; Moris et al. 1979; Orafidiya 1993; Syeed et al. 1990; Yadav and 

Dubey 1994) and insecticidal (Sukari et al. 1992), insect repellant (Ansari and Razdan 1995), and 

found to have cytotoxic properties apart from its usual uses in perfumery, food flavor, and pharmaceutical 

industries (Guenther 1950; Opdyke 1976). C. citratus oil has also been tested for anticarcinogenic 

activities (Dubey et al. 1997; Zheng et al. 1993). Citral-a and citral-b have been shown to 

possess antibacterial activity in the oil (Onawunmi et al. 1984). 

In another study, the antibacterial properties of the essential oil have been recorded. These activities 

are shown in two of the three main components of the oil identified through CG and MS methods. 

Whereas the α-citral (geranial) and β-citral (neral) components individually elicit antibacterial 

action on Gram-negative and Gram-positive organisms, the third component, myrcene, did not show 

observable antibacterial activity on its own. However, myrcene provided enhanced activities when 

mixed with either of the other two main components identified (Grace et al. 1984). C. citratus is 

one of the most commonly used plants in Brazilian folk medicine for the treatment of nervous and 

gastrointestinal disturbances. It is also used in many other places to treat feverish conditions. The 

usual way to use it is by ingesting an infusion made by pouring boiling water on fresh or dried leaves 

(which is called “abafado” in Portuguese). Abafados obtained from lemongrass harvested in three 

different areas of Brazil (Ceará, Minas Gerais, and São Paulo states) were tested on rats and mice 

in an attempt to add experimental confirmation of its popular medicinal use. Citral, the main constituent 

of the essential oil in Brazilian lemongrass, was also studied for comparison. Oral doses of 

abafados up to 40 times (C 40) larger than the corresponding dosage taken by humans, or 200 mg/kg 

of citral, were unable to reduce the body temperature of normal rats and/or rats made hyperthermic 

by previous administration of pyrogen. However, both compounds acted when injected via the intraperitoneal 

route. Oral administration of doses C 20–C 100 of abafados and 200 mg/kg of citral did not 

change the intestinal transit of a charcoal meal in mice; neither did it decrease the defecation scores 

of rats in an open-field arena. Again, via the intraperitoneal route, both compounds were active. The 

possible central nervous system depressant effect of abafados was investigated by using batteries of 

12 tests designed to detect general depressant, hypnotic, neuroleptic, anticonvulsant, and anxiolytic 

effects. In all the tests employed, oral doses of abafados up to C 208 or citral up to 200 mg/kg were 

without effect. Only in a few instances did intraperitoneal doses demonstrate effects. These data 

do no lend support to the popular oral therapeutic use of lemongrass to treat nervous and intestinal 

ailments and feverish conditions (Carlini et al. 1986). Tea obtained from leaves of C. citratus (D.C.) 

Stapf is used for its anxiolytic, hypnotic, and anticonvulsant properties in Brazilian folk medicine. 

Essential oil (EO) from fresh leaves was obtained by hydrodistillation and orally administered to 

Swiss male mice 30 min before experimental procedures. EO at 0.5 or 1.0 g/kg was evaluated for 

sedative/hypnotic activity through pentobarbital sleeping time, for anxiolytic activity by elevated 

plus maze and light/dark box procedures, and for anticonvulsant activity through seizures induced


by pentylenetetrazole and maximal electroshock. EO was effective in increasing the sleeping time, 

percentage of entries, and time spent in the open arms of the elevated plus maze as well as the 

time spent in the light compartment of the light/dark box. In addition, EO delayed clonic seizures 

induced by pentylenetetrazole and blocked tonic extensions induced by maximal electroshock, indicating 

the elevation of the seizure threshold and/or blockage of seizure spread. These effects were 

observed in the absence of motor impairment evaluated on the rota-rod and open-field tests. The 

results were in accord with the ethnopharmacological use of C. citratus, and, after complementary 

toxicological studies, it can support investigations assessing their use as an anxiolytic, sedative, or 

anticonvulsive agent (Blanco et al. 2007). 

Studies were conducted to investigate the hypoglycemic and hypolipidemic effects of the single, 

daily oral dosing of 125–500 mg/kg of fresh leaf aqueous extract of C. citratus Stapf in normal, 

male Wistar rats for 42 days. The average weights of rats per group were taken at 2-week intervals 

for 42 days. On day 43, blood samples from the rats were collected for fasting plasma glucose 

(FPG), total cholesterol, triglycerides, low-density lipoproteins (LDL-c), very low-density lipoprotein 

(VLDL-c), and high-density lipoprotein (HDL-c) assays through cardiac puncture under halothane 

anesthesia. Acute oral dose toxicity study of C. citratus was also conducted using the limit 

dose test of the Up and Down Procedure statistical program (AOT425StatPgm, Version 1.0) at a 

dose of 5000 mg/kg body weight/oral route. These results showed C. citrates to lower the FPG and 

lipid parameters dose dependently (p < 0.05) while raising the plasma HDL-c level (p < 0.05) in the 

same dose-related fashion but with no effect on the plasma triglycerides level (p > 0.05). The results 

of acute oral toxicity showed CCi to be of low toxicity and, as such, could be considered relatively 

safe on acute exposure, thus confirming its folkloric use and safety in suspected Type 2 diabetic 

patients (Adeneye and Agbaje 2007). 

2.4.1.3 Cymbopogon pendulus 

The North Indian lemongrass oil (C. pendulus (Nees ex Steud.) Wats.) occurs in wild areas of northern 

India such as Saharanpur (in the state of Uttar Pradesh) (Atal and Bradu 1976a; Muthuswami 

and Sayed 1980). The major and minor constituents are listed in Table 2.1. This is also a major 

source of lemongrass oil that is used in perfumery as much as the East Indian variety. In one of 

the reports, elemicin (53.7%) content was found to be very high in the essential oil obtained from 

this plant. It is noteworthy that it is the starting material for the synthesis of the antimalarial drug 

trimethoxyprim. (Z)-asarone (5.3%) is another valuable component of this oil, which is used as an 

antiallergic compound (Shahi et al. 1997). 

2.4.2 Ci t r o n e l l a oils 

C. winterianus and C. nardus are cultivated on a large scale, and these are closely related to each 

other in various aspects. Both species are distinguished morphologically by the shape and length of 

their leaves. The chemical composition of the essential oil obtained from them also differs considerably 

(Lawrence 1991; Wijesekara et al. 1973). 

2.4.2.1 Cymbopogon winterianus 

The Java citronella (C. winterianus Jowitt) is grown mainly in Java, Haiti, Honduras, Taiwan, 

Guatemala, and China, and is highly priced in comparison to the Ceylon type (see the following 

text) because its oil contains higher percentages of monoterpene alcohols and their esters. These 

are listed in Table 2.1. This oil is also known as Mahapengiri oil. The trace constituents identified 

from the essential oil include geranyl formate, borneol, farnesol, cadinene, l-cadinol, l-camphene, 

1-carvone, citral, citronellyl butyrate, cymbopol, dipentene, eugenol, l-limonene, linalool, methyl 

heptenone, methyl eugenol, α-pinene, sesquicitronellene, terpinene, terpinen-4-1, and thujyl alcohol. 

Conventional and nonconventional techniques have been applied while carrying research on 

these crops (Chauhan et al. 1976) because of their diversity and immense usefulness. The climatic


conditions and time of harvesting have been important factors in determining the chemical profile 

of the citronella oil (Singh et al. 1996), and this has been discussed in another chapter in this book. 

The pattern of accumulation of monoterpenes and effect of storage of herb prior to distillation 

have been reported (Singh et al. 1994, 1996). Soulari and Fanghaenel (1971) made a detailed study 

of essential oil of C. winterianus produced in Cuba. An improved variety of Java citronella was 

released by Ganguly et al. (1979). 

The hydrodistilled essential oil from the aerial parts of C. winterianus Jowitt, cultivated in 

Southern Brazil, was analyzed by GC-MS. Thirty-one components, representing 96% of the oil, 

were characterized. Enantiomeric ratios of limonene, linalool, citronellal, and β-citronellol were 

obtained by multidimensional gas chromatography, using a developmental model set up with two 

GC ovens. The enantiomeric distributions are discussed as indicators of the origin authenticity and 

quality of this oil (Lorenzo et al. 2000). 

Java citronella oil is one of the most important essential oils because of the high content of 

citronellal and is mainly used for the isolation of citronellal, which is converted into citronellol. 

Citronellol is further converted into citronellol esters, hydroxy citronellal, and synthetic menthol 

(Dev Kumar et al. 1977). Java citronella oil is usually employed in the scenting of soaps and all 

kinds of technical preparations as well as for the extraction of aromatic isolates. 

The essential oil steam-distilled from C. winterianus (Java citronella) of Cuban origin was analyzed 

by GC and GC-MS. Thirty-six compounds were identified, of which citronellal (25.04%), 

citronellol (15.69%), and geraniol (16.85%) were the major constituents (Pino et al. 1996). Using 

enantioselective multidimensional chromatography (enantio-MDGC) and the column combination 

polyethylene glycol/heptakis (2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrinin OV 

1701-vi, the chiral monoterpenoids cis/trans-rose oxides, linalol [linalool], citronellol, and terpinen- 

4-ol were stereoanalyzed simultaneously. The method was applied to chirality evaluation of these 

compounds in commercial and authentic Java (C. winterianus) and Ceylon (C. nardus) citronella 

oils. The enantiomeric distributions are discussed with reference to their uses as indicators of the 

authenticity of these essential oils (Kreis et al. 1994). 

2.4.2.2 Cymbopogon nardus 

Citronella oil is derived from C. nardus (L.) Rendle and is also called “Lanabatu oil.” The grass 

is mostly cultivated in Sri Lanka, and hence the oil obtained from it is known as Ceylon citronella 

oil. The main constituents of this oil have been presented in Table 2.1. The presence of phenolic 

derivatives (methyl eugenol and methyl isoeugenol) is the most significant difference between the 

Ceylon-type and Java-type oils. The wild varieties of citronella growing in Sri Lanka contain phenyl 

propanoids in abundance, whereas phenyl propanoids are present in traces in the Java-type 

oil, and this is the significant difference between them. The presence of elemol in the Ceylon-type 

has been suggested to be formed as an artifact. Wijesekara et al. (1973) isolated hedycaryol, a 

thermolabile precursor, by cold percolation of the macerated fresh grass. In one of the reports it 

was shown that the oil contained large amounts of monoterpene hydrocarbons, whereas the Java 

variety (Mahapengiri) contained only small amounts, mainly limonene. Both types contained comparable 

amounts of geraniol, and the Java type had more quantities of citronellol and citronellal. 

In addition, the Ceylon type contained tricyclene, methyl eugenol, methyl isoeugenol, eugenol, and 

l-borneol. The GLC profiles enable the identification of the type of oil and the detection of kerosene 

as a possible adulterant. The variety that grows wild in Sri Lanka (Mana) was quite different 

from both cultivated types (Wijesekera et al. 1973). The steam-distilled volatile oil obtained from 

partially dried grass (citronella grass) C. nardus (Linn.) Rendle (Syn. Andropogon nardus Linn.), 

cultivated in the Nilgiri Hills at Ooty, India, was analyzed by capillary GC and GC-MS. The partially 

dried grass contained 35 components, out of which 29 constituents were completely identified 

and comprised 92.7% of the oil. The oil contains 16 monoterpenes (79.8%), nine sesquiterpenes 

(11.5%), and four nonterpenic compounds (1.4%). The prominent monoterpenes were citronellal 

(29.7%), geraniol (24.2%), γ-terpineol (9.2%), and cis-sabinene hydrate (3.8%). The predominant


sesquiterpenes were (E)-nerolidol (4.8%), β-caryophyllene (2.2%), and germacren-4-ol (1.5%) 

(Vijender and Mohammed 2002). 

A total of 36 compounds were identified in the steam-distilled essential oil of C. nardus collected 

from Zimbabwe in 1989. The major compound was trans-geraniol (29.47%), followed by its 

ester form geraniol formate (8.79%) (Moody et al. 1995). 

The Ceylon citronella oil was tested against Gram-positive bacteria and fungi, and it was 

found that, under in vitro conditions, the oil was as active as penicillin (Kokate and Verma 1971). 

C. winteri anus oil also finds use in providing scent and good smell to low-cost products such as 

soaps, sprays, disinfectants, polishes, and all kinds of technical preparations. Several products and 

formulations have been prepared using citronella oil (Chicopharma 1970; Kichiyoshi et al. 1981) for 

preventing thinner sniffing and slowing the release of the rapidly evaporating substances into the 

atmosphere. A number of patents have been filed on the uses of citronella oil. A patent describes the 

use of citronella grass after the distillation in papermaking and sulfate pulping (Bhaumik and Rao 

1978a, 1978b; Ciaramello et al. 1972). Another French patent by Tabakoff in 1969 and a Japanese 

publication by Fuji et al. in 1972 described the use of citronella oil in a composition that can be 

used with or without addition of water and does not corrode equipment or harm the hands. A joint 

Canadian and Indian Patent (Prasad and Jamwal 1971; Shaw 1971) described the use of citronella oil 

for the production of a formulation as mosquito repellent. Similarly, it was also found to be effective 

as housefly repellent (Osmani et al. 1972). 

2.4.3 Pa l M a r o s a a n d Gi n G e r G r a s s oils 

Palmarosa oil is obtained (Shylaraj and Thomas 1992) from the variety motia, which yields an oil 

of better quality having more geraniol and which is commercially much more important than the 

oil of gingergrass derived from the variety “sofia.” The oil obtained from variety sofia is sometimes 

used as an adulterant (Biaswara et al. 1976a, 1976b). The two important essential oils, palmarosa oil 

C. martinii (Roxb.) Wats. and gingergrass oil, are obtained from two of the most important grasses 

cultivated in India. The sofia variety has lower geraniol content. 

2.4.3.1 Cymbopogon martinii 

Palmarosa oil (C. martinii (Roxb.) Wats.), distilled from variety motia, has geraniol as the major 

component and is considered better in quality (Siddiqui et al. 1975, 1979). GC-MS analysis (Gaydou 

and Raudriamiharisoa 1987) of the hydrocarbons (4.75%) of the oil showed the presence of monoterpenes 

(45.9%), sesquiterpenes (52.2%), n-alkanes (1.6%), and unidentified compounds (0.4%). The 

main and trace constituents from the oil have been listed in Table 2.1. An interesting dihemiacetal 

bismonoterpenoid has been identified by Bottini et al. (1987). The x-ray diffraction method was used 

to establish its structure. Palmarosa oil is another that is extensively used more than any other oil in 

soaps, and it imparts a rose-like prominent and lasting odor (Guenther 1950; Opdyke 1974). This oil 

is also employed in the flavoring of tobacco and other mouth fresheners. There are several reports 

that the oil content increases by storing the herb prior to distillation (Singh et al. 1994). This has been 

discussed in another chapter by Aklandey in this book. Fungitoxic activity has also been reported 

from this oil (Singh et al. 1980) and, as in the case of the citronella crop, the leftover part after distillation 

of the plant is used in paper production (Ciaramello et al. 1972). The essential oil produced from 

the sofia variety of C. martinii Stapf is known as gingergrass oil. The major and minor constituents 

of the oil are listed in Table 2.1. The cis and trans forms of p-menth-2,8 diene-1-ol, p- menth1(7),8dien-2-ol, 

carveol, and piperitol, along with limonene (20%) and monoterpene alcohols, have been 

reported from the wild strain of C. martinii var. sofia growing in Kumaon hills (Mathela et al. 1988; 

Mathela and Pant 1988; Mathela et al. 1986). One new hemiacetal bismonoterpenoid compound 

cymbodi acetal was characterized in the oil of C. martinii (Bottini et al. 1987). The oil of gingergrass 

is used in low-cost perfume formulations and scenting of soaps and cosmetics.


The composition of the hydrocarbon fraction of the essential oil from C. martinii, which represents 

less than 5% of the oil, has been studied. Using well-established techniques, 11 monoterpenes 

(ca 46%), 28 sesquiterpenes (ca 52%), and 16 n-alkanes (ca 1.6%) have been identified. The 

major constituents are limonene, α-terpinene, myrcene, β-caryophyllene, α-humulene, and β- and 

δ-selinenes. The study of the n-alkanes of C. martinii revealed the presence of all members of the 

homologous series C 15–C 30 (Gaydou and Raudriamiharisoa 1986, 1987b). 

[2R-(2α,4αβ,5αβ,7α,9αβ,10αβ)]-Octahydro-2,7-bis(1-methylethenyl)5αH, 10αH-4α, 

9α-ethanodibenzo[b, e] [1,4]dioxin-5α,10α-diol (cymbodiacetal), isolated from the essential oil of 

C. martinii, was identified by means of x-ray diffraction of its 1:1 solvate with deuteriochloroform 

(Bottini et al. 1987). Only immature palmarosa C. martinii (Roxb.) Wats. var. motia inflorescence 

with unopened spikelets accumulated essential oil substantially. Geraniol and geranyl acetate together 

constituted about 90% of palmarosa oil. The proportion of geranyl acetate in the oil decreased significantly 

with a corresponding increase of geraniol during inflorescence development. An esterase 

enzyme activity, involved in the transformation of geranyl acetate to geraniol, was detected from 

the immature inflorescence using a GC procedure. The enzyme, termed as geranyl acetate-cleaving 

esterase (GAE), was found to be active in the alkaline pH range with the optimum at pH 8.5. The 

catalysis of geranyl acetate was linear up to 6 h, and after 24 h of incubation, 75% of the geranyl 

acetate incubated was hydrolyzed. The GAE enzymic preparation, when stored at 4°C for a week, 

was quite stable with only 40% loss of activity. The physiological role of GAE in the production of 

geraniol during palmarosa inflorescence development has been discussed (Dubey and Luthra 2001). 

2.4.4 Cy m b o p o g o n j w a r a nC u s a 

The roots of C. jwarancusa (Jones) Schult. also contain essential oil unlike other Cymbopogon species. 

The oil obtained from aerial parts of the plant is rich in monoterpene alcohols, imparting an excellent 

odor. Besides major and trace constituents reported in Table 2.1, several other reports are being mentioned 

here. Cis- and trans-p-menthenols (38%) have been reported as major components of the oil 

(Mathela and Pant 1988). Mathela et al. (1986) reported monoterpene alcohol (25%), piperitols (25%), 

and piperitinone (6.5%), along with α-thujene, camphene, p-cymene, piperitinone, umbellulone, and 

elemol in the essential oil of C. jwarancusa. Piperitone was reported to be the single major constituent 

(Saeed et al. 1978; Thapa et al. 1971), while a mixture of four isomers (3R,4S-(+)cis-p-menth-1-ene- 

3-ol-4 and 3S,4S-(−)-trans and two isomers (cis and trans) with same skeleton having p-menth-2-enl-ol 

constitute 56% of oil. The oil obtained from the roots was rich in monoterpene hydrocarbon and 

sesquiterpene alcohol, the main sesquiterpenoid component being agarospiral (Mathela et al. 1986). 

Two chemical races, C. jwarancusa subsp. jwarancusa and C. jwarancusa subsp. oliveri, have 

been identified from the Kumaon Himalayan region (Mathela et al. 1986); the first one being rich 

in piperitone and the latter having cyclic and monoterpene alcohols but low piperitone. The components 

of the oil of C. jwarancusa differed with growth conditions, particularly geographical locations. 

The composition of the essential oil of Khavi grass, C. jwarancusa, was investigated by glass 

capillary GC in combination with mass spectrometry. Sixty-four compounds were identified, 55 of 

which were reported for the first time. The oil contains a high percentage of piperitone (60%–70%), 

which is mainly responsible for the smell of Khavi grass (Talat et al. 1978). 

The grass found in the Indian Thar desert contained citral, geraniol, geranyl acetate, and piperitone 

as the major components in its essential oil (Shahi 1992; Shahi and Sen 1989, 1993). In an 

unusual finding, paramenthenol was reported to constitute 60% of the oil (Boelens 1994; Mathela 

1991). Piperitone is mainly employed as a starting material for the preparation of several valuable 

perfumery compounds, for example, menthol, thymol, etc. (Guenther 1950), and being the principal 

constituent of the essential oil and possessing a mint or camphor-like odor, this oil is used for scenting 

many technical preparations directly. In a study on growth performance of three cultivars of 

C. jwarancusa (Jorlab-C.j.5, Jorlab-C.j.3, and C.j.), it was found that cultivar Jorlab-C.j.5 proved to


be the best among the three test cultivars in respect of herb yield (21.1 t/ha), oil content (1.6%), and 

major oil constituent, that is, piperitone (83%) (Singh and Pathak 1994). 

2.4.5 Cy m b o p o g o n s C h o e n a n t h u s 

C. schoenanthus (L.) Spreng subsp. proximus Hochst. is primarily native to East Africa and has 

been experimented under cultivation in the surrounding areas (Guenther 1950). The major and 

minor constituents of the oil have been discussed in Table 2.1. Cryptomeridiol, a component in 

the oil, has been found to be responsible for its antispasmodic activity. Diuretic and antihistaminic 

commercial preparations have been made for the oil. Apart from these uses, the oil finds its usual 

employment as a flavoring agent and in the perfumery industry. 

The insecticidal activity of the crude essential oil extracted from C. schoenanthus and its main 

constituent, piperitone, was assessed in different developmental stages of Callosobruchus maculatus 

(Ketoh et al. 2006). Piperitone was more toxic to adults with an LC 50 value of 1.6 μL/L versus 

2.7 μL/L obtained with the crude extract. Piperitone inhibited the development of newly laid eggs 

and neonate larvae, but was less toxic than the crude extract to individuals developing inside the 

seeds (Guillaume et al. 2005). 

2.4.6 ot h e r Cy m b o p o g o n sP e C i e s 

The essential oils of numerous wild-growing Cymbopogon species have been chemically examined, 

and the results reveal that some of them can be used as a source of valuable essential oils. 

2.4.6.1 Cymbopogon caesius 

C. caesius (Nees) Stapf is a loosely tufted perennial grass with erect culms, sometimes stilt-rooted, 

to 2½ m high; of deciduous savanna bushland and wooded grassland; abundant throughout the region 

and, in general, over all of tropical Africa. Rao and Sudborough (1925) investigated this oil for the 

first time and reported limonene, geraniol, perillyl alcohol, and dipentene as the chief constituents 

present in it. About 50 years later, Sinha and Mehra (1977) reported that carvacrol, d-perillaldehyde, 

and d-nerolidol were the main constituents of the oil that were effective against E. coli. However, 

carvone (30%) is the major constituent in the Chinese oil (Liu et al. 1981). Recently, GC-MS analysis 

of the oil from the plants growing in the Northeast region of India have shown 35 compounds, 

out of which 24 have been identified and listed in Table 2.1. The essential oil of C. caesius is well 

placed to be used in perfumery. Detailed analysis by GC-MS is being undertaken, and reports are 

likely to be available shortly. 

2.4.6.2 Cymbopogon coloratus 

A total of 33 compounds were reported by Mallavarapu et al. (1992a) in the chemical profile of the 

essential oil C. coloratus (Nees) Stapf. The main constituents of the oil are myrcene, limonene, 

trans-β-ocimene, linalool, neral, geranial, geraniol (69.11%), geranyl acetate, and elemol. Pilley 

et al. (1928) described the presence of borneol, limonene, and camphene. The oil is also used for 

perfuming soaps and cosmetics (Gupta and Daniel 1982). Bor (1954) was skeptical about the authenticity 

of the species. 

2.4.6.3 Cymbopogon confertiflorus 

The synonym of C. confertiflorus (Steud.) Stapf is reported as C. nardus, which is also known as 

Ceylon citronella as stated earlier. The oil of this particular species is similar to the Ceylonese 

variety but inferior in quality with less geraniol (35%–40%) as the principal constituent (Gupta and 

Daniel 1982).


2.4.6.4 Cymbopogon densiflorus 

C. densiflorus (Steud.) Stapf is a tufted perennial grass with culms 1.8 m high; of open spaces 

along roadsides and wooded grassland; native to central tropical Africa, Gabon to Zimbabwe, and 

introduced into the region (Nigeria and possibly other states) and into Brazil. It is grown in Gabon 

and Nigeria as an ornamental and for its aromatic oil. The leaves are avoided by browsing cattle in 

Zambia. The crushed leaves are used as treatment for rheumatism in Gabon. In Malawi, the flower 

head is smoked in a pipe as a cure for bronchial affections and, for the same complaints, the plant 

sap is used in the Congo (Brazzaville), where it is also given as treatment for asthma and to calm 

fits. It is macerated with Ocimum basilicum (Labiatae), and the compound is used for epilepsy in 

Zaïre. It is conjectured that any medicinal action is due to the camphoraceous volatile oil. The plant 

has also been recorded to be used as a tonic and styptic. It has fetish attributes as well. In Gabon, 

the inflorescence of C. densiflorus is burnt in fumigations required in certain rituals, for example, 

in incantations to chase away malignant spirits, to cleanse those who have lost their spouse, to rejuvenate 

and restore the efficiency of a fetish, as an amulet or talisman when the owner has violated 

a taboo. In Tanganyika, witch doctors smoke the flower panicle, either alone or with tobacco, to 

induce dreams to foretell the future. Huntsmen in Gabon use the plant as a fetish lure for game. The 

oil of the Brazilian plant was compared with the African oil by Koketsu et al. (1976), and olfactory 

analysis showed no noticeable difference. The monoterpenes found in the oil from the flowers and 

leaves of the Zambian plant are shown in Table 2.1. No remarkable difference in the quality of the 

oil from Brazilian and African plants could be recorded (Boelens 1994; Chisowa 1997). 

2.4.6.5 Cymbopogon distans 

The essential oil of C. distans (Nees) Wats. has been studied by GC-MS (Mathela and Joshi 1981; 

Mathela et al. 1989), which showed several monoterpenoids in addition to 19% sesquiterpene alcohols. 

Sobti et al. (1978) reported terpineol (20%) as the major constituent, whereas Thapa et al. 

(1971) and Liu et al. (1981) reported piperitone (30%–40%) and geraniol (10%) as the principal 

constituents of the oil. In another publication (Singh and Sinha 1976), limonene (29%) and methyl 

eugenol (13%) were reported to be the major constituents. Other major constituents have been 

reported in Table 2.1. 

C. distans has been reported to occur in nature in the form of several geographical races. The 

essential oils isolated from the leaves of C. distans chemotype loharkhet and the roots of C. jwarancusa 

(collected from India) were analyzed by GC, GC-MS, and liquid chromatography. Both oils 

were qualitatively very similar in sesquiterpenoid composition but contained different total concentrations 

of sesquiterpenoids (79.6% and 38.0% in the oils of C. distans and C. jwarancusa, respectively). 

The main sesquiterpenoids of the essential oil of C. distans were eudesmanediol (34.4%) and 

5-epi-7-epi-alpha-eudesmol (11.2%). The main sesquiterpenoid in the essential oil of C. jwarancusa 

was agarospirol (9.5%) (Beauchamp et al. 1996; Dunyan et al. 1992). Exhaustive studies have been 

done by Mathela et al. (1988a, 1989) and Mathela and Pant (1988) on the chemical investigations of 

the essential oil, and they characterized C. distans munsiyariensis, which contained eudesmanediol 

(34.4%) along with geraniol (22.89%), neryl acetate (18.34%), neral (14.74%), and limonene (12.08%) 

as the major constituents. Mathela and Pant (1988) reported four chemotypes from the Kumaon 

and Garhwal regions of Uttar Pradesh (India) having marker compounds α-oxobisabolene-1 

(chemotype I); citral, geraniol, and geranyl acetate (chemotype II); piperitone, limonene, and eudesmanediol 

(chemotype III); and sesquiterpene alcohol (chemotype IV) in their oils. One more chemotype 

with chemical marker p-menthol (66.5%) was reported later (Pande et al. 1997). A GC-MS 

study of the hydrocarbon fraction and the fraction containing oxygenated compounds showed the 

presence of 12 monoterpene hydrocarbons (28.4%), 13 sesquiterpene hydrocarbons (32.8%), 3 sesquiterpene 

alcohols (27.2%), 2 esters (7.2%), and 3 carbonyl compounds (4.4%) in the essential oil of 

C. distans. Of these, 27 compounds have been identified (Mathela and Joshi 1981).


2.4.6.6 Cymbopogon khasianus 

The essential oil of C. khasianus (Hack.) Stapf ex Bor has been reported to contain citral (40%–60%) 

and geraniol (70%–80%) as the major constituents (Balyan et al. 1979; Choudhary and Leclercq 1995; 

Rabha et al. 1986; Rabha et al. 1989; Sobti et al. 1978a; Sobti et al. 1982; Thapa et al. 1971; Thapa 

et al. 1976; Verma et al. 1987). Methyl eugenol (75.82%) is the major constituent in C. khasianus. 

2.4.6.7 Cymbopogon ladakhensis 

Very little information is available on C. ladakhensis. However, Gupta and Daniel (1982) have 

reported that piperitone is the chief constituent of this oil. 

2.4.6.8 Cymbopogon microstachys 

The essential oil C. microstachys (Hook.s) Soenarke from the northeastern Indian state of Manipur 

was grown in Bhubaneswar in the state of Orissa in pots. The plants were found to grow well and, 

in 45 days, reached full growth. The essential oil thus obtained from this species was analyzed by 

GC and GC/MS and the results showed that the oil contained (E)-methyl isoeugenol (56.4%–60.7%) 

as the major constituent. This is the first time that an oil of C. microstachys has been found with 

(E)-methyl isoeugenol as the major constituent (Rout et al. 2005). The oil was found to contain about 

60% phenyl propenoids with methyl eugenol (19.5%), methyl isoeugenol (4.2%), elemicin (25.3%), 

and isoelemicin (11.0%). The oil now reported had quite a different composition with (E)-methyl 

isoeugenol as the main constituent (56.4%–60.7%). Other constituents in significant quantities were 

myrcene (7.8%–12.2%), (Z)- and (E)-β-ocimene (2.4%–2.9%), cis-α-bergamotene (0.8%–1.7%), 

trans-α-bergamotene (0.8%–3.4%), germacrene D (0.6%–2.7%), and (Z,E)-α-farnesene (0.4%–2.9%), 

besides an unidentified compound at RT 46.1 min (0.6%–6.0%). In all, 44 components were identified, 

constituting 91.3%–96.2% of the oil. The study shows that the aromatic grass collected in Manipur is 

a chemical variant of C. microstachys. The easy adaptability of the plant to Bhubaneswar conditions, 

high oil yield, and presence of methyl isoeugenol as the major phenyl propenoid may make this a 

commercially important essential oil. Earlier reports have indicated that it contains citral and geraniol 

(Gupta and Daniel 1982). Methyl eugenol, elemicin, and isoelemicin are the major constituents 

(Boelens 1994; Pant et al. 1990) found in a chemical investigation of the oil, along with more than two 

dozen minor constituents: aromadendrene; alloaromadendrene, caryophyllene oxide, 3,4-epoxy-3,7 

dimethyl-1,6-octadione, 6-7-epoxy-3,7-dimethyl-1,3-octadiene, cis-3-hexenol, humulene, limonene, 

cis-limonene oxide, linalool, 6-methyl-5-hepten-2-one methyl isoeugenol, myrcene, nerolidol, 

4-nonanone, trans-ocimene, β-phellendrene, α-pinene, sabinene, terpinen-4-ol, α-terpineol, tricyclene, 

trimethoxy benzaldelyde, and veratraldehyde (Mathela et al. 1990b). 

2.4.6.9 Cymbopogon nervatus 

The essential oil hydrocarbons from C. nervatus (Hochest.) Chiov. have been investigated (Modawi 

et al. 1984), and sesquiterpenes β-selinene, β-elemene, β-bergamotene, and germacrene-D have 

been reported. The antibacterial activity of essential oil of dried inflorescence of C. nervatus 

was investigated. The essential oil remarkably inhibited the growth of tested bacteria except for 

Salmonella typhi. The maximum activity was against Shigella dysenteriae and Klebsiella pneumoniae 

(Kamali et al. 2005). 

2.4.6.10 Cymbopogon olivieri 

The major components of the essential oil of C. olivieri (Boiss.) Bor are iso-pulegol (17.2%), β-pinene 

(24.4%), myrcene (17.9%), piperitone (6.6%), α-pinene (7.3%), and pulegone (10.9%) (Sharma et al. 

1980). The minor components include limonene, linalool, linalyl acetate, phellandrene, piperitenone, 

and terpinene (Bor 1954; Gupta and Daniel 1982). The oil has been tested to be fungitoxic 

(Singh et al. 1980).


2.4.6.11 Cymbopogon parkeri 

The major constituents of the oil of C. parkeri Stapf are nerol (32%), geraniol (33%), farnesol (3.75%), 

geranyl acetate (8.9%), and neryl acetate (3.7%) (Rizk et al. 1985, 1983). The trace constituents 

reported are decane, eudesmol, geraniol, geranyl heptanoate, geranyl hexanoate, geranyl octanoate, 

guaiol, β-gurjunene, limonene, linalool, 14-methyl-heptadecanone, 7-methyl-4-octanone, 12-methyltridecanone, 

neral, neryl butanoate, neryl hexanoate, neryl octanoate, piperitone, α-terpineol, and 

xylene (Gupta and Daniel 1982; Rizk et al. 1983, 1986). A study of the antifungal activity of C. parkeri 

essential oil was done on the growth of Rhizoctonia solani, Pyricularia orizea, and Fusarium 

oxysporum, three important phytopathogenic fungi. 

2.4.7 so M e lesser-kn o w n sP e C i e s 

2.4.7.1 Cymbopogon polyneuros 

The major constituents in this sweet-scented oil obtained from C. polyneuros (Steud.) Stapf. have 

been reported as limonene, perillaldehyde, and perillyl alcohol (Gupta and Daniel 1982; Thapa 

et al. 1971). 

2.4.7.2 Cymbopogon procerus 

Elemicin (34%) and pinene have been described by Gildemeister and Hoffmann (1956) as the major 

constituents of the oil from C. procerus (R. Br.) Domin. 

2.4.7.3 Cymbopogon rectus 

The major constituents of the oil of C. rectus A. Camus are geraniol (40%–60%), methylisoeugenol 

(30.5%), and α-pinene (Gildemeister and Hoffmann 1956). 

2.4.7.4 Cymbopogon sennarensis 

Gildemeister and Hoffmann (1956) have reported that the oil from C. sennarensis (Hochest.) Chiov. 

contains pinene and limonene (13%) and l-methenone-3 (45%). 

2.4.7.5 Cymbopogon stracheyi 

The essential oil of C. stracheyi (Hook. f.) Riaz and Jain bears a very strong aromatic note and contains 

geraniol, citral, geranyl acetate, citronellol, and piperitone (Gupta and Daniel 1982; Mathela 

1991; Thapa et al. 1971). Some analytical studies of plants growing in the Almora region of Uttar 

Pradesh exhibit the presence of piperitone and car-2-ene as major components, along with geraniol, 

α-copaene, β-elemene, caryophyllene, and calarene. Lohani et al. (1986) carried out detailed 

chemical investigation of its oil and revealed the presence of car-2-ene (29.4%) and piperitone 

(47.8%), along with several minor constituents such as acoradiene, β-bisabolene, α-cadinene, camphene, 

trans-caryophyllene, α-copaene, p- cymene, dihydro-α-capaene-8-ol, geraniol, β-elemene, 

α-himachalene, intermediol, juniper camphor, and nerolidol. 

2.4.7.6 Cymbopogon tortilis 

A group from China (Liu et al. 1981) reported that methyl eugenol (55%) is the principal component 

of the oil C. tortilis (Presl.) Hitche. 

2.4.7.7 Cymbopogon travancorensis 

Elimicin is the chief constituent of the oil from C. travancorensis Bor. Other constituents reported 

are borneol, elemol, camphene, limonene, and citral (Gupta and Daniel 1982; Mallavarapu et al. 

1992b; Menon 1956).


2.4.7.8 Cymbopogon goeringii 

The essential oil obtained from C. goeringii (Steud.) A. Camus exhibits antiarrhythmic action on 

isolated guinea pig heart. The results from chemical analysis of the oil are not available (Liu and 

Feng 1989). 

2.4.7.9 Cymbopogon asmastonii 

The compounds reported from the essential oil of C. asmastonii are d-limonene (5.5%), carveol 

(69.5%), and a complex mixture of ketones (17.5%) (Manjoor-i-khuda et al. 1986). 

2.4.7.10 Cymbopogon giganteus 

The composition of the essential oil isolated by hydrodistillation from the leaves of C. giganteus 

Chiov. growing wild in Ivory Coast was determined by GC-RI, GC-MS, and 13 C-NMR after fractionation 

on silica gel. The oil was characterized by high contents of trans- and cis-p-mentha- 

2,8-dien-1-ols (18.4% and 8.7%, respectively), cis- and trans-p-mentha-1(7),8-dien-2-ols (16.0% and 

15.7%, respectively), and limonene (12.5%). A total of 46 components were identified, including 

25 compounds reported for the first time in the oils of this species (Boti et al. 2006). The essential 

oils of fresh flowers (2 samples), leaves, and stems of Cymbopogon giganteus (Hochest.) Chiov. 

from the Cameroon were investigated by GC and GC-MS. More than 55 components have been 

identified in the samples 1 (flowers sample 1), 2 (leaves), 3 (stems), and 4 (flowers sample 2) with 

main compounds possessing the p-menthane skeleton as follows: cis-p-mentha-1(7),8-then-2-ol (1: 

22.8%, 2: 27.7%, 3: 29.1%, 4: 20.5%), trans-p-mentha-1(7),8-dien-2-ol (1: 24.9%, 2: 21.6%, 3: 28.1%, 

4: 26.5%), trans-p-mentha-2,8-then-1-ol (1: 17.3%, 2: 22.1%, 3: 21.4%, 4: 16.3%), and cis-p-mentha- 

2,8-dien-1-ol (1: 8.3%, 2: 5.4%, 3: 4.6%, 4: 9.7%). 

The oils of several other species have also been distilled out, but their chemistry is still not well 

studied. These could well be potentially valuable aromatic crops. Further research is needed to 

reveal the chemistry of these uncommon grasses that can be brought under cultivation on a larger 

scale. The most interesting species are C. caesius, C. coloratus, C. distans, C. khasianus, C. microstachys, 

C. parkeri, and others. On the other hand, all species that have been chemically investigated 

or not need to be cultivated in a particular phytogeographical region and reinvestigated using 

modern spectroscopic methods such as GC-MS, IR, NMR, 13 C-NMR, etc. Popielas et al. (1991) and 

Vole et al. (1997) studied the oil from its inflorescence and identified 18 compounds, most of them 

belonging to oxygenated monoterpenes with p-menthadiene skeleton. It is expected for this species 

that chemotaxonomists will be enabled to classify all the species in a perfect and systematic manner 

so that the prevailing confusion regarding the correct chemotaxonomy of this large genus may be 

removed. Additional components in higher concentrations, responsible for the characteristic aroma 

impressions of the samples from C. giganteus, are especially limonene, trans-verbenol, and carvone 

as well as some other mono- and sesquiterpenes. Antimicrobial activities of the oils from the leaf, 

stem, and flowers were found against Gram-positive and Gram-negative bacteria as well as the yeast 

Candida albicans, and these results were discussed with the compositions of each sample (Leopold 

et al. 2007). 

2.4.8 bi o s y n t h e s i s o f te r P e n e s in Cy m b o p o g o n sP e C i e s 

Terpenoids are a class of compounds derived from the universal precursor isopentenyl diphosphate 

(IPP) and its allylic isomer dimethylallyldiphosphate (DMAPP), also called isoprene units 

(Scheme 2.1). Terpenoid building blocks are then formed through condensation of additional IPP 

moieties (C 5) via prenyltransferases. Monoterpenoids are derived from geranyl pyrophosphate (GPP, 

C 10), sesquiterpenoids are derived from farnesyl pyrophosphate (FPP, C 15), and diterpenoids are


H 

HO 

H 

H 

2 

* 

1 

* CHO 

6 

OH 

H 

OH 

OH 

Glucose-6-phosphate 

Glycolysis 

several steps 

HO 

C-2 in Acetyl-CoA and * in other structures are from C-1, C-6 of Glucose 

(a) Acetoacetyl-CoA thiolase (AACT) 

H 

O 

H 

Dihydroxyacetone 

phosphate 

H 

H 

1 

2 

O 

OH 

3 

* CH2OP Glyceraldehyde-3-phosphate 

NAD O 

+ NADH + H + 

O O 

(a) 

O 

C O 

C 

1 

2 

C 

1 SCoA 

C 

1 SCoA 

C 

Acetyl-CoA 

– 

1 

* 

* 

2 

CoA-SH CO2 2 

3 

CH3 O 

Acetoacetyl-CoA 

Pyruvate 

*6 

* CH2 OH 

(b) 

OH 

* 4 

3 

2 * (c) 

O 

5 1 (d) 

COOH 

SCoA 

3-hydroxy-3-methylglutaryl-CoA 

HO 

(b) HMG CoA Synthase 

(c) HMG-CoA reductase 

(d) NADPH 

6* 

* 4 

5 

3 

OH 

Mevalonate 

6 * 

3 5 

2 

* 

4 

* 

OPP 

Dimethylallyl diphosphate 

1 

* CH2OP 2 * 

(e) ATP 

1 (f) ATP 

COOH 

PPO 

scheme 2.1 MVA-pathway from glucose to IPP and DMAPP. 

(h) 

6* 

* 4 

5 

3 

OH 

2 

* 

1 

COOH 

MVA 5-diphosphate 

6 * 

(g) 

3 5 

2 

4 

* 

OPP 

* 

Isopentenyl diphosphate 

(e) Mevalonate kinase 

(f) Phosphomevalonate kinase 

(g) IPP synthase 

(h) IPP Isomerase


derived from geranylgeranyl pyrophosphate (GGPP, C 20). Even higher-order terpenoids are possible 

through condensation of these intermediates to larger precursor moieties. For example, sterols are 

derived from the triterpenoid squalene (C 30), which contains six isoprene units through condensation 

of two molecules of FPP, and carotenoids (C 40) are largely formed through condensation of two 

molecules of GGPP to yield eight-isoprene-unit compounds. After the formation of the acyclic terpenoid 

structural building blocks (e.g., GPP, FPP, GGPP), terpene synthases act to generate the main 

terpene carbon skeleton. Additional transformations often involving oxidation, reduction, isomerization, 

and conjugation enzymes decorate or alter the main skeleton with varied functional groups 

to yield the tremendously diverse terpenoid family of compounds. The essential oils obtained from 

aroma-bearing plants mainly possess mono- and sesquiterpenoids in high percentage besides a few 

nonterpenoidal compounds. The essential oil obtained from various Cymbopogon species also contains 

a large number of mono- and sesquiterpenoids as discussed in this chapter. 

It has now been unequivocally proven that two distinct and independent biosynthetic routes exist 

to IPP and its allylic isomer DMAPP, the two building blocks for isoprenoids in plants. The cytosolic 

pathway is triggered by acetyl coenzyme A (Scheme 2.1) where the classical intermediate mevalonic 

acid is formed, which in turn converts into IPP and DMAPP. These further combine to elongate into 

sesquiterpenes (C 15) and triterpenes (C 30) (Newman and Chappell 1999). In contrast, the plastidial 

pathway (Eisenreich et al. 1998, 2001; Lichtenthaler 1999; Rohmer 1999) provides precursors for 

the biosynthesis of isoprene (C 5), mono- (C 10), di- (C 20), and tetraterpenes (C 40) (Lichtenthaler 1999; 

Eisenreich et al. 1997, Scheme 2.2). The pathway (Scheme 2.2) is initiated by the transketolase-type 

condensation of pyruvate (C-2 and C-3) and glyceraldehyde-3-phosphate to 1-deoxy-d-xylulose-5phosphate 

(DXP), followed by the isomerization and reduction of this intermediate to 2-C-methyl-derythritol-4-phosphate, 

formation of the cytidine 5′-diphosphate derivative, phosphorylation at C-2, 

and cyclization to 2-C-methyl-d-erythritol-2,4-cyclodiphosphate (MECDP) as the last defined step. 

This is further converted to 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate (HMBDP). HMBDP 

is converted to two C-5 units for further condensation (Scheme 2.3). Later, the genes encoding 

each enzyme of the plastid pathway up to formation of the cyclic diphosphate are isolated from 

plants and from eubacteria where the pathway exists (Takahashi et al. 1998; Bouvier et al. 1998; 

Rohdich et al. 1999, 2000; Sprenger et al. 1997; Lange and Croteau 1999; Little and Croteau 1999; 

Lange et al. 1998; Schwender et al. 1999; Kuzuyama et al. 2000a, 2000b; Lüttgen et al. 2000; Herz 

et al. 2000). 

The cymbopogons have been reported to possess about 100 monoterpenes and around 50 sesquiterpenes 

in all, and thus the MVA and DXP pathways are very likely to be present during the biosynthesis 

of these compounds in the cymbopogons. Not much biosynthetic studies have been carried 

out on these species. However, Akhila (1985) has conducted studies on the biosynthetic relationship 

of citral-trans and citral-cis using doubly labeled [ 14 C, 3 H] precursors. The results revealed that the 

leaf blades of C. flexuosus converted geraniol into citral-trans with the loss of pro-(1S)-hydrogen 

whereas nerol lost the pro-(1R)-hydrogen while being converted into citral-cis. Secondly, the citraltrans 

is converted into citral-cis and vice versa, and there is no separate route for the biosynthesis of 

either of the two aldehydes. The mechanism for interconversion has been shown in Scheme 2.4. 

The biosynthesis of three major components in C. winterianus has been studied by Akhila (1986) 

using 3 H- and 14 C-labeled precursors. Geraniol, citronellol, and citronellal formed in the blades of 

C. winterianus from doubly labeled mevalonic acid predominantly labeled only that C 5 moiety that 

was derived from IPP. This was believed to be due to the presence of a metabolic pool of DMAPP. 

These results later on support the newly discovered theory of a nonmevalonate pathway (DXP pathway) 

in which mevalonic acid is believed to be converted into IPP in cytosol. The very low incorporation 

of radioactivity into monoterpenes (C 10) may be the result of seepage of IPP through the 

plastidial membrane. Monoterpenes are believed to be biosynthesized in plastids. According to the 

reports, geraniol is converted to citronellol, which in turn is transformed into citronellal as per the 

mechanism shown in Scheme 2.5.


H 

H 

1 

2 

O 

OH 

O 

C O 

3 * 

CH2OP C 

– 

+ 

1 

(a) 

1 

OH 

Glyceraldehyde 

moeity 

2 

O 

(b) 

OP 

Glyceraldehyde-3-phosphate 

3 

CH3 Pyruvate moeity O OH 

1-Deoxy-D-xylulose 5-phosphate 

Pyruvate 

1 * 

3 

2 

OH 

4 

OH OH 

(a) DXP Synthase 

(b) �iamine diposphate 

(c) DXP reductoisomerase 

(d) MEP-Cytidylyltransferase 

(e) CDP-Me kinase 

(f) MECDP Synthase 

(g) HMBDP Synthase 

5 

OP 

2-C-Methyl-D-Erythritol 

4-phosphate (MEP) 

1 * 

3 

2 

OH 

4 

OH OH 

5 

OPOPO 

1 

* 

HO 

O 

2 

HO 

4 

O 

3 

NH 2 

N 

Biosynthesis of several mono- and sesquiterpene skeletons and compounds has been worked out 

in various plant species (Akhila et al. 1980a, 1980b, 1980c, 1988a, 1988b, 1987a, 1987b, 1985, 1986, 

1990; Croteau et al. 1981; Crotaeau and Davis 2005). Though about 150 mono- and sesquiterpenes 

are present in all the Cymbopogon species collectively, biosynthetic experiments have not been carried 

out. Based on the literature, two comprehensive schemes (Schemes 2.6 and 2.7) have been made 

showing biosynthetic pathways to most of the mono- and sesquiterpene skeletons and compounds 

5 

N 

(c) 

OP 

H 

H 

OH OH 

4-(Cytidine 5'-diphospho)-2-C-methyl-D-Erythritol (CDP-Me) 

O 

1 * 

3 

2 

O 

P 

OH 4 

OH 

OH OH 

(d) 

O 

5 

P 

O 

H 

O 

-2-C-methyl-D-Erythritol 

2,4-cyclodiphosphate (MECDP) 

H 

1 * 

3 

2 

OP 

4 

O 

OH OH 

scheme 2.2 Nonmevalonate pathway (DXP) to monoterpenes. 

(f) 

(g) 

1 

* 

5 

2 

H 

2 

O 

(e) 

3 

O 

3 

OPOPO 

4 

H 

4 

5 

OH 

H 

OH 

O 

5 

H 

OP 

NH 2 

N 

H 

OH 

2-Phospho-4-(Cytidine 5'-diphospho) 

-2-C-methyl-D-Erythritol (CDP-Me2P) 

3 

1* 

* C is derived from 

Glyceraldehyde-3-phosphate 

is derived from Pyruvate 

2 

4 

5 

OPP 

OH 

1-hydroxy-2-methyl-2-(E)-butenyl 

-4-diphosphate (HMBDP) 

N 

O


3 

3 

3 

OH 

H 

1 

* 

25 

1 

* 

2 

1 

* 

T 

OH 

T 

C 

* 

[1- 14 C, 3 H 1 ]-(1R)-Geraniol Citral-trans 

4 

4 

HMBDP 

DMAPP 

5 

* 

OPP 

OPP 

T 

IPP-isomerase 

scheme 2.3 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate (HMBDP) to IPP and DMAPP. 

OH 

H 

[1- 14 C, 3 H 1 ]-(1S)-Nerol Citral-cis 

derived therefrom. Possible biosynthetic pathways for cadinane, bisabolane, eudesmane, and gurjunane 

compounds have been shown in Schemes 2.8, 2.9, 2.10, and 2.11. 

cis-Farnesyl pyrophosphate (FPP), also known as 2,3-(Z)-farnesyl pyrophosphate (Scheme 2.12), 

has been considered as a universal intermediate starter for many sesquiterpenes. However, it isomerizes 

to its trans-isomer 2,3-(E)-FPP through enzymatic conversion, possibly via nerolidol. FPP also 

cyclizes to a major group of sesquiterpenes such as caryophyllenes and humulenes. For convenience 

and according to generally adopted nomenclature, the numbering of carbon atoms (1 to 15) has been 

O 

Unstable or enzyme 

bond intermediate 

T 

3 

* 

O 

T 

C 

* 

OH 

Free rotation at 

C-3 

3 

T 

Unstable or enzyme 

bond intermediate 

scheme 2.4 Biosynthesis of citral-trans and citral-cis from doubly labeled geraniol and nerol. 

3 

1 

* 

2 

4 

IPP 

5 

OPP 

* 

OH


PPO 

DMAPP 

IPP 

shown in FPP in Scheme 2.12. A nucleophilic attack by an enzyme at C-3 of trans-FPP triggers 

the cyclization process that forms the nine-member cyclic skeleton along with the cyclobutane ring 

with elimination of pyrophosphate from C-1. This is the penultimate precursor of β-caryophyllene 

and β-caryophyllene epoxide. Alternatively, an enzymatic attack at C-10 will facilitate the formation 

of the C11–C1 bond with the elimination of pyrophosphate from C-1 and formation of C 11-ring 

skeleton of α- and β-humulene. 

Alloaromadendrene and aromadendrene are a different group of sesquiterpenes present in 

the essential oils of cymbopogons. A biogenetic route has been proposed from the cis-FPP in 

Scheme 2.13. There are three double bonds in FPP inviting electrophiles (enzymes) to attack them 

at suitable positions depending on the accessibility of the enzyme to the site of the attack. This 

depends upon the stereochemistry and spatial arrangement of the hydrogens and other attached 

atoms such as oxygen and phosphorus. In this case, an enzyme is attracted at C-7 of ∆ 6,7 , which 

attaches to C-2 resulting in the formation of a cyclopentane ring, whereas the other enzyme attacks 

at C-10, enabling ∆ 10,11 to attack at C-1 and release FPP from there. This forms the aromadendrene 

skeleton. The re- and si-face attacks by ∆ 6,7 on C-2 generates the two isomers alloaromadendrene 

and aromadendrene. Another mechanism for the biosynthetic route to butenol and acoradienes has 

been illustrated in Scheme 2.14. These schemes are biogenetic speculations based on chemical considerations 

and mechanisms, and are very good experimental models to be verified by radiotracer 

techniques. 

2.4.9 bioloGiCal aC tiVitie s 

H 

OPP 

The essential oil obtained from various Cymbopogon species is widely used in the perfumery, 

cosmetic, food, and flavor industries. Besides, the oil possess several biological activities (Dikshit 

and Hussain 1984), which have been discussed in detail in Section (2.4.9), but some highlights are 

OPP 

Geranyl Pyrophosphate (GPP) 

Citronellal 

Geraniol 

Citronellol 

scheme 2.5 Biosynthesis of geraniol, citronellol, and citronellal from IPP + DMAPP in Cymbopogon 

winterianus. 

CHO 

OH 

OH


(Z) 

(Z) 

(Z) 

(Z) 

O 

OH 

CHO 

(Z) 

(R) 

OH 

(E) 

(E) 

(R) 

Redoxinterconversion 

CHO 

(E) 

(Z) 

(a) 

(a) 

CH2OR (b) 

p-Cymene γ-Terpinene α-Terpinene Terpinolene o-Cymene 

Carvotanacetone 

(–)-Dihydrocarveol 

R=H, Geraniol 

Citral-trans 

Citral-cis 

R=H, Nerol; R=Ac, Neryl 

acetate;R=PP, Neryl 

pyrophosphate (b) 

7 

(Z) 

(Z) 

? 

(Z) 

2 

1 

(Z) 

O 

(Z) 

(Z) 

(S) O 

(a) 1,8-bond 

(S) OH 

(S) 

HO 

(Z) 

1 

(a) 

(S) 

6 

+ 

3 

(S) 

4 

8 

(S) 

(R) 

4 

+ 

(c) 

OR 

OH 

(a) 

+ 

OH 

(S) 

Camphor 

(S) 

Isoborneol 

4S-(+)-Carvone 

(+)-cis-Carveol 

4R-(+)-Limonene 

Terpinyl carbonium ion/ 

enzyme bond species 

(c) 

Terpinen-4-ol 

α-Terpineol 

(S) O 

8 

Terpinyl carbonium ion/ 

enzyme bond species 

H2C H 

H3C OH 

1 (S) 

1 (S) 

+ 

8 

8 

– 

R=PP Linalyl 

Pyropphosphate 

2 

1 

8 

1,2 Methyl 

Shift 

+ 

2 

Skeleton 

rearrangement 

8 

1 

(Z) 

O 

(Z) 

HO 

(S) 

(Z) 

(Z) 

(Z) 

(a´) 

Camphene 

(R) 

Fenchone 

(S) 

(S) 

Enzyme bonded species 

(R) 

(R) 

(S) 

OR 

(E) 

(a´) 

O 

4R-(-)-Carvone 

(-)-trans-Carveol 

4S-(-)-Limonene 

Δ 4 −Carene 

Δ 3 −Carene 

OH 

7 

+ + 

2 

1 

Hydrogenase 

1,8-Cineole 

3 

Oxidase 

R=H, Geraniol; R=Ac, 

Geranyl acetate; R=PP, 

Geranyl pyrophosphate 

4 

HO 7 

1 

(S) (S) 2 

3 

4 

(R) 

OH 

7 

(S) 

1 

(S) 2 

3 

4 

(S) 

(R) 

CHO 

CH 2 OH 

8 

β-Terpineol 

8 

β-�ujene-4-ol 

8 

�ujyl alcohol 

Citronellal 

Citronellol 

scheme 2.6 Biosynthetic pathways to monoterpene hydrocarbons and oxygenated monoterpenes commonly found in various Cymbopogon species. The most widely 

occurring three possible precursors (C10) GPP, NPP, and LPP have been shown.


OH 

OPP 

Farnesyl Pyrophosphate 

α-Muurolene 

Cadalene 

β-Cadinene 

Cadinane Group 

Bisabolane Group 

α-bisabolene 

β-bisabolene 

Bisabolol 

O 

α-Cadinene γ-Cadinene 

Calamenene 

OH 

OH 

OH 

OH 

OH 

trans-trans-Farnesol 

Eudesmandiol Eudesmane Group 

β-Eudesmol 

α-oxibisabolene 

OH 

Cymbopol 

α-Cubebene 

γ-Cadinol 

CHO 

OH 

Farnesal 

Elemane Group 

Intermediol 

β-Elemene 

HO 

OH 

OH 

Dihydro−α-Copaene-8-ol 

α-Farenesene 

β-Farenesene 

trans-cis-Farnesol 

γ-elemene 

α-elemol 

scheme 2.7 Diversity in biosynthetic pathways to various sesquiterpene skeletons found in various Cymbopogon species from commonly known intermediate cisfarnesylpyrophosphate 

(FPP).


(b) 

X (Enz:) 

(a) X (Enz:) 

H 

X 

Y(Enz:) 

OPP 

(a) 

(b) 

H 

X 

Y(Enz:) 

Y Cadinane skeleton 

Y 

Cadinane 

Compounds 

scheme 2.8 Cyclization of FPP to cadinane skeleton and compounds of cadinane group. X and Y denote 

attacking enzymes involved in biosynthesis. 

PPO 

PPO 

X – 

Enz 

cis-Farnesylpyrophosphate 

scheme 2.9 Cyclization of cis-FPP to monocyclic bisabolane compounds. 

cis-Farnesylpyrophosphate 

Y – 

H+ 

H 

X 

H X 

Y a 

H2C H 

b 

a 

X 

b 

X 

Compounds of 

Eudesmane Group 

scheme 2.10 Possible biogenesis of compounds of eudesmane group in cymbopogons. X and Y denote 

enzymes or their biogenetic equivalents that make a nucleophilic attack on electron-deficient sites of the 

skeleton. 

Y 

H H 

Enz 

X 

H X H H H 

Compounds of Bisabolane 

Group are formed from 

elimination of Hydrogen, 

attack by OH 

Gurjunane 

compounds 

scheme 2.11 Biogenetic pathways to Gurjunane compounds after 1,2 methyl shifts and hydrogen loss 

while forming a cyclopropane ring.


13 

8 

9 

14 

7 

10 

11 

5 

5 

6 

1 (Z) 

2 

OPP 

4 

3 

15 

8 

9 

7 

10 

11 

6 

(E) 

2 

4 

Enz: 

3 

H 

15 C 

H2 12 

13 

12 

1 

OPP 

2,3-(Z)-Farnesyl 

pyrophosphate 

14 

2,3-(E)-Farnesyl 

pyrophosphate 

15 C 

H2 provided here to give the reader an overall view of the pharmacological properties of this oil. The 

important activities include antibacterial, antifungal, anticancer, pesticidal, anthelmintic, mosquito 

repellant, mosquito larvicidal, antiinflammatory, analgesic, and hypoglycemic. The main components 

such as monoterpenes are nonnutritive dietary components found in the essential oils of citrus 

fruits and other plants. A number of these dietary monoterpenes have antitumor activity. For example, 

d-limonene, which comprises >90% of orange peel oil, has chemopreventive activity against 

rodent mammary, skin, liver, lung mammary, lung and forestomach cancers when fed during the 

13 

8 

9 

14 

7 

10 

11 

6 

12 


8 

14 

7 

6 

5 

4 

(S) 

7 

(R) 

O 

7 

9 

Enz: 

13 

10 

11 

12 

(E) 

2 

1 

3 

15C 

H2 OPP 

H 

13 

10 

11 

2 

1 

3 

13 

10 

11 

2 

1 

3 

2,3-(E)-Farnesyl 

pyrophosphate 

12 

β-Caryophyllene epoxide 

12 

β-Caryophyllene 

14 

14 

(Z) 

8 

H 

9 

H 

Enz 

7 

10 

11 

6 

5 

(E) 

2 

1 

4 

3 

15 

14 

(Z) 

13 

8 

7 

9 

10 

11 

12 

12 

6 

5 

4 

3 

(Z) 15 

7 

(Z) 

(R) 

HO 

10 2 

3 

13 12 

(Z) 

8 

9 

7 

6 

5 

α-Humulene 

(α-Caryophyllene) 13 

11 1 

10 

4 

12 

11 

3 

β-Caryophyllene alcohol 

13 

1 2 

(Z) 

15 

12 

β-Humulene 

scheme 2.12 Biosynthesis of caryophyllenes and humulenes. 

5 

2 

1 

4 

3 

Enz 

H


Enz: 

8 

9 

14 

7 

10 

11 

6 

1 

5 

(Z) 

2 

OPP 

13 12 


pyrophosphate 

3 

14 

H2C Enz 

8 

9 

7 

10 

11 

H 

H 

6 

1 

4 

3 

5 

(Z) 

2 

15 

13 12 


1 

7 

11 

H 

12 13 

a-Himachalene 

4 

3 

15 

8 

9 

Enz: 

14 

Enz: 

7 

10 

11 

H 

1 

6 

2 

OPP 

3 H + 

initiation phase. In addition, perillyl alcohol has promotion phase chemopreventive activity against 

rat liver cancer, and germaniol has in vivo antitumor activity against murine leukemia cells. Perillyl 

alcohol and d-limonene also have chemotherapeutic activity against rodent mammary and pancreatic 

tumors. As a result, their cancer chemotherapeutic activities are under evaluation in Phase I 

clinical trials. Several mechanisms of action may account for the antitumor activities of monoterpenes 

(Crowell 1999). 

2.4.9.1 Pain reliever 

Cymbopogon winterianus (Poaceae) is used for its analgesic, anxiolytic, and anticonvulsant properties 

in Brazilian folk medicine. The cited report aimed to perform phytochemical screening and 

investigate the possible anticonvulsant effects of the essential oil from fresh leaves of C. winterianus 

in different models of epilepsy (Quintans-Júnior et al. 2008). Myrcene was identified as the active 

constituent responsible for the activity. The peripheral analgesic effect of myrcene was confirmed 

5 

(Z) 

13 12 


pyrophosphate 

4 

15 

14 

H2C Enz 

H 

H 

5 

8 

7 

6 4 

9 H 1 

3 

10 

Enz 

2 

11 

13 12 


Aromadendrene 

scheme 2.13 Biosynthesis of himachalene and aromadendrene. 

14 

H2C H 

Enz H 

8 

7 

6 

9 H 1 

10 

Enz 

11 

15 

13 12 


H 

7 

5 

2 

Allo-aromadendrene 

4 

3 

15


8 

9 

13 

14 

7 

10 

11 

1 

6 

12 

Enz: 

5 

(Z) 

2 

OPP 


pyrophosphate 

8 

9 

14 

7 

10 

11 

1 

6 

5 

2 

OPP 

4 

3 

H 

H 

15 

8 

9 

13 

13 12 

Enzyme bonded species or 

electronically motivated reaction 

14 

Enz: 

8 

9 

13 

7 

10 

11 

1 

6 

(Z) 

2 

OPP 

12 

5 

(Z) 


pyrophosphate 

4 

3 

H 

4 

3 

H 

15 

15 

14 

7 

10 

11 

12 

Enz: 

12 

1 

6 

9 

8 

10 

11 

Acoradiene 

by testing a saturated compound preparation on the hyperalgesia induced by prostaglandin in the 

rat paw test, and upon the contortions induced by intraperitoneal (ip) infections of iloprost in mice 

(Lorenzetti et al. 1991). Oral administration of an infusion of C. citratus fresh leaves to rats produced 

a dose-dependent analgesia for the hyperalgesia induced by subplanter infections of either caragenin 

or prostaglandin E2, but did not affect that induced by dibutyryl cyclic AMP. These results indicated 

a peripheral site of action. In contrast to the central analgesic effect of morphine, myrcene 

did not cause tolerance on repeated infection in rats. This analgesic property supports the use of 

lemongrass tea as a sedative in folk medicine. It is suggested that terpenes such as myrcene may 

constitute a lead for the development of new peripheral analgesics with a profile of action different 

from that of aspirin-like drugs. 

5 

(Z) 


Enz 

12 

C 

H2 scheme 2.14 Biosynthetic routes to butenol and acoradiene. 

13 

8 

9 

14 

7 

10 

11 

H 

2 

14 

7 

2 

1 

13 

4 

3 

H 

OH 

6 

3 

15 

15 

H 

5 

4 

10 

α-butenol β-butenol 

6 

1 

5 

(Z) 

2 

H 

4 

3 

15 

8 

9 

9 

13 

14 

8 

7 

10 

14 

2 

1 

11 

6 

6 

5 

15 

2 

12 

5 

4 

4 

3 

H 

15 

�is intermediate is not possible 

stereochemically hence another 

mechanism is proposed 

12 

10 

11 

7 

1 

13 

1 

6 

3 

OH 

15


2.4.9.2 activity against leukemia and malignancy 

The essential oil from a lemongrass variety of Cymbopogon flexuosus (CFO) and its major chemical 

constituent sesquiterpene isointermedeol (ISO) were investigated for their ability to induce apoptosis 

in human leukemia HL-60 cells because dysregulation of apoptosis is the hallmark of cancer 

cells. CFO and ISO inhibited cell proliferation with 48 h IC 50 of ~30 and 20 μg/mL, respectively 

(Kumar et al. 2008). Two active compounds, d-limonene and geraniol, were isolated by glutathione- 

S-transferase (GST) assay and fractionation of lemongrass (C. citratus) oil. These were tested for 

their capacity to induce activity of the detoxifying enzyme GST in several tissues of the female A/J 

mice. d-Limonene increased GST activity two- to threefold than controls in the mouse liver and 

the mucosa of the small and large intestines. Geraniol showed high GST- inducing activity in the 

mucosa of the small and large intestines, which was about 2.5-fold greater than controls. Induction 

of increased GST activity, which is believed to be a major mechanism for chemical carcinogen 

detoxification, has been recognized as one of the characteristics of the action of anticarcinogens 

(Zheng et al. 1993). 

The essential oil from C. citratus and its isolated principal citral have been tested for cytotoxicity 

against P388 leukemia cells. The cytotoxicity of citral, IC 50 against P388 mouse leukemia cells was 

71 µg/mL (Dubey et al. 1997). In another experiment, IC 50 of C. citratus oil in P388 leukemia cells 

was found to be 5.7 µg/mL (Dubey et al. 1997). 

2.4.9.3 activation of male hormones 

The antimale sex hormone agent is a 5-reductase inhibitor that converts testosterone to active dihydrotestosterone. 

This agent is extracted from the leaves, stems, rhizomes, roots, or whole plant of 

C. flexuosus. The composition containing the antimale sex hormone agent is especially useful as 

hair growth stimulants (Kisaki et al. 1998). 

2.4.9.4 activity against Worms 

The essential oil from C. martinii var. motia, in varying concentrations (0–0.4%), have shown to 

have good to excellent anthelmintic activity against tapeworms, round worms, and earthworms in 

in vitro tests (Sangwan et al. 1985). The activity exceeded that of the drug piperazine phosphate 

(Siddiqui and Garg 1990). Helminthiasis is one of the most important groups of parasitic diseases 

in the Indo–Pakistan subcontinent, resulting in heavy production losses in livestock. A wide variety 

of anthelmintics is used for the treatment of helminths in animals. However, the development of 

resistance in hel minths against commonly used anthelmintics has always been a challenge faced by 

the animal health care professionals. Therefore, exploitation of the anthelmintic potential of plants 

indigenous to the Indo–Pakistan subcontinent is an area of research interest (Akhtar et al. 2000). 

2.4.9.5 lowering blood sugar 

A study was designed to investigate the hypoglycemic and hypolipidemic effects of the single daily 

oral dosing of 125–500 mg/kg of fresh leaf aqueous extract of Cymbopogon citratus Stapf (CCi) in 

normal male Wistar rats for 42 days (Adeneye and Agbaje 2007). In another report, Cymbopogon 

proximus herb was assessed by Eskandar and Won Jun (1995) for hypoglycemic and hyperinsulinemic 

action on alloxan diabetic rats. A dose of 1.5 mL of herb suspension/100 g B weight was orally 

administered to the rats for intervals of 4, 8, and 16 days. The results revealed that considerable 

hypoglycemic effect was exerted after 16 days. The level of serum insulin was also increased in 

diabetic rats. 

2.4.9.6 Potential to repel mosquitoes and Kill the larvae 

Ointment and cream formulations of lemongrass oil in different classes of base and the oil in liquid 

paraffin solution have been evaluated for mosquito repellency in a topical application. Mosquito


repellency was tested by determining the bite deterrence of product samples applied on an experimental 

bird’s skin against a 2-day-starved culture of Aedes aegypti L. mosquitoes. The 1% v/v 

solution and 15% v/w cream and ointment preparations of the oil exhibited ≥50% repellency lasting 

2–3 h, which may be attributed to citral, a major oil constituent. This activity was comparable to that 

of a commercial mosquito repellent. Base properties of the lemongrass oil formulations influenced 

their effectiveness. The oil demonstrated efficacy from the different bases in the order of hydrophilic 

base > emulsion base > oleaginous base (Oyedele et al. 2002). Ansari and Razdan (1995) studied 

various essential oils for their mosquito-repellent activity. Essential oils from C. martinii var. sofia, 

C. citratus, and C. nardus were found as effective as chemical base oil. The percent protection 

against Culex quinquefasciatus ranged third 95%–96%. Fractional distillation of Ceylon citronella 

(C. nardus) oil yielded 13 fractions. Monoterpene hydrocarbon fractions were highly lethal to late 

third instar Culex quinquefasciatus larvae. The results suggested that myrcene was responsible for 

this activity. Elemol and/or methyl iso-eugenol were identified as active larvicidal principles in the 

latter fractions. The residue after the fractional distillation also possessed considerable larvicidal 

activity (Ranaweera and Dayananda 1997). 

2.4.9.7 activity to reduce edema 

The species of Cymbopogon giganteus is widely used in traditional medicine against several diseases. 

This study reports the inhibitory effect produced by the chemical constituents of the essential 

oil from leaves of C. giganteus of Benin in vitro on 5-lipoxygenase, and has been found useful 

as an antiinflammatory agent. The scientists assayed the antiradical scavenging activity of the 

sample by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method (Alitonou et al. 2006). Earlier, the 

antiinflammatory activity of the oil was attributed to the inhibition of the prostaglandin pathway 

(Krishnamoorthy et al. 1998). Oral administration of essential oils extracted from C. martinii 

leaves produced dose-dependent inhibition of carrageenan-induced paw edema in experimental 

male albino rats. 

2.4.9.8 Potential to control aging Process 

Leaves from cultivated Cymbopogon citratus were extracted with methanol, 80% aqueous ethanol, 

and water (infusion and decoction), and the extracts were assessed for their antiradical capacity 

by 2,2-diphenyl-1-picrylhydrazyl (DPPHʹ) assay; the infusion extract exhibited the strongest 

activity. Tannins, phenolic acids (caffeic and p-coumaric acid derivatives), and flavone glycosides 

(apigenin and luteolin derivatives) were identified in three different fractions obtained from an 

essential-oil-free infusion, and a correlation with their scavenger capacity for reactive oxygen species 

was studied. The tannin and flavonoid fractions were the most active against species involved 

in oxidative damage processes. In the flavonoid fraction, representing 6.1% of the extract, 13 compounds 

(O- and C-glycosylflavones) were tentatively identified by high-performance liquid chromatography, 

coupled to photodiode-array and electrospray ionization mass spectrometry detectors 

(HPLC–PDA–ESI/MS), nine of which were identified for the first time in this plant, all of them 

being C-glycosylflavones (mono-C-, di-C- and O,C-diglycosylflavones). The potential beneficial 

and protective value of the identified polyphenols for human health is discussed (Figueirinha et al. 

2008). Hyalurodinase inhibitors are extracted from C. nardus and some other plants for the preparation 

of cosmetics. Hyalurodinase inhibitors prevented the degradation of aging-related hyaluronic 

acid (Namba et al. 1995). Antioxidant activity of C. schoenanthus was measured by DPPH assay. 

The results ranged from 36.0% to 73.8% (2 μL of essential oil per milliliter of test solution). The 

antioxidant activity was also assayed using the β-carotene–linoleic acid bleaching method. The best 

results (IC 50 = 0.47 ± 0.04 mg mL −1 ) were obtained with the fresh leaves of plants collected in the 

desert region. The greatest acetylcholinesterase inhibitory activity (IC 50 = 0.26 ± 0.03 mg mL −1 ) was 

exhibited by the essential oil of the fresh leaves from the mountain region (Khadri et al. 2008).


2.4.9.9 activity against Pests 

The susceptibility of Spodoptera litura larvae to different concentrations (0.2%–0.8%) of the essential 

oil of C. citratus has been studied in relation to host plant resistance in peanut. Field trials indicated 

that larvae developing on the most susceptible variety had the lowest mortality due to biopesticide 

lemongrass oil. The larvae treated with the oil before feeding showed significant higher mortality on 

the diet containing resistant pods than on that containing susceptible pods (Rajapakse and Jayasena 

1991). The essential oils from C. martinii var. motia, C. flexuosus, and C. winterianus are reported 

to possess insect-repellant, nematicidal, and insect-attractant properties (Ahmad et al. 1993). 

A number of essential oils including citronella (C. winterianus) and palmarosa (C. martinii) 

showed pesticidal activity against the stored grain insect Tribolium castaneum (Naik et al. 1995). 

Within a storage period of 10 days, samples of maize and cowpea treated with lemongrass powder 

and essential oil showed no physical deterioration (Adegoke and Odesola 1996). 

2.4.9.10 activity against microbes 

The essential oil of C. martinii var. motia and its different dilutions have shown significant antibacterial 

activity against Staphylococcus aureus, S. pyagens, E. coli, and Corynebacterium ovis 

(Gangrade et al. 1990). 

The essential oils of lemongrass (C. citratus), palmarosa (C. martinii var. motia), and khavi 

grass (C. jwarancusa) were tested for antibacterial property against E. coli, S. aureus, Shigella flexneri, 

and Salmonella typhi. Lemongrass oil was the most active and caused complete inhibition of 

S. aureus at less than 400 ppm. Palmarosa was more active against S. flexneri and S. typhi, whereas 

khavi grass showed less activity than lemongrass and palmarosa. The activity of the oil might be 

attributed to the components citral, geraniol, and piperitone (Syeed et al. 1990). 

The essential oil from the leaves of C. martinii was tested for toxicity against Fusarium oxysporum. 

Toxicity was the strongest as the mycelial growth of the pathogen was inhibited. Fungitoxicity 

remained unchanged in temperature treatment after a long storage period. It had no effect on the 

Cajanus cajan plant (Shrivastava et al. 1990). The essential oil of C. nardus exhibited a very good 

order of antifungal activity (Lemos et al. 1994). 

The effect of auto-oxidation of lemongrass (C. citratus) oil on its antibacterial activity was studied. 

Using the active oxygen method, the oil was found to undergo rapid oxidation under accelerated 

test conditions. The oxidized oil samples were found to have reduced activity against bacteria. The 

activity was completely lost in extensively oxidized oil samples. Inclusion of antioxidants in the oil 

samples reduced the rate of oxidation and enhanced the antibacterial activity of the oil. The effects 

of the antioxidants were concentration-dependent, and at their effective concentration oxidation was 

completely prevented for the period of the test (Orafidiya 1993). 

The inhibitory effect of lemongrass (C. flexuosus) essential oil isolated from local and Thai 

cultivars against pathogenic fungi were reviewed. No significant difference was found. The oil completely 

inhibited the growth of Monilia sitophilia, Penicillium digilotum, Aspergillus parasiticus, 

A. niger, and A. fungis (Shadab-Qamar et al. 1992). 

The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the 

oil obtained from lemongrass (C. citratus), and citral against 35 clinical isolates of four dermatophytes 

were determined by the agar dilution method. The MIC and MLC of lemongrass oil were 

found to be higher than those of citral. The mode of action of lemongrass oil and citral were proven 

to be fungicidal. A comparative study of efficacy of cream containing four different concentrations 

of lemongrass oil was performed in vitro by hole diffusion assay. The 2.5% lemongrass oil was 

demonstrated to be the minimum concentration for the preparation of an antifungal cream for subsequent 

clinical study (Wannissorn et al. 1996). 

The essential oil from several plants, including lemongrass (C. citratus), were tested for antimicrobial 

activities against Paenibacillus larvae, the causal agent of American Foul Broad (AFB)


disease of honeybees. Trials for determining the MIC of the oil revealed that lemongrass and 

thyme were most effective. The results indicated that lemongrass and thyme oils could be used as 

effective inhibitors of AFB in honeybee colonies (Allpi et al. 1996). 

Thirteen essential oils of African origin (mostly from the Cameroon) were correlated with the 

antimicrobial activities of the oil toward six microbial strains: S. aureus, B. coli, Proteus mirabilis, 

Klebsiella pneumoniae, Candida albicans, and Pseudomonas aeruginosa. The oil of C. citratus 

displayed noteworthy antifungal and antibacterial properties (Chalchat et al. 1997). Fresh oil as 

well as 2-, 7-, and 12-year-old oils of a local variety of lemongrass (C. citratus) were distilled and 

redistilled, and tested against B. coli, S. aureus, Shigella flexneri, Salmonella typhi, Para-A, and 

Klebsiella pneumonae. The oil that was kept for two years exhibited, after redistillation, maximum 

activity due to its high citral content. S. flexneri and S. typhi were inhibited effectively at low doses 

of the oil. The inhibition appeared to be mostly by the citral content of the oil (Syeed et al. 1990). 

During the screening of some aromatic plants for fungitoxicity of their volatile oils, C. pendulus 

var. Praman exhibited the strongest activity, completely inhibiting the mycelial growth of the test 

organisms Microsporuin gypseum and Trichophyton mentagrophytes. The volatile oil distilled from 

fresh leaves was found to be fungicidal at its MIC of 200 µg/mL, inhibiting heavy inocula of the 

test fungi. During the testing of its fungitoxic spectrum, it also inhibited mycelial growth of three 

other fungi and was found to be more active than some commercial drugs tested (Pandey et al. 

1996). Essential oils obtained from the leaves of 29 medicinal plants commonly used in Brazil were 

screened against 13 different E. coli serotypes. The oils were obtained by water distillation using a 

Clevenger-type system, and their MIC was determined by the microdilution method. Essential oil 

from C. martinii exhibited a broad inhibition spectrum, presenting strong activity (MIC between 

100 and 500 μg/mL) against 10 out of 13 E. coli serotypes: three enterotoxigenic, two enteropathogenic, 

three enteroinvasive, and two shiga-toxin producers. C. winterianus strongly inhibited two 

enterotoxigenic, one enteropathogenic, one enteroinvasive, and one shiga-toxin producer serotypes. 

Aloysia triphylla also shows good potential to kill E. coli with moderate-to-strong inhibition. Other 

essential oils showed antimicrobial properties, although with a more restricted action against the 

serotypes studied. Chemical analysis of C. martinii essential oil performed by GC and GC–MS 

showed the presence of compounds with known antimicrobial activity, including geraniol, geranyl 

acetate, and trans-cariophyllene, which, tested separately, indicated geraniol as antimicrobial active 

compound. The significant antibacterial activity of C. martinii oil suggests that it could serve as a 

source for compounds with therapeutic potential (Duarte et al. 2006). 

An essential oil from a lemongrass variety of C. flexuosus (CFO) and its major chemical constituent 

sesquiterpene isointermedeol (ISO) were investigated for their ability to induce apoptosis 

in human leukemia HL-60 cells because dysregulation of apoptosis is the hallmark of cancer cells. 

CFO and ISO inhibited cell proliferation with 48 h IC of ~30 and 20 μg/mL, respectively. Both 

induced concentration-dependent strong and early apoptosis as measured by various endpoints, 

for example, annexin V binding, DNA laddering, apoptotic bodies formation, and an increase in 

hypodiploid sub-G0 DNA content during the early 6 h period of study. This could be because 

of early surge in reactive oxygen species (ROS) formation with concurrent loss of mitochondrial 

membrane potential observed. Both CFO and ISO activated apical death receptors TNFR1, DR4, 

and caspase-8 activity. Simultaneously, both increased the expression of mitochondrial cytochrome 

c protein with its concomitant release to cytosol leading to caspase-9 activation, suggesting thereby 

the involvement of both the intrinsic and extrinsic pathways of apoptosis. Further, Bax translocation 

and decrease in nuclear NF-κB expression predict multi target effects of the essential oil and 

ISO while both appeared to follow similar signaling apoptosis pathways. The easy and abundant 

availability of the oil combined with its suggested mechanism of cytotoxicity makes CFO highly 

useful in the development of anticancer therapeutics (Kumar et al. 2008). The essential oil from a 

lemon grass variety of Cymbopogon flexuosus was studied for its in vitro cytotoxicity against twelve 

human cancer cell lines. The in vivo anticancer activity of the oil was also studied using both solid 

and ascitic Ehrlich and Sarcoma-180 tumor models in mice. In addition, the morphological changes


in tumor cells were studied to ascertain the mechanism of cell death. The in vitro cytotoxicity studies 

showed dose-dependent effects against various human cancer cell lines (Sharma et al. 2009). 

C. winterianus (Poaceae) is used for its analgesic, anxiolytic, and anticonvulsant properties in 

Brazilian folk medicine and these reports are aimed to perform phytochemical screening and to 

investigate the possible anticonvulsant effects of the essential oil from fresh leaves of C. winterianus 

in different models of epilepsy. The phytochemical analysis of the oil showed the presence of 

geraniol (40.06%), citronellal (27.44%), and citronellol (10.45%) as the main compounds. A behavioral 

screening demonstrated that the essential oil (100, 200, and 400 mg/kg, ip) caused depressant 

activity on CNS. When administered concurrently (200 and 400 mg/kg, ip) it significantly reduced 

the number of animals that exhibited PTZ- and PIC-induced seizures in 50% of the experimental 

animals (p < 0.05). Additionally, EO (100, 200, and 400 mg/kg, ip) significantly increased (p < 

0.05) the latencies of clonic seizures induced by STR. Our results demonstrated a possible anticonvulsant 

activity of the essential oil (Quintans-Júnior et al. 2008). 

reFerences 

Abdullah MA, Foda YH, Saleh M, Zaki MSA, Mostafa MM. 1975. Identification of the volatile constituents 

of the Egyptian lemongrass oil I. Gas chromatographic analysis. Nahrung 19: 195–200 (C.A., 83, 

48089 u). 

Abegaz B, Yohannes PG, Deiter RK. 1983. Constituents of essential oil of Ethiopian Cymbopogon citratus 

Stapf. J Nat Prod 46: 424–426. 

Adegoke GO, Odesola BA. 1996. Storage of maize and cowpea and inhibition of microbial agents of biodeterioration 

using the powder and essential oil of lemongrass (C. citratus). Int Biodeterioration 

Biodegrad 37: 81–84. 

Adeleke AK, Adebola OO, Adeolu OA. 2001. Volatile leaf oil constituents of Cymbopogon citratus (DC) Stapf. 

Flav Frag J 16(5): 377, 378. 

Adeneye AA, Agbaje EO. 2007. Hypoglycemic and hypolipidemic effects of fresh leaf aqueous extract of 

Cymbopogon citratus Stapf. in rats. J Ethnopharmacol 112(3): 440–444. 

Ahmad R, Sheikh V, Ahmad A, Ahmad M. 1993. Essential oils as insect and animal attractant and repellants. 

Hamdard Med 36: 99–105. 

Ahmed ZF, Rizk AM, Hammouda FM. 1970. Postep Dziedzinie Leku Rosi. Proc Ref Dosw Wygloszone Symp 

20–23 (C.A.78: 94856-u). 

Akhila A, Francis MJO, Banthorpe DV. 1980a. Biosynthesis of carvone in Mentha spicata. Phytochemistry 19: 

1433–1437. 

Akhila A, Rani K, Thakur RS. 1990. Biosynthesis of artemisinic acid in Artemisia annua. Phytochemistry 

29(7): 2129–2132. 

Akhila A, Sharma PK, Thakur RS. 1988a. 1,2-Hydrogen shifts in the formation of Sesquithujane skeleton in 

ginger rhizomes. Phytochemistry 27(11): 3471–3473. 

Akhila A, Sharma PK, Thakur RS. 1987a. 1,2-Hydrogen shifts during the biosynthesis of Patchoulenes in 

Pogostemon cablin. Phytochemistry 26(10): 2705–2707. 

Akhila A, Sharma PK, Thakur RS. 1988b. Biosynthetic relationship in Patchouli alcohol, Seychellene and 

Cycloseychellene in Pogostemon cablin. Phytochemistry 27(7): 2105–2108. 

Akhila A. 1980b. Banthorpe DV: Biosynthetic origin of gem-methyls of geraniol. Phytochemistry 19: 

1429–1430. 

Akhila A. 1980c. Biosynthesis of the skeleton of Pulegone in Mentha pulegium. Pflanzenphysiol Zeitschrift fur 

99(3): 277–282. 

Akhila A. 1985. Biosynthetic relationship of citral-trans and citral-cis in Cymbopogon flexuosus (Lemongrass). 

Phytochemistry 24(11): 2585–2587. 

Akhila A. 1986. Biosynthesis of monoterpenes in Cymbopogon winterianus. Phytochemistry 25(2): 421–424. 

Akhila A. 1987b. Biosynthesis of menthol and related monoterpenes in Mentha arvensis. J Plant Physiol 

126(4/5): 379–386. 

Akhtar MS, Iqbal Z, Khan MN, Lateef M. 2000. Anthelmintic activity of medicinal plants with particular reference 

to their use in animals in the Indo–Pakistan subcontinent. Small Ruminant Res 38(2): 99–107. 

Alam K, Agua T, Manen H, Taie R, Rao KS, Burrows I, Huber ME, Rali T. 1994. Preliminary screening of sea 

weeds, sea grass for antimicrobial and antifungal activity. J Pharmacognosy 32: 169–399.


Alitonou GA, Avlessi F, Sohounhloue DK, Agnaniet H, Bessiere JM, Menut C. 2006. Investigations on the 

essential oil of Cymbopogon giganteus from Benin for its potential use as an anti-inflammatory agent. Int 

J Aromatherapy 16(1): 37–41. 

Allpi AM, Ringuilet JA, Ceremele El, Re MS, Henning CP. 1996. Antimicrobial activity of some essential oil 

against Paenibacillus larvae, the causal agent of American foulbrood disease. J Herbs Spice Med Plants 

4: 9–16. 

Anonymous. 1950. The Wealth of India, Vol. II, pp. 411–419, CSIR, New Delhi. 

Anonymous. 1952. Indian Standard Specifications, Indian Standards Institutions, New Delhi. 

Anonymous. 1958. Essential Oils and Aromatic Chemicals, Symposium at Dehradun, CSIR, New Delhi. 

Anonymous. 1973. Application of gas liquid chromatography to the analysis of essential oil III. Determination 

of geraniol in oils of citronella. Analyst 98: 823–829. 

Anonymous. 1978. Insect repellent complex. Pat Ger Offen 2, 752, 140, 24 May 1978 (C.A. 89: 175043 f). 

Anonymous. 1980. Terpenoids from palmarosa grass (Cymbopogon martinii var. motia) R.A K. Riechst. Aromen 

Kosmet 30: 20–22 (C.A. 92: 160599e). 

Ansari MA, Razdan RK. 1995. Relative efficacy of various oils in repelling mosquitoes. Indian J Mal 32: 

104–111. 

Ansari SH, Ali M, Siddiqui AA. 1996. Evaluation of chemical constituents and trade potential of Cymbopogon 

citratus (Lemongrass). Hamdard Med 39: 55–59. 

Ansari SH, Quadry JS. 1987. TLC and GLC studies on Khawi grass oil. Indian J Nat Prod 3: 10–12. 

Arctander S. 1960. Perfume and Flavour Materials of Natural Origin. Allured Publishing, Elizabeth, New Jersey. 

Arora R, Pandey GN. 1977. The application of essential oils and their isolates for blue mold decay control in 

Citrus reticulata Blanco. J Food Sci Technol 14: 14–16. 

Atal CK, Bradu BL. 1976a. Search for aroma chemicals of industrial value from genus Cymbopogon. Part II. 

C. pendulus (Nees ex Steud.) Wats. (Jammu lemongrass)—a new superior source of citral. Indian J 

Pharmacol 38: 61–63. 

Atal CK, Bradu BL. 1976b. Search for aroma chemicals of industrial value from genus Cymbopogon Pt. III: 

Cymbopogon pendulus (Nees ex Steud.) Wats. (Jammu lemongrass), a new superior source of citral. 

Indian Perfumer 20: 29–33. 

Atal CK, Bradu BL. 1976c. Search for aroma chemicals of industrial value from genus Cymbopogon Pt. IV. 

Chandi and Kolar grasses as source of methyl eugenol. Indian Perfumer 20: 35–38. 

Atal CK, Bradu BL. 1976d. Search for aroma chemicals of industrial value from Cymbopogon Part V. Chandi 

and Kolar grasses as source of methyl eugenol. Indian J Pharm 38: 63, 64. 

Baiswara RB, Nair KNG, Mathew TV. 1976a. Detection of adulteration of palmarosa oil in ginger grass oil by 

thin layer chromatography. Res Ind 21: 37–39. 

Baiswara RB, Nair KNG, Mathew TV. 1976b. Detection of ginger grass oils in lemongrass oil by thin layer 

chromatography. Res Ind 21: 39, 40. 

Balyan SS, Shahi AK, Choudhury SN, Singh A, Atal CK. 1979. Performance of five strains of genus 

Cymbopogon at Jammu. Indian Perfumer 23: 121–124. 

Baruah P, Mishra BP, Pathak MG, Ghosh AC. 1995. Dynamics of essential oil of Cymbopogon citrates (D.C.) 

Stapf. under rust disease indices. J Essen Oil Res 7: 337–338. 

Baslas RK, Baslas KK. 1968. Essential oil potentialities of Kumaon. Indian Perfumer 12: 3–6. 

Baslas RK. 1970. Chemistry of Indian essential oils. Part IX. Flav Industry 1: 475–478. 

Beauchamp PS, Dev V, Docter DR, Ehsani R, Vita G, Melkani AB, Mathela CS, Bottini AT. 1996. Comparative 

investigation of the sesquiterpenoids present in the leaf oil of Cymbopogon distans (Steud.) 

Wats. var. loharkhet and the root oil of Cymbopogon jwarancusa (Jones) Schult. J Essen Oil Res 8: 

117–121. 

Beech DF. 1977. Growth and oil production of lemongrass (C. citratus) in the Ord Irrigation Area, Western 

Australia. Aust J Exp Agric Anim Husb 17: 301–307. 

Bhattacharya AK, Kaul PN, Rao BRR, Mallavarapu GR, Ramesh S. 1997. Interspecific and inter cultivar variations 

in the essential oil profiles of lemongrass. J Essen Oil Res 9: 361–364. 

Bhattacharya SC. 1970. Perfumery chemicals from indigenous raw materials. J Indian Chem Soc 47: 

307–313. 

Bhaumik SK, Rao VS. 1978a. Studies on prehydrolysis sulfate pulp from Cymbopogon grass (oil extracted). 

Indian Pulp Pap 33: 3–5. 

Bhaumik SK, Rao VS. 1978b. Evaluation of citronella grass (waste) as a raw material for paper making. Indian 

Pulp Pap 33: 17–19. 

Blake O, Booth R, Carrigon D. 1993. The tanin content of herbal teas. Br J Phytotherapy 3: 124–127.


Blanco MM, Costa C, Freire AO, Santos Jr. JG, Costa M. 2007. Neurobehavioral effect of essential oil of 

Cymbopogon citratus in mice. Phytomedicine 16: 265–270. 

Boelens MH. 1994. Sensory and chemical evaluation of tropical grass oils. Perfum Flavor 19: 29–45. 

Bor NL. 1954. The genus Cymbopogon Spreng. In India, Burma and Ceylon Part II. J Bombay Nat Hist Soc 

52: 149–183. 

Borovik VN, Kuravskaya IM. 1977. Flammability and explosiveness of some synthetic perfumes and intermediate 

products. Maslo-Zhir Prom-st 10: 34, 35 (C.A.89: 48794-b). 

Boti JB, Muselli A, Tomi F, Koukoua G, N’Guessan TY, Costa J, Casanova J. 2006. Combined analysis of 

Cymbopogon giganteus Chiov. leaf oil from Ivory Coast by GC/RI, GC/MS and 13 C-NMR C.R. Chimie 

9: 164–168. 

Bottini AT, Dev V, Garfagnoli DJ, David J, Hope H, Joshi P, Lohani H, Mathela CS, Nelson TB. 1987. 

Isolation and crystal structure of a novel dihemiacetal bis monoterpenoid from Cymbopogon martinii. 

Phytochemistry 26: 2301, 2302. 

Bouvier F, d’Harlingue A, Suire C, Backhaus RA, Camara B. 1998. Dedicated roles of plastid transketolases 

during the early onset of isoprenoid biogenesis in pepper fruits. Plant Physiol 117: 1423–1431. 

Brazil S, Gilberto A de A, Bauer L. 1971. Essential oil of Cymbopogon citratus. Rio Grande do Sul 52: 

193–196 (C.A., 76, l3l371-p). 

Bruns K, Heinrich B, Pagel I. 1981. Citronellol. Untersuchung von Handels und Hybridolen Verschiedener 

Provenienz in Vorkommen und Analytic Atherischer Ole, Band 2 (Kubeczkaeds KH, Ed.), G. Thieme 

Verlag, Stuttgart, Germany. 

Carlini EA, Contar JDP, Silva-Filho AR, Da Silveira-Filho NG, Frochtengarten ML, Bueno OFA. 1986. 

Pharmacology of lemongrass (Cymbopogon citratus Stapf.). I. Effects of teas prepared from the leaves 

on laboratory animals. J Ethnopharmacol 17(1): 37–64. 

Chakrabarti MM, Ghosh SK. 1974. Essential oils from plant grown in West Bengal. Indian Perfumer 18: 

35–39. 

Chalchat JC, Garry RP, Menut C, Lonaly G, Malhuret R, Chopineau J. 1997. Correlation between chemical 

composition and antimicrobial activity. VI. Activity of some African essential oils. J Essen Oil Res 9: 

67–75. 

Chauhan YS, Singh KK, Ganguly D. 1976. Improvement of Java citronella (C. winterianus Jowitt) by chemical 

mutagenesis. Indian Perfumer 20: 73–77. 

Cherian S, Chattattu GJ, Viswanathan TV. 1993. Chemical composition of lemongrass varieties. Indian 


Chiang HC, Ma YC, Huang KF. 1981. Quantitative analysis of citronella oil and lemongrass oil by hydrogen 

NMR spectrometry. Taiwan Yao Huesch Ta Chin 33: 95–103 (C.A. 97, 11630-j). 

Chicopharma NV. 1970. Pat. Neth. No. 6909123 (C.A. 7479503-a). 

Chisowa BH. 1997. Chemical composition of flower and leaf oils of Cymbopogon densiflorus Stapf from 

Zambia. J Essen Oil Res 9: 469, 470. 

Chopra RN, Nayar SL, Chopra IC. 1956. Glossary of Indian Medicinal Plants. CSIR, New Delhi, p. 87. 

Choudhary DK, Kaul BL. 1979. Radiation-induced methyl eugenol deficient mutant of Cymbopogon flexuosus 

(Nees ex Steud.) Wats. Proc Indian Acad Sci Sect 88 B: 225–228. 

Choudhary SN, Leclercq PA. 1995. Essential oil of Cymbopogon khasianus (Munro ex Hack.) Bor from north 

eastern India. J Essen Oil Res 7: 555, 556. 

Ciaramello D, Azzini A, Pinto AJD, Guilherme M, Donalisio R. 1972. Use of citronella, lemongrass, palmarosa 

and vetiver leaves for the production of cellulose and paper. An Acad Bras Cienc 44(Suppl.): 430–441. 

(C.A. 83, 8 1640-x). 

Crawford M, Hanson AW, Koker MES. 1975. Structure of Cymbopogon, a novel triterpenoid from lemongrass. 

Tetrahedron Lett 35: 3099–3102. 

Cronquits A. 1980. Chemistry in plant taxonomy, In Chemosystematics Principles and Practice. (Bisby FA, 

Vaughan JC, and Wright CA, Eds), Academic Press, London. pp. 1–27. 

Croteau R, Felton M, Karp F, Kjonaas R. 1981. Relationship of camphor biosynthesis to leaf development in 

sage (Salvia officinalis). Plant Physiol 67(4): 820–824. 

Croteau R, Davis EM. 2005. (−)-Menthol biosynthesis and molecular genetics. Naturwissenschaften 92: 

562–567. 

Crowell PL. 1999. Prevention and therapy of cancer by dietary monoterpenes. J Nutr 129: 775–778. 

Dawidar AM, Esmiraly ST, Abdel MM. 1990. Sequiterpenes from Cymbopogon schoenanthus. Pharmazie 45: 

296, 297.


De Martinez MV. 1977. Adaptation of the determination of citral with hydroxyl aminehydrochloride to lemongrass 

oil. Arch Bioquim Quim Farm 20: 51–56 (C.A., 91,181225-j). 

De Sylva MG. 1959. Lemongrass oil from Ceylon. Mfg Chemist 30: 415, 416. 

Dev Kumar C, Narayana MR, Khan MNA. 1977. Synthetic products from oil of citronella. Indian Perfumer 

22: 139–145. 

Dev V, Melander D, Yee JT. 1988. Terpenoid composition of the essential oil from Cymbopogon jwarancusa. 

Dev Food Sci Flav Frag 18: 317–321. 

Dhar AK, Lattoo S. 1985. Essential oil content in Cymbopogon jwarancusa after cutting. Pafai J 7: 28–31. 

Dhar AK, Thapa RK, Atal CK. 1981. Variability in yield and composition of essential oil in Cymbopogon 

jwarancusa. Planta Med 41: 386–388. 

Dhar RS, Dhar AK, 1997. Ontogenetic variation in essential oil concentration and its constituents in five genotypes 

of Cymbopogon jwarancusa (Jones) Schult. J Essen Oil Res 9: 433–439. 

Dikshit A, Hussain A. 1984. Anti-fungal action of some essential oils against animal pathogens. Fitoterapia 

55: 171–176. 

Duarte MCT, Leme EE, Delarmelina C, Soares AA , Figueira GM, Sartoratto A. 2006. Activity of essential oils 

from Brazilian medicinal plants on Escherichia coli. J Ethnopharmacol 111(2): 197–201. 

Dubey NK, Kishore N, Varma J, Lee SY 1997. Cytotoxicity of the essential oil of Cymbopogon citratus and 

Ocimum gratissimum. Indian J Pharm Sci 59: 263–264. 

Dubey NK, Takeya K, Itakawa H. 1997. Citral: A cytotoxic principle isolated from the essential oil of 

Cymbopogon citratus against 1388 leukaemia cells. Curr Sci 73: 22–24. 

Dunyan Xue, Maosen Song, Ning Chen, Yaozu Chen. 1992. Chemical ingredients of the essential oil of 

Cymbopogon distans. Gaoden Xoxiao Huaxue X. Xuebao 13: 1551, 1552. 

Eisenreich W, Rohdich F, Bacher A. 2001. Deoxyxylulose phosphate pathway to terpenoids. Trends Plant Sci 

6: 78–84. 

Eisenreich W, Sagner S, Zenk MH, Bacher A. 1997. Monoterpenoid essential oils are not of mevalonoid origin. 

Tetrahedron Lett 38: 3889–3892. 

Eisenreich W, Schwarz M, Cartayrade A, Arigoni D, Zenk MH, Bacher A. 1998. The deoxyxylulose phosphate 

pathway of terpenoid biosynthesis in plants and microorganisms. Chem Biol 5: R221–R223. 

Elagamal MH, Wolff P. 1987. A further contribution to the sesquiterpenoid constituents of Cymbopogon proximus. 

Planta Med 53: 293, 294. 

EI Tawil BAH, EI Beih FK. 1982. Study of volatile oil of Saudi Cymbopogon citratus D.C. and Cymbopogon 

schoenanthus (L). J Chin Chem Soc (Taipei) 30: 281, 282 (C.A. 100,39433). 

Eskandar EF, Won Jun H. 1995. Hypoglycaemic and hyperinsulinenic effect of some Egyptian herbs used for 

the treatment of diabetes mellitus (type II) in rats. Egypt J Pharm Sci 36: 334–341. 

Esmort H, David RH, Dudley IF. 1998. Volatile constituents of the essential oil of Cymbopogon citratus Stapf. 

grown in Zambia. Flav Frag J 13(1): 29, 30. 

Evans FE, Miller DW, Cairus T, Baddeley GV, Wen KB. 1982. 13 C NMR of naturally occurring substances, 

Part 74. Structure analysis of proximadiol (Cryptomeridiol) by 13 C NMR spectroscopy. Phytochemistry 

21: 855–858. 

Figueirinha A, Paranhos A, Pérez-Alonso JJ, Santos-Buelga C, Batista MT. 2008. Cymbopogon citratus leaves: 

Characterization of flavonoids by HPLC-PDA-ESI/MS/MS and an approach to their potential as a source 

of bioactive polyphenols. Food Chem 110(3): 718–728. 

Foda YH, Abdullah MA, Zaki MS, Mostafa MM. 1975. Identification of the volatile constituents of the Egyptian 

lemongrass oil. II. IR Spectroscopy. Nahrung 19: 395–400 (C.A.83, 1683 17-w). 

Formacek K, Kubeczka KH. 1982. Essential Oils Analysis by Capillary Chromatography and 13 C NMR 

Spectroscopy. John Wiley & Sons, New York. 

Fuji T, Furukawa S, Suzuki S. 1972. Compounded perfumes for toilet goods. Non-irritative compounded perfumes 

for soaps. Yukagaku 21: 904–908 (C.A. 78, 75786-e). 

Gagrade SK, Sri Vastava RD, Sharma OP, Maghe MN, Trivedi KC. 1990. Evaluation of some essential oil for 

antibacterial properties. Indian Perfumer 34: 204–208. 

Ganguly P, Singh KK, Bhagat SD, Upadhyay DN, Chauhan YS, Gupta NK, Singh HS. 1979. “RRLJOR-3-1970” 

an improved strain of Java citronella (Cymbopogon martinii). Phytochemistry 26: 183–185. 

Gaydou BM, Raudriamiharisoa RP. 1987. Hydrocarbon from the essential oil of Cymbopogon winterianus 

Jowitt. Indian Perfumer 23: 107–111. 

Gaydou BM, Raudriamiharisoa RP. 1987. Composition of palmarosa (cymbopogon martinii) essential from 

Madagascar. J Agric Food Chem 35(1): 62–66.


Gaydou EM, Raudriamiharisoa RP. 1986. Hydrocarbons from the essential oil of Cymbopogon martinii. 

Phytochemistry 26(1): 183–185. 

Gildemeister B, Hoffmann F. 1956. Die Artherischen Ole, Vol. IV. Akademie Verlag, Berlin, pp. 307–419. 

Gonzalo VF, Villarrubia MM. 1974. Essential oil of lemongrass in Tucuman, Int Congr Essen Oils, Allured 

Publishing, Oak Park, Ilinois. p. 110 (C.A.,84,49730-m). 

Gonzalo VF, Villarrubia MM. 1973. Essential oil of lemongrass in Tucuman. Arch Bioquim Quim Farm 18: 

51–57. 

Grace O, Yisak W, Ogunlana EO. 1984. Antibacterial constituents in the essential of cymbopogon citratus. 

(D.C) Sapf. Journal of Ethnopharmacology 12: 279–286. 

Guenther E. 1948. The Essential Oils. Vol. 1, Van Nostrand, London. pp. 232–236. 

Guenther E. 1950. The Essential Oils. Vol. IV, Van Nostrand, London. pp. 3–153. 

Guillaume KK, Honore KK, Isabella AG, Jacques H. 2006. Comparative effects of cymbopogon shoenanthus 

essential oil and piperitone on collasabuchus maculatur development. Fitoterapia 77(7–8): 506–510. 

Gulati BC, Sadgopal 1972. Chemical examination of oil of Cymbopogon nardus. Indian Oil Soap J 37: 

305–310. 

Gulati BC, Garg SN. 1976. Essential oil of Cymbopogon pendulus Wats. under the Tarai climate of Uttar 

Pradesh. Indian J Pharm 38: 78, 79. 

Gupta BK, Daniel P. 1982. Aromatic grasses of India and their utilization—a plea for further research. Pafai J 

Jan–March, 13–27. 

Gupta BK, Jam N. 1978. Cultivation and utilization of genus Cymbopogon in India. Indian Perfumer 21: 55–68. 

Gupta BK. 1969. Studies in the genus Cymbopogons. Perfum Essen Oil Res 70B: 241–247. 

Gupta PC, Singh R, Singh K, Pradhan K. 1975. Chemical composition and in vitro matter digestibility of some 

important grasses. Ann Arid Zone 14: 245–250 (C.A. 84, 178699-g). 

Gupta YN, Chauhan PNS. 1970. Effect of ultraviolet radiation on essential oils. Indian Perfumer 14: 63–66. 

Gyane DD. 1976. Preservation of shea butter. Drug Cosmet Ind 18: 36–38 and 138–140. 

Handique AK, Singh HB. 1990. Antifungal action of lemongrass oil on some soil-borne plant pathogens. Indian 

Perfumer 34: 232–234. 

Han IK, Kim KL, Park SH, Kim BH, Ahn BH. 1971. Nutritive values of the native grasses and legumes in Korea 

V. Chemical determination of the mineral content of native herbage plants. Han‘guk Chuksanak’hoe Chi 

13: 329–334 (C.A.81, 74938-f). 

Hanson SW, Crawford M, Koker MES, Menezes FA. 1976. Cymbopogonol: A new triterpenoid from C. citratus. 

Phytochemistry 15: 1074, 1075. 

Herath HMW, Iruthayathas EE, Ormrod DP. 1979. Temperature effects on essential oil composition of citronella 

selection. Econ Bot 33: 425–430. 

Herz S, Wungsintaweekul J, Schuhr CA, Hecht S, Lüttgen H, Sagner S, Fellermeier M, Eisenreich W, Zenk 

MH, Bacher A, Rohdich F. 2000. Biosynthesis of terpenoids: YgbB protein converts 4-diphosphocytidyl- 

2C-methyl-d-erythritol 2-phosphate to 2C-methyl-d-erythritol 2,4-cyclodiphosphate. Proc Natl Acad Sci 

USA 97: 2486–2490. 

Idrissi A, Bellakhdar J, Canigueral S, Iglesian J, Vila R. 1993 Composition of the essential oil of lemongrass 

(C. citratus D.C.) Stapf. cultivated in Morocco. Plantes Medicinales et Phytotherapie 24: 274–277. 

Ille K. 1986. Gas chromatographic analysis of some essential oils used in perfumery. Mezhdunar 4th Kongar 

Efirnym Maslam. Naumenko PV (Ed.), Moscow. pp. 112–123. 

Iruthayathas EE, Herath HMW, Wijesekara ROB, Jayawardene AL. 1997. Variations in the composition of oil 

in citronella. J Nat Sci Coun Sri Lanka 5: 133–146. 

Jirovetz L, Buchbauer G, Eller G, Ngassoum, MB, Maponmetsem PM. 2007. Composition and antimicrobial 

activity of Cymbopogon giganteus (Hochst.) Chiov. Essential flower, leaf and stem oils from Cameroon. 

J Essen Oil Res 19: 485–489. 

Jyrkit T. 1983. Composition of the essential oil of C. flexuosus. J Chrom 262: 364–366. 

Kalia NK, Sood RP, Padha CD, Jamwal RK, Chopra MM. 1980. Utilization of wild growing Cymbopogon 

martinii (var. sofia). Indian Perfumer 24: 182–184. 

Kamali HHEL, Hamza MA, Amir MYEL. 2005. Antibacterial activity of the essential oil from Cymbopogon 

nervatus inflorescence. Fitoterapia 76(5): 446–449. 

Kanjilal PB, Pathak MG, Singh RS, Ghosh AC. 1995. Volatile constituents of the essential oil of Cymbopogon 

caesius (Nees ex Hook. et Am) Stapf. J Essen Oil Res 7: 437–449. 

Kaul BL, Choudhary DK, Atal CK. 1977. Introduction and chemical evaluation of Burmese citronella in 

Jammu. Indian J Pharmacol 39: 42, 43.


Ketoh GK, Koumaglo HK, Glitho IA, Huignard J. 2006. Comparative effects of Cymbopogon schoenanthus 

essential oil and piperitone on Callosobruchus maculatus development. Fitoterapia 77(7–8): 506–510. 

Khadri A, Serralheiro MLM, Nogueira JMF, Neffati M, Smiti S, Araújo MEM. 2008. Antioxidant and 

antiacetylcholinesterase activities of essential oils from Cymbopogon schoenanthus L. Spreng. 

Determination of chemical composition by GC-mass spectrometry and 13 C NMR. Food Chem 

109(3): 630–637. 

Kichiyoshi Koryo KK, Akira Sangy KK. 1981. An unpleasant odour composition for prevention of thinner 

sniffing. Jpn Tokyo Koho JP Pat 48538 (C.A., 96, 117345-q). 

Kisaki A, Matsuyama Y, Sakano T, Fujiwara N, Nakaguchi O. 1998. Antimale sex hormone agent and composition. 

Jpn Kokai Tokyo JP 17: 486. 

Kokate CK, Verma KC. 1971. Antimicrobial activity of volatile oils of Cymbopogon nardus and Cymbopogon 

citratus. Sci Cult 37: 196–198. 

Koketsu M, Moura LL, Magalhaes MT. 1976. Essential oil of Cymbopogon densiflorus Stapf. and Tagetes 

minuta L. grown in Brazil. An Acad Bras Cienc 48: 743–746 (C.A.88, 141480-k). 

Kreis P, Masandl A. 1994. Chiral compounds of essential oil. Part XVII. Simultaneous stereoanalysis of 

Cymbopogon oil constituents. Flav Frag J 9: 257–260. 

Krishnamoorthy G, Kavimani S, Loganthan C. 1998. Antiinflammatory activity of the essential oil of 

Cymbopogon martinii. Indian J Pharm Sci 60: 114–116. 

Krishnarajah SR, Ganesalingam VK, Senanayake UM. 1985. Repellancy and toxicity of some plant oils and 

their terpene components to Stotroga cereallelia (Olivier). Trop Sci 25: 249–252. 

Kulkarni RN, Mallavarapu GR, Bhaskaran K, Ramesh S, Kumar S. 1997. Essential oil composition of citronella-like 

variant of lemongrass. J Essen Oil Res 9: 393–395. 

Kumar A, Malik F, Bhushan S, Sethi VK, Shahi AK, Kaur J, Taneja SC, Ghulam N, Qazi GN, Singh J. 2007. 

An essential oil and its major constituent isointermedeol induce apoptosis by increased expression of 

mitochondrial cytochrome c and apical death receptors in human leukaemia HL-60 cells. Chem-Biol 

Interact 171(3): 332–347. 

Kuriakose KP. 1995. Genetic variability in East Indian lemongrass (C. flexuosus Stapf.). Indian Perfumer 39: 

76–83. 

Kurian A, Nair BVG, Rajan KC. 1984. Effect of antioxidants on the preservation of citral content of lemongrass 

oil. Indian Perfumer 28: 28–32. 

Kusumov FY, Babaev RI. 1983. Components of the essential oil of Cymbopogon citratus. Stapf Khim Prir 

Soedin 1: 108–109 (C.A., 98 204188-a). 

Kuzuyama T, Takagi M, Kaneda K, Dairi T, Seto H. 2000. Formation of 4-(cytidine-5′-diphospho)-2-C-methyld-erythritol 

from 2-C-methyl-d-erythritol 4-phosphate by 2-C-methyl-d-erythritol 4-phosphate cytidylyltransferase, 

a new enzyme in the non-mevalonate pathway. Tetrahedron Lett 41: 703–706. 

Kuzuyama T, Takagi M, Kaneda K, Watanabe H, Dairi T, Seto H. 2000 Studies on the nonmevalonate pathway: 

conversion of 4-(cytidine-5′-diphospho)-2-C-methyl-d-erythritol to its 2-phospho derivative by 

4-(cytidine-5′-diphospho)-2-C-methyl-d-erythritol kinase Tetrahedron Lett 41: 2925–2928. 

Lange BM, Croteau R. 1999. Isoprenoid biosynthesis via a mevalonate-independent pathway in plants: cloning 

and heterologous expression of 1-deoxy-d-xylulose-5-phosphate reductoisomerase from peppermint. 

Arch Biochem Biophys 365: 170–174. 

Lange BM, Wildung MR, McCaskill DG, Croteau R. 1998 A family of transketolases that directs isoprenoid 

biosynthesis via a mevalonate-independent pathway. Proc Natl Acad Sci USA 95: 2100–2104. 

Lawrence BM. 1991. Citronella oil: A monograph. In Lawrence Review of Natural Products, p. I. 

Le KT, Chu PNS. 1976. Chemical composition of lemongrass essence (Cymbopogon flexuosus Stapf.) from 

Vietnam. Tap Clii Hoc 14: 31–36. 

Lemos TLG, Monte EJO, Matos FJA, Alencer JW, Craveiro AA, Barobasa RCSB, Lima BO. 1994. Chemical 

composition and antimicrobial activity of essential oils from Brazilian plants. Fitoterapia 63: 226–228. 

Lichtenthaler HK. 1999. Annu Rev Plant Physiol Plant Mol Biol 50: 47–66. 

Little DB, Croteau R. 1999. Biochemistry of essential oil terpenes: A thirty year overview. In Flavour Chemistry: 

Thirty Years of Progress (Hornstein I et al., Eds). Kluwer Academic/Plenum Press, New York. pp. 

239–253. 

Liu C, Zhang J, Yiao R, Gan L. 1981. Chemical studies on ten essential oils of Cymbopogon genus. Huaxue 

Xuebao 241–247 (C.A.98, 104358-in). 

Liu M, Feng G. 1989. Effect of Cymbopogon goeringii (Steud.) A. Camus volatile oil on physiological properties 

of isolated guinea pig myocardium. Zlionguo Zliongyao Zazlii 14: 160–622.


Lohani H, Bisht JC, Melkani AB, Mathela DK, Mathela CS, Dev V. 1986. Chemical composition of essential 

oil of Cymbopogon stracheyi (Hook f.) Riaz and Jani. Indian Perfumer 30: 447–452. 

Lorenzetti BB, Souza GEP, Sarti SJ, Santos ED, Frreira SH. 1991. Myrcene mimics the peripheral analgesic 

activity of lemongrass tea. J Ethnopharmacol 34: 43–48. 

Lorenzo D, Dellacassa E, Atti-Serafini L, Santos AC, Frizzo C, Paroul N, Moyna P, Mondello L, Dugo G. 2000. 

Composition and stereoanalysis of Cymbopogon winterianus Jowitt. oil from Southern Brazil. Flav 

Frag J 15(3): 177–181. 

Lucius G, Adler B. 1971. Mezhdunar Kangr. Effirnym Maslam (Mater) 4th, 1: 211–214. Naumenko PV, Ed., 

“Pishcheuaya, Promyshlennot,” Moscow, USSR (C.A. 78,15 1557-y). 

Lüttgen H, Rohdich F, Herz S, Wungsintaweekul J, Hecht S, Schuhr CA, Fellermeier M, Sagner S, Zenk MH, 

Bacher A, Eisereich W. 2000. Biosynthesis of terpenoids: YchB protein of Escherichia coli phosphorylates 

the 2-hydroxy group of 4-diphosphocytidyl-2C-methyl-d-erythritol. Proc Natl Acad Sci USA 97: 

1062–1067. 

Maheshwari ML, Chandel KPS, Chien MJ. 1988. The composition of essential oil from Hyssopus officinalis 

and Cymbopogon jwarancusa (Jones) Schult. collected in the cold desert of Himalaya. Dev Food Sci Flav 

Frag 18: 171–176. 

Maheshwari ML, Mohan J. 1985. Geranyl formate and other esters in palmarosa oil. Pafai J 7: 21–26. 

Mallavarapu GR, Kulkami RN, Ramesh S. 1992a. Composition of the essential oil of Cymbopogon coloratus. 

Planta Med 58: 479, 480. 

Mallavarapu GR, Ramesh S, Kulkami RN, Shyamsunder KV. 1992b. Composition of essential oil of Cymbopogon 

travencorensis. Planta Med 58: 219–222. 

Mallavarapu GR, Rajeshwara Rao, Kaul PN, Ramesh S, Bhattacharya AK. 1998. Volatile constituents of the 

essential oil of the seeds and the herb of palmarosa (C.martinii (Roxb.) Wats. var. motia Burk. Flav 

Frag J 13: 161–169. 

Manjoor-i-Khuda M, Rahman M, Yusuf M, Choudhary J. 1984. Essential oils of Cymbopogon species of 

Bangladesh. J Bangladesh Acad Sci 8: 77–80. 

Manjoor-i-Khuda M, Rahman M, Yusuf M, Choudhary J. 1986. Studies on essential oil bearing plants of 

Bangladesh. Part II. Five species of Cymbopogon from Bangladesh and the chemical constituents of their 

essential oils. Bangladesh J Sci Ind Res 21: 70–82. 

Mathela CS, Joshi P. 1981. Terpenes from the essential oil of Cymbopogon distans. Phytochemistry 20: 2770, 

2771. 

Mathela CS, Melkani AB, Pant AK, Pande C. 1988a. Chemical variations in Cymbopogon distans and their 

chemosystematic implications. Biochem Syst Ecol 16:161–165. 

Mathela CS, Chittattu GI, Thomas J. 1996. OD-468. A Lemongrass chemotype rich in geranyl acetate. Indian 


Mathela CS, Lohani H, Pande C, Mathela DK. 1988. Chemosystematics of terpenoids in Cymbopogon martini. 

Biochem Syst Ecol 16: 167–169. 

Mathela CS, Melkani AB, Pant AK, Vasu Dev, Nelson TE, Hope H, Bottini AT. 1989. Eudesmanediol from 

Cymbopogon distans. Phytochemistry 28: 1936–1938. 

Mathela CS, Pande C, Pant AK, Singh AK. 1990a. Terpenoid composition of Cymbopogon distans f. munsiyariensis. 

Herb Hung 27: 117–121. 

Mathela CS, Pande C, Pant AK, Singh AK. 1990b. Phenylpropanoid constituents of Cymbopogon micro stachys. 

J Indian Chem Soc 67: 526–528. 

Mathela CS, Pant AK, Melkani AB, Pant A. 1986. Aromatic grasses of U.P Himalaya: A new wild species as a 

source of aroma chemicals. Sci Cult 52: 342–344. 

Mathela CS, Pant AK. 1988. Production of essential oils from some new Himalayan Cymbopogon species. 


Mathela CS, Sinha GK. 1978. Study of the essential oil of C. nardus var. stracheyi. J Indian Chem Soc 55: 

621, 622. 

Mathela CS. 1991. Flavour constituents of Himalayan aromatic grasses. International Symposium on Newer 

Trends in Essential Oils and Flavours, RRL Jammu, India, p. 27. 

Mehmood Z, Ahmad S, Mohammed F. 1997. Antifungal activity of some essential oils and their major constituents. 

Indian J Nat Products 13: 10–13. 

Melkani AB, Joshi P, Pant PK, Mathela CS, Dev V. 1985. Constituents of the essential oil from two varieties of 

Cymbopogon distans. J Nat Prod 46: 1995–1997. 

Menon TCK. 1956. The essential oil of Cymbopogon travancorensis. J Bombay Nat Hist Soc 53: 742, 743.


Modawi BM, Magar HRY, Satti AM, Duprey RJH. 1984. Chemistry of Sudanese flora. Part III. Cymbopogon 

nervatus. J Nat Prod 47: 167–169. 

Mohammad F, Nigam MC, Rehman W. 1981a. Detection of new trace constituents in the essential oils of 

Cymbopogon flexuosus. Pafai 13: 22–24. 

Mohammad F, Nigam MC, Rehman W. 1981b. Essential oil of Cymbopogon martinii var. motia: detection of 

new trace constituents. Pafai J 3: 11–13. 

Moody JO, Adeleye SA, Gundidza MG, Wyllie G, Ajayi-Obe OO. 1995. Analysis of the essential oil of 

Cymbopogon nardus (L.) Rendle growing in Zimbabwe. Pharmazie 50(1): 74, 75. 

Moris JA, Khettry A, Seitz EW. 1979. Antimicrobial activity of aroma chemicals and essential oils. J Am Oil 

Chem Soc 56: 595–603. 

Muthuswami S, Sayed S. 1980. Preliminary note on the extraction of lemongrass oil. Indian Perfumer 24: 226, 

227. 

Naik SN, Kumar A, Maheshwari RC, Kumar B, Chandra R, Guddewar MB. 1995. Evaluation of toxicity and 

growth-inhibiting activity of Tripolium castaneum (Herbst). Indian Perfumer 39: 1–8. 

Nair BVG, Chinnamma NP, Pushpakumari R. 1980a. Influence of varieties on the grass, oil yield and quality 

of oil of palmarosa (C. martinii Stapf. var. motia). Indian Perfumer 24: 22–24. 

Nair BVG, Chinnamma NP, Pushpakumari R. 1980b. Investigations on some types of lemongrass (C. flexuosus 

Stapf.) Indian Perfumer 24: 20, 21. 

Nair EVG, Mariam KA. 1978. The new promising aromatic plant of Kerala. Indian Perfumer 22: 300, 301. 

Nair RV, Siddiqui MS, Sen T, Nigam MC. 1982. Identification of three new species of Cymbopogon in perfumery 

value and their G.C. evaluation. Pafai J 4: 21–23. 

Namba T, Hatsutori Y, Shimomoura K, Nakamura M. 1995. Extraction of hyalurodinase inhibitors from 

Azadirachta indica or other plants for manufacturing cosmetics or for therapeutic use. Japan Kokai Tokai 

Tokyo Koho JP 07, 138,180 (95,138,180). 

Nath SC, Saha BN, Bordoloi DN, Mathur RK, Leclercq PA. 1994. The chemical composition of the essential 

oil of Cymbopogon flexuosus Steud. Wats. growing in northeast India. J Essen Oil Res 6: 85–87. 

Naves YR. 1970. Palmarosa oil compounds. Parfum Cosmet Savons 13: 354–357 (C.A.73, 59212–6). 

Naves YR. 1971. Components of palmarosa essential oil. In Meijhdunar Kongr. Efirnym Maslam (Mater), 

4th, 1: 239–244. Naumenko PV, Ed., “Pishchevaya Promyshlennost”, Moscow, USSR (C.A. 78, 16393 

1-d). 

Newman JD, Chappell J. 1999 Isoprenoid biosynthesis in plants: carbon partitioning within the cytoplasmic 

pathway. Crit Rev Biochem Mol Biol 34: 95–100. 

Neyberg AG. 1953. Some essential oil from the east of the colony. Bull Agr Conogo 44: 1–38 and 319–364 

(C.A. 48, 957-d). 

Ng TT. 1972. Growth performance and production potential of some aromatic grasses in Sarawak, Preliminary 

assessment. Trop Sci. 14: 47–58. 

Nigam MC, Datta SC, Bhattacharya AK, Duhan SPS. 1975. Utilization of citral rich oils for production of 

geraniol. Indian Perfumer 18: 55, 56. 

Nigam MC, Nigam IC, Levi L. 1965. Essential oil and their constituents XXVII: Composition of gingergrass. 

Can J Chem 43: 521–525. 

Nigam MC, Srivastava HK, Siddiqui MS. 1987. Chemistry of Cymbopogon and their essential oils. Pafai 19: 

13–20. 

Olaniyi AA, Sofowora EA, Oguntimehin BO. 1975. Phytochemical investigation of some Nigerian plants used 

against fevers II. Cymbopogon citratus. Planta Med 28: 186–189. 

Oliveros-Belardo L, Aureus B. 1978. Essential oil from C. citratus (D.C.) Stapf. growing in the Philippines. 

Asian J Pharm 3: 14–17 (C.A.90, 15698 1-q). 

Oliveros-Belardo L, Aureus E. 1979. Essential oil from Cymbopogon citrates (D.C.) Stapf. growing wild in the 

Phillippines. Int Congr Essential Oils. 7: 166–168 (C.A. 92, 37768-g). 

Oliveros-Belardo L, Smith RM, Gupta ZB, Abadiano MJP. 1989. Leaf essential oil of wild Cymbopogon martinii 

(Roxb.) Wats. from Sorsogon, Philippines. Philippine J Sci 118: 31–58. 

Onawunmi GO, Yisak W, Ogunlana EO. 1984. Antibacterial constituents in the essential oil of Cymbopogon 

citratus (DC.) Stapf. J Ethnopharmacol 12(3): 279–286. 

Opdyke DLJ. 1973. Monographs on fragrance raw materials: Caryophyllene. Food Cosmet Toxicol 11: 

1059–1060. 

Opdyke DLJ. 1974. Monographs on fragrance raw materials: Palmarosa oil. Food Cosmet Toxicol 12 (Suppl.): 

947. 

Opdyke DLJ. 1976. Inhibition of sensitization reactions induced by certain aldehydes. Food Cosmet Toxicol 

14: 197, 198.


Opdyke DLJ. 1976. Monographs on fragrance raw materials: Lemongrass oil: East Indian. Food Cosmet Toxicol 

14: 455. 

Opdyke DLJ. 1976. Monographs on fragrance raw materials: Lemongrass oil: West Indian. Food Cosmet 

Toxicol 14: 457. 

Orafidiya LO. 1993. The effect of autoxidation of lemongrass oil on its antibacterial activity. Phytotherapy Res 

7: 269–271. 

Osmani S, Anees I, Naidu MB. 1972. Insect repellent creams from essential oils. Pesticides 6: 19–21. 

Oyedele AO, Gbolade AA, Sosan MB, Adewoyin FB, Soyelu OL, Orafidiya OO. 2002. Formulation of an effective 

mosquito-repellent topical product from lemongrass oil. Phytomedicine 9(3): 259–262. 

Pande C, Melkani AB, Mathela CS. 1997. Cymbopogon distans: report on new chemotype. Indian Perfumer 

41: 35, 36. 

Pandey MC, Sharma lR, Dikshit A. 1996. Antifungal evaluation of the essential oil of Cymbogon pendulus 

(Nees ex Steud) Flav Frag J 11: 257–260.. 

Pandey TC, Gupta YN. 1973. Effect of γ-radiations on citronella oils (Ceylon type). Indian Perfumer 17: 18, 19. 

Pant AK, Mathela CS, Pande N, Pant AK. 1990. Phenyl propenoid constituents of Cymbopogon microstachys 

J Indian Chem Soc 67: 526, 527. 

Patra NK, Singh HP, Kalra A, Singh HB, Mengi N, Singh VR, Naqvi AA, Kumar S. 1997. Isolation and development 

of geraniol-rich cultivar of citronella (C. winterianus). J Med Arom Plant Sci 19: 672–676. 

Patra NK, Srivastava RK, Chauhan SP, Ahmad A, Misra LN. 1990. Chemical features and productivity of a 

geraniol-rich variety (GRL-1) of Cymbopogon flexuosus. Planta Med 56: 239, 240. 

Patra P, Dutta PK. 1986. Evaluation of improved lemongrass strains for herb and oil yield and citral content 

under Bhubaneswar condition. Res Ind 31: 358–360. 

Peyron L. 1972. Essence produced in Mata Grasse. An Acad Bras Cienc 44 (Suppl.): 332–340 (C.A. 83, 136686-z). 

Peyron L. 1973. Essential oil from Mato Grasso. Perftimes Cosmet Savons 3: 371–378. 

Pilley PP, Rao P, Sanjiva B, Simonson JL. 1928. Constituents of some Indian essential oils, Part XXII. The 

essential oil from flower heads of C. coloratus Stapf. J lndian lnst Sci IIA: 181–186. 

Pino IA, Rosada A, Correa MT. 1996. Chemical composition of the essential oil of Cymbopogon winterianus 

Jowitt from Cuba. J Essen Oil Res 8: 693, 694. 

Popielas L, Moulis C, Keita A, Fouraste I, Bessiere IM. 1991. The essential oil of Cymbopogon giganteus. 

Planta Med 57: 586, 587. 

Prasad S, Jamwal R. 1971. Insecticidal composition. Indian Pat. 122,504 (C.A. 77, 30347-a). 

Quintans-Júnior LJ, Souza TT, Leite BS, Lessa NMN, Bonjardim LR, Santos MRV, Alves PB, Blank AF, 

Antoniolli AR. 2008. Phythochemical screening and anticonvulsant activity of Cymbopogon winterianus 

Jowitt. (Poaceae) leaf essential oil in rodents. Phytomedicine 15(8): 619–624. 

Rabha LC, Baruah AKS, Bordoloi DN. 1979. Search for aroma chemicals of commercial value from plant 

resources of North East India. Indian Perfumer 23: 178. 

Rabha LC, Hagarika AK, Bordoli DN. 1986. Cymbopogon khasianus, a new rich source of methyl eugenol. 


Rabha LC, Hazarika AK, Bordoloi. 1989. A chemotype of Cymbopogon khasianus (Hack.) Stapf. ex Bor: An 

additional information for a source of higher oil and geraniol from North India. Indian Perfumer 33: 

261–265. 

Rajapakse RHS, Jayasena W. 1991. Plant resistance and biopesticides from lemongrass oil for suppressing 

Spodoptera litura in peanut. Agri Int 43: 166, 167. 

Rajendrudu G, Rama Das VS. 1983. Interspecific differences in the constituents of essential oil of Cymbopogon. 

Proc Indian Acad Sci 92: 331–334. 

Ramdan FM, EI-Zanfaly HT, Allian AM, EI-Wakeil FA. 1972a. Antibacterial effects of some essential oils I. 

Chem Microbiol Technol Lebensm 1: 96–102 (C.A. 77, 122532-k). 

Ramdan FM, El-Zanfaly HT, Allian AM, El-Wakeil FA. 1972b. Antibacterial effects of some essential oils II. 

Chem. Microbiol Technol Lebensm 2: 51–55 (C.A. 77. 122533-m). 

Ramirez AR, Bressani R, Elias LG. 1977. Utilization of lemongrass Cymbopogon species begasse in ruminant 

nutrition. Int. Symp Feed Compas Anim Nutr Requir Comput Diets 198–203 (C.A. 91, 90167-r). 

Ranaweera SS, Dayananda KR. 1997. Mosquito-larvicidal activity of Ceylon citronella (C. nardus L.) Rendle 

oil fractions. J Nat Sci SriLanka 24: 247–252. 

Rao BGV, Narsimha JPL. 1971. Activity of some essential oils towards phytopathogenic fungi. Riechst. Aromen 

Koerperflegen 21: 405, 406 and 408–410 (C.A. 76, 81621-x). 

Rao BL, Kala S, Dhar KL, Kaul BS. 1992. New aromatic chemicals in Cymbopogon for future. Indian Perfumer 

36: 241–245.


Rao BN, Pandita S, Kaul BL. 1995. Gamma radiation as a mean of inducing variation in Cymbopogon flexuosus 

a chemotype for α-bisabolol Indian Perfumer 39: 84–87. 

Rao BS, Sudborough JJ. 1925. Kachi grass oil. J Indian Inst Sci 8A: 9–27. 

Rao JJ, Grover GS, Saxena VD. 1989. Mutagenic property of Cymbopogon martinii essential oil. Parfum 

Kosmet 70: 488. 

Rao JS. 1957. Grass flora of Coimbatore district, South India, J Bombay Nat Hist Soc 54: 674–690. 

Rauber CS, Guterres SS, Schapoval EES. 2005. LC determination of citral in Cymbopogon citratus volatile oil. 

J Pharm Biomed Anal 37(3): 597–601. 

Razdan TK, Koul GL. 1973. Chromatographic studies of Indian essential oils: Oil of Citronella Java type III. 

Indian J Chem 8: 27–32. 

Razdan TK.1984. Calorimetric analysis of the constituents of essential oils. Parfum Kosmet 65: 190–195. 

Rizk AM, Heiba HI, Mashaly M, Sandra P. 1985. Constituents of plants growing in Qatar. X . Seasonal variations 

of the volatile oil of Cymbopogon parkeri. Qatar Univ Sci Bull 5: 71–76 (C.A. 106, 2908h). 

Rizk AM, Heiba HI, Sandra P, Mashaly M, Bicchi C. 1983. Constituents of the volatile oil of Cymbopogon 

parkeri. J Chrom 279: 145–150. 

Rizk AM, Rimpler H, Ghaleb H, Heiba HI. 1986. Constituents of plants growing in Qatar. IX. The antispasmodic 

components of Cymbopogon parkeri Stapf. Int J Crude Drug Res 24: 69–74. 

Rohdich F, Wungsintaweekul J, Fellermeier M, Sagner S, Herz S, Kis K, Eisenreich W, Bacher A, Zenk MH. 

1999. Cytidine 5′-triphosphate-dependent biosynthesis of isoprenoids: YgbP protein of Escherichia 

coli catalyzes the formation of 4-diphosphocytidyl-2-C-methylerythritol. Proc Natl Acad Sci USA 96: 

11758–11763. 

Rohdich F, Wungsintaweekul J, Lüttgen H, Fischer M, Eisenreich W, Schuhr CA, Fellermeier, M, Schramek 

N, Zenk MH, Bacher A. 2000. Biosynthesis of terpenoids: 4-Diphosphocytidyl-2-C-methyl-d-erythritol 

kinase from tomato. Proc Natl Acad Sci USA 97: 8251–8256 (First Published July 4; 10.1073/ 

pnas.140209197). 

Rohmer M. 1999. The discovery of a mevalonate-independent pathway for isoprenoid biosynthesis in bacteria, 

algae and higher plants. Nat Prod Rep 16: 565–574. 

Rouesti P, Voriate G. 1960. Lemongrass extract in Italian Somali Land. Fr Parf 3: 39–44 (C.A. 55, 7765-b). 

Rout PK, Sahoo S, Rao YR. 2005. Essential oil composition of Cymbopogon microstachys (Hook.) Soenarke 

occurring in Manipur. J Essen Oil Res 17: 358–360. 

Saeed T, Sandra PJ, Verzele MJE. 1978. Constituents of the essential oil of Cymbopogon jwarancusa. 

Phytochemistry 17(8): 1433, 1434. 

Sangwan NK, Verma KK, Verma BS, Malik MS, Dhinsa KS. 1985. Nematicidal activity of essential oil of 

Cymbopogon grasses. Nematologica 31: 93–99. 

Sarer E, Scheffer JJC, Svendsen AB. 1983. Composition of the essential oil of Cymbopogon citratus Stapf. 

cultivated in Turkey. Sci Pharm 51: 58–63 (C.A. 99, 10685-k). 

Sargenti SR, Lancas FM. 1997. Supercritical fluid extraction of Cymbopogon citratus. Chromatographia 46: 

285–290. 

Schwander J, Müller C, Zeidler J, Lichtenthaler HK. 1999. Cloning and heterologous expression of a cDNA 

encoding 1-deoxy-D-xylulose-5-phosphate reductoisomerase of Arabidopsis thaliana. FEBS Lett 455: 

140–144. 

Selvag E, Holm IO, Thune P. 1995. Allergic contact dermatitis in an aroma therapist with multiple sensitization 

to essential oils. Contact dermatitis 33: 354, 355. 

Shadab-Qamar E, Hanif M, Choudhary FM. 1992. Antifungal activity of lemongrass essential oils. Pakistan J 

Sci Ind Res 35: 246–249. 

Shahi AK, Sen DN. 1993. Essential oil yielding grasses of the Indian Thar desert. Agric Equip Int 45: 62–65. 

Shahi AK, Sen DN, Mathela CS. 1990. Chemical studies on Cymbopogon schoenanthus (Linn). Spreng a grass 

of Indian Thar desert. Indian Drugs 28: 37, 38. 

Shahi AK, Sen DN. 1989. Note on Cymbopogon jwarancusa (Jones) Schult: Source of piperitone in Thar desert. 

Curr Agric 13: 99–101. 

Shahi AK, Sharma SN, Tava A. 1997. Composition of Cymbopogon pendulus (Nees ex Steud.) Wats., an elemicin 

rich oil grass grown in Jammu region of India. J Essen Oil Res 9: 561–563. 

Shahi AK, Tava A. 1993. Essential oil compositions of three Cymbopogon species of Indian Thar desert. J Essen 

Oil Res 5: 639–343. 

Shahi AK. 1992. A search of Cymbopogon jwarancusa (Jones) Schult. subsp. olivieri (Boiss.) Soenakro. A 

citral yielding grass from Indian Thar desert. Indian Perfumer 36: 182–184. 

Sharma ML, Pandey MB, Khanna KR, Kapoor LD. 1972. Essential oils from plants raised on alkaline soil. 

Indian Perfumer 16: 27–30.


Sharma ML, Srivaastava GS, Singh A. 1980. Essential oil from C. olivieri (Boiss.) Bor.). Indian Perfumer 24: 

17–19. 

Sharma PR, Mondhe DM, Muthiah S, Pal HC, Shahi AK, Saxena AK, Qazi GN. 2009. Anticancer activity of an 

essential oil from cymbopogon flexosus Chemica Biological Interactions 179(2–3): 160–168. 

Shaw DW. 1971. Roll-on insect repellent. Can Pat. 865069 (C.A.74: 140098-d). 

Shrivastava S, Rothria A, Misra N. 1990. Evaluation of essential oil of Cymbopogon martinii (Roxb.) Wats. for 

the control of Fusarium oxysporurn f. sp. udum casual organism of wilt of Arhar (Cajnus cajon). J Nat 

Acad Sci India 60B: 291, 292. 

Shylaraj KS, Thomas J. 1992. Effect of irradiation on the oil content of palmarosa (C. martinii var. motia). 


Siddique-Ullah M, Haque MM, Kalimuddin M. 1979. Dissolving pulp from lemongrass stem (C. flexuosus 

Linn.) by prehydrolysis Kraft process. Bangladesh J Sci 14: 359–361. 

Siddiqui MS, Mishra LN, Nigam MC, Abu-AI-Futuh, IM. 1980. Chemotaxonomie von Cymbopogon: Gas 

chromatographische untersuchung des etherischem oil von Cymbopogon proximus. Parfum Kosmet 61: 

419, 420. 

Siddiqui MS, Mohammad F, Srivastava SK, Gupta RK. 1979. A thin layer chromatographic method for estimation 

of geraniol in oils of palmarosa. Perfum Flavorist 4: 19, 20. 

Siddiqui MS, Sen T, Nigam MC, Datta SC. 1975. Isolation of alcoholic constituents of the oil of citronella 

(Java) by sodium complex method. Parfum Kosmet 56: 193, 194. 

Siddiqui N, Garg SC. 1990. In vitro anthelmintic activity of some essential oils. Pak J Sci Ind Res 33: 536, 

537. 

Singh A, Balyan SS, Shahi AK. 1978. Harvest management studies and yield potentiality of Jammu lemongrass. 


Singh AK, Dikshit A, Sharma ML, Dixit SN. 1980. Fungitoxic activity of some essential oils. Econ Bot 34: 

186–190. 

Singh AK, Naqvi AA, Ram G, Singh K. 1994. Effect of bay storage on oil yield and quality of three Cymbopogon 

species (C. winterianus, C. martinii, and C. flexuosus) during different harvesting seasons. J Essen Oil 

Res 6: 289–294. 

Singh AK, Ram G, Sharma S. 1996. Accumulation pattern of important monoterpenes in the essential oil of 

citronella Java (C. winterianus) during one year of crop growth. J Med Arom Plant Sci 18: 883–887. 

Singh AP, Sinha GK. 1976. Study of essential oil of C. distans Linn. Wats. Indian Perfumer 20: 67–70. 

Singh RS, Pathak MG. 1994. Herb yield and volatile constituents of cymbopogon jwaranusa (Jones) Schult 

cultivars. Industrial Crops and Products 2(3): 197–199. 

Singh RS, Pathak MG, Singh KK. 1970. Dynamics and diurnal changes in oil of Java citronella (C. winterianus 

Jowitt). Indian Perfumer 23: 116–120. 

Sinha AK, Mehra MS. 1977. Study of some aromatic medicinal plants. Indian Perfumer 22: 129–131. 

Sobti SN, Bradu BL, Rao BL, Verma V, Jamwal PS. 1978a. Search for aroma chemicals of industrial value from 

the genus Cymbopogon Pt. VI. C. khasianus from Arunanchal Pradesh—a new source of citral. Indian 

Perfumer 22: 222, 223. 

Sobti SN, Rao BL, Jani BB. 1978b. Genetic variability in oils of Cymbopogon: Scope for evolving new strains. 


Sobti SN, Rao BL, Pushpangadan P, Verma V. 1978c. Investigations in some newly introduced Cymbopogon 

species. Indian Perfumer 22: 278–280. 

Sobti SN, Rao BL, Sharma SN, Atal CK. 1981. Jamrosa, a new geraniol rich Cymbopogon. Indian Perfumer 

25: 116–118. 

Sobti SN, Verma V, Rao BL. 1982. Scope for development of new cultivars of cymbopogons as a source of terpene 

chemicals. In Cultivation and Utilization of Aromatic Plants (Atal CK, Kapur BM, Eds), Regional 

Reasearch Laboratory, Jammu, India. 

Soulari M, Fanghaenel E. 1971. Essential oil of C. winterianus (citronella oil) produced in Cuba. Rev Cenic 

Cienc Fis. 3: 79–91. 

Sprenger GA, Schörken U, Wiegert T, Grolle S, De Graaf AA, Taylor SV, Begley TP, Bringer-Meyer S, Sahm H. 

1997. Identification of a thiamin-dependent synthase in Escherichia coli required for the formation of the 

1-deoxy-d-xylulose 5-phosphate precursor to isoprenoids, thiamin, and pyridoxol. Proc Natl Acad Sci 

USA 94: 12847–12862. 

Srikulvandhana S, Jennings WG, Derafols W. 1976. Lemongrass oil from mutant clones of Cymbopogon flexuosus. 

Chem Mikrobiol Technol Lebensm 4: 129–131. 

Sukari MA, Rahmani M, Manas A, Takahashi S. 1992. Toxicity studies of plants extracts on insects and fish 

Partanika 15: 41–44.


Syeed M, Khalid MR, Choudhary FM. 1990. Essential oil of Gramineae family having antibacterial activity. 

Part I. C. citratus, C. martinii, C. jwarancusa oils. Pak J Sci Ind Res 33: 529–531. 

Takahashi S, Kuzuyama T, Watanabe H, Seto H. 1998. A 1-deoxy-d-xylulose 5-phosphate reductoisomerase 

catalyzing the formation of 2-C-methyl-d-erythritol 4-phosphate in an alternative non-mevalonate pathway 

for terpenoid biosynthesis. Proc Natl Acad Sci USA 95: 9879–9884. 

Talat S, Patrick JS, Maurice JEV. 1978. Constituent of the essential oil of cymbopogon jwarancusa. Phytochemistry 

17(8): 1433–1434. 

Taskinen J, Mathela DK, Mathela CS. 1983. Composition of the essential oil of Cymbopogon flexuosus. 

J Chromatogr 262: 364–366. 

Thapa RK, Agarwal SG, Dhar KL, Atal CK. 1981. Citral containing Cymbopogon species. Indian Perfumer 

25: 15–18. 

Thapa RK, Agarwal SK. 1989. Cymbopogon flexuosus: A rich source for (±) α-bisabolol. J Essen Oil Res 

107–110. 

Thapa RK, Bradu BL, Vashist VN, Atal CK. 1971. Screening of Cymbopogon species for useful constituents. 

Flav Industry 2: 49–51. 

Thapa RK, Dhar KL, Atal CK. 1976. The essential oil of Cymbopogon flexuosus RRL-57 and RRL-59, Part II. 


Thieme H, Benecke R, Brotka J. 1980. Application of gas chromatography in determining the constituents 

of Oleam citronella. Zentralbl Pharm Pharmakother Laboratoriums Diagn 119: 953–957 (C.A. 94, 

36417-w). 

Torres RC, Ragadio AG. 1992. Chemical composition of the essential oil of Philippines Cymbopogon citratus 

D.C Stapf. The Asian symposium of Medicinal Plants, Spices and other Natural Products (ASOMAS 

VII), Manila, 2–7 February. 

Torres RC, Ragodio AG. 1996. Chemical composition of the essential oil of Philippine Cymbopogon citratus 

(D.C.) Stapf. Philippine J Sci 125: 147–156. 

Torres RC. 1993. Citral from Cymbopogon citratus (D.C.) Stapf. lemongrass oil. Philippine J Sci 122: 269–278. 

Verma V, Sobti SN, Atal CK.1987. Chemical composition and inheritance pattern of five Cymbopogon species. 


Vijender SM, Mohammed A. 2002. Volatile constituents of Cymbopogon nardus (Linn.) Rendle. Flav Frag J 

18(1): 73–76. 

Virmani OP, Datta SC. 1973. Scope of production of some essential oil in the Lucknow district. Indian Perfumer 

17: 35–41. 

Virmani OP, Datta SC. 1971. Essential oil of Cymbopogon winterianus (oil of citronella). Flav Ind 2: 595–602. 

Vole CD, Baeta J, Antonio P da Cunha. 1997. Comparative chemical study of inflorescence of Cymbopogon 

gigariteum. Bot Esc Farm Univ Coimbra Ed Cient 27: 17–52. 

Wannissom B, Jarikasen S, Soontorn TT. 1996. Antifungal activity of lemongrass oil and lemongrass oil cream. 

Phytother Res 10: 551–554. 

Wijesekera ROB, Jayewardene AL, Foneska BD. 1973a. Varietal difference in the constituents of citronella oil. 

Phytochemistry 12: 2697–2704. 

Wijesekera ROB, Jayewardene AL, Foneska BD. 1973b. The chemical composition and analysis of citronella 

oil. J Nat Sci Coun Sri Lanka 1: 67–81 (C.A. 81.111382-t). 

Yadav P, Dubey NK. 1994. Screening of some essential oils against ring worm fungi. Pharma Sci 56: 

227–230. 

Zaki MSA, Foda YH, Mustafa MM, Abd Allah MA. 1975. Identification of the volatile constituents of the 

Egyptian lemongrass oil II. Thin layer chromatography. Nahrung 19: 201–205. 

Zamureenka VA, Klyuev NA, Grandberg IH, Dmitriev LB, Esvandghya GA. 1981. Composition of essential oil 

of lemongrass (C. citratus D.C.). Izv Timiryazensk S-Kh Akad 2: 167–169 (C.A. 94, 145166-j). 

Zheng GQ, Kenney PM, Tam TDT. 1993. Potential anticarcinogenic natural products isolated from lemongrass 

oil and galanga root oil. J Agric Food Chem 41: 153–156.

3 

contents 

The Cymbopogons 

Harvest and Postharvest 

Management 

A. K. Pandey 

3.1 Introduction .......................................................................................................................... 108 

3.2 Lemongrass ........................................................................................................................... 109 

3.2.1 Harvesting ................................................................................................................. 109 

3.2.2 Yield .......................................................................................................................... 112 

3.2.3 Postharvest Management .......................................................................................... 112 

3.2.3.1 Predistillation Handling ............................................................................. 112 

3.2.3.2 Drying ........................................................................................................ 113 

3.2.3.3 Storage ....................................................................................................... 113 

3.2.3.4 Distillation ................................................................................................. 113 

3.2.3.5 Supercritical Fluid Extraction (SFE) ......................................................... 115 

3.2.3.6 Treatment of Oil Prior to Storage .............................................................. 116 

3.2.4 Quality Analysis ....................................................................................................... 116 

3.2.4.1 Standard Specifications .............................................................................. 117 

3.3 Palmarosa (Cymbopogon martinii var. motia (Roxb.) Wats.) ............................................... 117 

3.3.1 Uses ........................................................................................................................... 118 

3.3.2 Harvesting ................................................................................................................. 118 

3.3.3 Storage ...................................................................................................................... 119 

3.3.4 Yield .......................................................................................................................... 119 

3.3.5 Distillation ................................................................................................................120 

3.3.6 Oil Storage ................................................................................................................120 

3.3.7 Oil Content and Yield ...............................................................................................120 

3.3.8 Standard Specifications ............................................................................................ 121 

3.4 Citronella (Cymbopogon winterianus Jowitt) ....................................................................... 121 

3.4.1 Harvesting ................................................................................................................. 122 

3.4.2 Storage of C. winterianus Hay .................................................................................126 

3.4.3 Yield ..........................................................................................................................126 

3.4.4 Distillation Procedure ...............................................................................................126 

3.4.5 Standard Specifications ............................................................................................126 

3.5 Jamrosa (Cymbopogon nardus Rendle) ................................................................................ 127 

3.5.1 Uses ........................................................................................................................... 127 

3.5.2 Harvesting ................................................................................................................. 127 

3.5.3 Distillation ................................................................................................................128 

3.5.4 Yield ..........................................................................................................................128 

3.6 Conclusion ............................................................................................................................128 

References ...................................................................................................................................... 129 

107



Cymbopogon (Poaceae) represents an important genus of about 120 species that grow in tropical 

and subtropical regions around the world. On account of their diverse uses in pharmaceutical, 

cosmetics, food and flavor, and agriculture industries, Cymbopogon grasses are cultivated (medicultured) 

on a large scale, especially in the tropics and subtropics. There is a large worldwide demand 

for the essential oils of Cymbopogon species (Dutta 1982; Gunther 1956). They are well known as 

a source of commercially valuable compounds such as geraniol, geranyl acetate, citral (neral and 

geranial), citronellal, piperitone, eugenol, etc., which are either used as such in perfumery and allied 

industries or as starting materials for the synthesis of other products commonly used in perfumery 

(Shahi and Tava 1993). Distillation of the grass produces an essential oil and a hydrosol (distillate 

water) that have powerful antibiotic, antiviral, and antifungal properties which are used effectively 

against infectious and inflammatory symptoms. Several Cymbopogon species are being cultivated 

in different parts of world. Lemongrass, palmarosa, and citronella essential oils are the main raw 

material products of the cultivated cymbopogons. However, other Cymbopogon species are also 

grown in other parts of the world (Oyen and Dung 1999). 

Volatile constituents of the essential oil of C. caesius were studied by Kanjilal et al. (1995). The 

main constituents were perillyl alcohol (25.61%), geraniol (19.80%), and limonene (7.26%) along 

with 21 other compounds. Choudhury and Leclercq (1995) also studied the essential oil composition 

of C. khasianus (Munro ex Hack.) Bor from northeastern India. C. pendulus, an elemicin-rich 

aromatic grass of the Meghalaya region of India, grew well under the subtropical climatic conditions 

at Jammu, India. The essential oil obtained from this plant was rich in elemicin (53.7%), 

a starting material for developing the antibacterial drug trimethoxyprim (Shahi et al. 1997). 

Chowdhury et al. (1998) studied the essential oil of Cymbopogon species growing in Bangladesh. 

Essential oil of C. nardus (L.) Rendle growing in Zimbabwe was studied by Moody et al. (1995). 

Comparative investigation of the sesquiterpenoids present in the leaf oil of C. distans (Steud.) Wats. 

var. loharkhet and the root oil of C. jwarancusa (Jones) Schult. was performed by Beauchamp et al. 

(1996). Chisowa (1997) studied the chemical composition of flower and leaf oils of C. densiflorus 

Stapf from Zambia. 

A wide range of variation has been observed in the oil content of Cymbopogon species, and this 

is influenced by genetic, agronomic, and geoclimatic factors (Rao et al. 1980; Patra et al. 1990; 

Pandey and Chowdhury 2000). It is reported that oil content is lower during the month of heavy 

rainfall compared to the dry months (Guenther 1961). Similarly, monthly variation in the oil content 

in lemongrass over a year has been studied (Handique et al. 1984). It has also been reported 

that in some aromatic crops, the factors photoperiod, intensity of light, temperature (Voirin et al. 

1990; Lincoln and Langenhein 1978; Clark and Menary 1980), and seasons or months of harvesting 

(Rudloff and Underhill 1965; Adams 1970; Singh et al. 2000) exert a profound influence on the 

essential oil content and terpenoid composition of these crops. Diseases such as iron chlorosis significantly 

reduced biomass, essential oil yields, and total chlorophyll content of the leaves of Java 

citronella (C. winterianus), lemongrass (C. flexuosus var. flexuosus), and palmarosa (C. martinii var. 

motia) plants. 

The presence, yield, and composition of essential oils have been affected in a number of ways 

by various factors, from their formation in plants to their final isolation. Several of the factors 

of influence have been studied, particularly for commercially important crops, to optimize the 

cultivation conditions and time of harvest and to obtain higher yields of high-quality essential 

oils that fit market requirements. Knowledge of factors that determine the oil yield and chemical 

variability of aromatic plants species are thus very important. These include (1) physiological 

variations, (2) environmental conditions, (3) geographic variations, (4) genetic factors and 

evolution, (5) political/social conditions, and also (6) harvest time and technique (Figueiredo 

et al. 2008; Singh et al. 1996; Dhar et al. 1996b, 1996c; Costa et al. 2005). This chapter gives an

The Cymbopogons 109 

account of the harvesting and distillation practices that will optimize yield of quality essential 

oil from Cymbopogon species (Cassel and Vergas Rubem 2006). 

3.2 lemongrass 

Lemongrass, a perennial herb widely cultivated in the tropics, encompasses three different species: 

C. flexuosus (Steud.) Wats. (East Indian), C. citratus Stapf (West Indian), and C. pendulus (North 

Indian). The common name lemongrass has been given to these species because of the typical 

strong lemongrass-like odor of the essential oil present in the leaves. Two species, C. flexuosus and 

C. pendulus, are cultivated in India, whereas C. citratus is cultivated in the West Indies, Guatemala, 

Brazil, etc. C. citratus is a tufted perennial grass with numerous stiff leafy stems arising from 

short rhizomatous rootstocks. The aboveground parts, which contain the oil, grow to 2 m in height. 

A number of cultivars are acknowledged, which differ considerably in yield and citral content (Nair 

et al. 1979). 

Lemongrass has been used fresh, dried, or powdered. The fresh stalks are found in Asian markets 

and now in many health food markets. Lemongrass is widely used in Thai and Vietnamese cooking. 

This aromatic herb is used in Caribbean and many types of Asian cooking, and has become very 

popular in the United States. Lemongrass has been used for centuries in Indonesia and Malaysia by 

herbalists, and it is also used in Ayurvedic herbalism. It is used in teas to combat depression and bad 

moods, and to fight fever and combat nervous and digestive disorders. Studies show that lemongrass 

has antibacterial (Burt 2004; Hussain 1994) and antifungal properties (Dikshit and Hussain 1984; 

Wannissorn et al. 1996; Pandey et al. 1996; Paranagama et al. 2003; Mahanta et al. 2007). The oil 

is used to cleanse oily skin, and in aromatherapy, it is used as a relaxant. Valued for its exotic citrus 

fragrance, it is commercially used in soaps, perfumes, cosmetics, and disinfectants, and is a raw 

material for manufacturing ionones and vitamin A. 

The leaves yield aromatic oil, containing 70%–90% citral (the aldehyde responsible for the lemon 

odor). The quality of lemongrass is generally determined by its citral content (Chisowa et al. 1998). 

Citral consists of the cis-isomer geranial and the trans-isomer neral. These two are normally present 

in the ratio of about 2 to 1. C. flexuosus has higher citral content than C. citratus (Weiss 1997; 

Taskinen et al. 1983). 

Lemongrass grows wild across the tropics, and the content and quality of the oil varies among 

provenances. It prefers a warm climate with well-distributed rainfall and well-drained soil. Usually, 

it grows on poor, gravelly soils. Lemongrass is a perennial grass mainly cultivated on hill slopes as 

a rainfed crop (Pandey et al. 2001). The crop provides maximum yield from the second to fourth 

year of planting and economic yield up to the fifth year. Thereafter the yield declines considerably. 

Different cultivars of lemongrass, for example, CKP-25, OD 19, Cauvery, Pragati, and Praman, were 

evaluated for herbage and oil yield. Brief information about various cultivars is given in Table 3.1. 

Cauvery recorded the highest oil yield (Singh 1997; Rao and Lala, 1992). 

3.2.1 ha r V e s t i n G 

Harvesting time is one of the most important factors influencing optimum superior-quality oil yield. 

Depending on soil and climatic conditions, a lemongrass plantation lasts, on average, for 3–5 years 

only. The yield of biomass and oil is less during the first year, but it increases in the second year and 

reaches a maximum in the third year; after this, the yield declines. Correct harvesting procedure is 

very important. The essential oil content varies considerably during the development of the plant. If 

the plant is harvested at the wrong time, the oil yield can be severely reduced. The oil is usually contained 

in oil glands, veins, or hairs that are often very fragile. Handling will break these structures 

and release the oils. This is why a strong smell is given off when these plants are handled. Therefore,


table 3.1 

currently grown Varieties of lemongrass and their description 

Variety description 

Sugandhi (OD 19) It is adapted to a wide range of soil and climatic conditions. 

A red-stemmed variety with a plant height of 1 to 1.75 m and profuse tillering. 

The oil yield ranges from 80 to 100 kg per hectare with 85%–88% of total citral produced under 

rainfed conditions (with life-saving irrigation). 

Pragati It is a tall-growing variety with dark purple leaf sheath suitable for North Indian Plains and the Tarai 

belt of subtropical and tropical climate. 

Average oil content is 0.63% with 75%–82% citral. 

Praman It has evolved through clonal selection and belongs to the species C. pendulus. 

It is a medium-sized variety with erect leaves and profuse tillering. 

The oil yield is high with 82% citral. 

Jama rosa It is very hardy, with vigorous growth. 

The variety yields about 35 t of herbage per hectare, containing 0.4% oil (FWB). 

The variety yields up to 300 kg oil in 4–5 cuts in 16–18 months of growing period. 

RRL 16 Average herbage yield of this variety is 15–20 t/ha/annum, giving 100–110 kg oil. 

The oil content varies from 0.6% to 0.8% (fresh weight basis) with 80% citral. 

CKP 25 This is a hybrid between C. khasianum × C. pendulus. 

It gives 60 t/ha herbage in North Indian plains under irrigation. 

The oil contains 82.85% citral. 

Other varieties OD-408, Cauvery (OD-408 is a white-stemmed selection of OD-19 and is an improvement in yield in 

terms of oil and citral content. Cauvery needs high soil moisture for luxuriant growth and was 

evolved for river valley tracts.) 

these plants have to be handled very carefully to prevent valuable oils from being lost. Harvesting is 

done with the help of sickles; the plants are cut 10 cm above ground level and are allowed to wilt in 

the field before being transported to the distillation site. Seasonal influence on lemongrass has been 

reported (Handique et al. 1984; Thomas et al. 1980). 

During the first year of planting, three cuttings are obtained and, subsequently, five to six cuttings 

per year are taken, subject to weather conditions (Rana et al. 1996). The harvesting season 

begins in May and continues until the end of January. The first harvest is generally obtained after 

4–6 months of transplanting seedlings. Subsequent harvests are done at intervals of 60–70 days, 

depending on the fertility of the soil and other seasonal factors. Under normal conditions, three 

harvests are possible during the first year and three to four in subsequent years, depending on 

the management practices followed. The optimum interval between harvests to obtain maximum 

quantity of oil is 40–45 days for local types of lemongrass. For OD-19, the optimum interval was 

found to be 60–65 days when grown in hilltops and 45–55 days in valleys and lower areas (Jha et al. 

2004). Singh et al. (2000) have reported that the first harvest should be taken 90 days after planting 

to boost the development of tillerings in lemongrass. Under Jammu (India) conditions, more tillers 

with fewer harvests of lemongrass was also reported (Pal et al. 1990; Singh et al. 1978). 

Rao et al. (2005) conducted an experiment in Bengaluru (formerly Bangalore), Karnataka, India, 

during 2001–2003 to study the effect of harvest intervals on oil and citral accumulation in C. flexuosus 

cv. Krishna. The highest percentages of oil (4.8) and citral (87.1) were obtained in lemongrass 

harvested on February 17, 2002, whereas the highest percentages of geraniol (9.3) and geranyl 

acetate (2.5) were obtained with July 21, 2003, harvest. Variations in major chemical constituents 

in the oil of C. flexuosus were found in different seasons under Brahmaputra valley agroclimatic 

conditions (Sarma et al. 2003). Effect of leaf position and age on quality of oil has been discussed 

(Singh et al. 1989) whereas sucrose metabolism to components of essential oil have been studied by 

Singh and Luthra in 1988.


table 3.2 

effect of different harvesting Intervals on herb yield, oil 

content, and oil yield of lemongrass 

cutting 

Fresh herb yield (q/ha) oil content (%) oil yield (l/ha) 

75 a 100 125 75 a 100 125 75 a 100 125 

First 69.4 136.0 147.6 0.50 0.53 0.56 35.1 72.2 82.7 

Second 152.3 141.6 50.0 0.56 0.61 1.02 85.9 86.8 51.7 

Third 77.4 — — 0.77 — — 58.0 — — 

CD 5% 62.0 NS 35.4 0.16 NS 0.12 NS NS 19.2 

Note: NS = Not significant, quintal. 

a Harvesting intervals (in days). 

Source: Gill B S et al. 2007. India Perfumer 51: 23–27. 

table 3.3 

biomass yield and essential oil concentration in different Varieties 

of lemongrass at different harvests 

Varieties 

First 

harvest 

biomass yield (t/ha) essential oil concentration (%) 

second 

harvest 

third 

harvest 

total 

harvest 

First 

harvest 

second 

harvest 

third 

harvest 

OD-19 7.9 4.3 16.0 28.2 0.62 0.75 0.66 

Cauvery 6.3 3.5 25.1 34.9 0.88 1.05 1.02 

Pragati 7.7 3.4 22.5 33.6 0.71 0.80 0.70 

SHK-7 12.5 4.0 24.4 40.9 0.42 0.51 0.57 

Praman 2.2 3.8 26.6 32.6 0.63 0.71 0.61 

LSD (P = 0.05) 4.5 NS 7.2 11.9 0.18 0.04 0.14 

Note: NS = Not significant. 

Source: Rajeswara Rao B R et al. 1998. Journal of Medicinal and Aromatic Plant Sciences 20: 

407–412. 

Harvesting intervals are determined by infrastructure, management, climate, and cultivar. If 

harvested too often, the productivity of the plant will be reduced, and the plant may even die. If the 

plant is allowed to grow too large, the oil yield will be reduced. It should be 1.2 m high with four to 

five leaves. The grass should be harvested early in the morning if it is not raining. Manual harvesting 

is common, but harvesting methods adopted depend on infrastructure. The bush is cut from 

7 cm (manually) to 25 cm (mechanically) above ground. Weiss (1997) reports that each worker in 

Sri Lanka harvests 2 t of fresh grass daily. 

An experiment was conducted in Punjab, India, to determine harvest intervals in lemongrass 

(Gill et al. 2007). The results given in Table 3.2 reveal that maximum herb and oil yields were 

obtained when the cutting was taken 125 days after general harvest (in the first week of March) 

and for subsequent cuttings taken after 75-day harvesting intervals. The oil content was maximum 

75 days after general harvesting, and the oil content decreased with delay in harvesting, that is, from 

75 to 125 days in the first as well as in the second and third cuttings. The decrease in oil content 

with delay in harvesting could be attributed to the fact that as the age of the crop increases, the plant 

becomes woodier and lower leaves become dry. 

The effects of plant age (60, 67, 74, 81, 88, 95, 102, 109, and 116 days) on C. citratus biomass 

production and essential oil yield were studied in Campos dos Goytacazes, Rio de Janeiro, Brazil.


The essential oil yield decreased as plant age increased. Nevertheless, the increase in dry-matter 

production with plant age resulted in an increase in the total essential oil production (Leal et al. 

2003). Essential oil from different plant parts of lemongrass grown in Brazil was studied by Ming 

et al. (1995). The study revealed that leaf blade contains 0.42% essential oil, whereas leaf sheath has 

0.13% essential oil. 

A study was conducted in the Western Cape, which has a Mediterranean climate. The plot 

was first harvested manually when the plants were 6 months old and every month thereafter. Leaf 

growth was significantly slower in winter; therefore, a monthly cut during the colder periods was not 

possible. Studies suggest that oil yield and citral content increase in hot dry seasons (Weiss 1997). 

Frequent cutting of C. flexuosus can increase total oil yield (Weiss 1997); a similar scenario exists 

for C. citratus. 

Experiments with irrigated lemongrass (C. citratus) in Western Australia have shown that the 

highest oil yield of 419 L/ha over a 360-day period was obtained when the plants were cut at 60-day 

intervals and at a height of 20 cm. Longer intervals and higher cutting heights gave lower oil yields, 

although in some cases, fresh and dry-matter yields were increased. Studies on the effect of water 

stress showed that time between irrigations in the dry season should not be more than 10 days if oil 

yields are to be maintained. Wilting of cut lemongrass in the dry season was shown to result in a 

loss of oil, with losses increasing with the duration of wilting up to 11 h (Beech 1997). The effects of 

seasonal variation and harvest time on the foliar content of essential oil from lemongrass C. citratus 

were also studied by Beech (1990) and Leal et al. (2001). 

The effects of harvesting time (07.00, 09.00, 11.00, 13.00, 15.00, or 17.00 h) on the essential oil 

content of lemongrass (C. citratus) and on the citral and myrcene contents of the essential oil were 

studied. The highest essential oil content was obtained at 09.00 h (5.59 mL/kg dry matter) and 11.00 h 

(5.31 mL/kg dry matter). The average citral (61.23%) and myrcene (24.14%) contents suggested that 

the essential oil was probably of the West Indian type. The results indicated that lemon grass may be 

harvested between 09.00 and 11.00 h for optimum essential oil, citral, and myrcene yields. 

Outbreaks of Puccinia nakanishikii on commercial plantations of C. citratus caused reductions 

in the yield of essential oils. Healthy, uninfected leaves yielded 0.80% oil, while leaves with a 

disease index of 60%–75% yielded 0.50% oil. This reduction in essential oil yield was also accompanied 

by a decrease in the content of geraniol, and increases in the contents of neral and myrcene 

(Boruah et al. 1995). 

3.2.2 yield 

The grass yield during the first year was about 10 t/ha, which gives about 28 kg of oil. From the second 

year onward, the grass yield was about 25 t/ha, giving about 75 kg of oil. On an average, 25–30 t 

of fresh herbage are harvested per hectare per annum from four to six cuttings, which yields about 

80 kg of oil. Under irrigated conditions, from newly bred varieties, an oil yield of 100–150 kg/ha 

is obtained. The average recovery of oil is 0.30%–0.35% with 70% citral for local types of lemongrass, 

while OD-19 variety gives 0.40%–0.45% oil recovery and 85%–90% citral content. C. citratus 

yields 30–50 t/ha and continues around this level for its 4–6-year plantation life. Oil yield from 

fresh herbage is 0.25%–0.5% and even 0.4%–0.6% with good management. This data is from Weiss 

(1997), but a wide range of variation in herbage and oil yield has been reported with infrastructure 

and management playing a significant role. 

3.2.3 PostharVest Ma n a G e M e n t 

3.2.3.1 Predistillation handling 

The cut grass may be distilled fresh, but some natural reduction in the moisture content by withering 

in the sun allows greater still vessel packing and oil recoveries per batch distillation. Wilting is done


in the field where grass lies after cutting, rather than in heaps, but it should not exceed 24 h or oil 

losses may occur through brittleness and evaporation. Around 250 kg of partially wilted grass can be 

packed into 1000 L of a still vessel. The crop is chopped into small pieces before filling the stills. 

3.2.3.2 drying 

Drying techniques influence the essential oil yield and composition. The grass is allowed to wilt for 

24 h before distillation, as it reduces the moisture content by 30% and improves oil yield. In Brazil, 

a study was conducted to analyze the influence of drying on yield and composition of essential 

oil. The temperature varied from 40°C to 60°C, and the air velocities investigated were 0.2, 0.5, 

and 0.8 m/s. The highest yield was obtained at 60°C, the highest temperature investigated, and at 

0.8 m/s. At air velocities near 0.2 m/s, the lowest masses of essential oil were extracted. The differences 

between air velocities did not influence the composition of the essential oils, but did influence 

the quantity of the components in the fractions and the time of drying. The essential oil extracted 

from the wet plants present fewer components than others, and it can be explained by the fact that 

water molecules solvate the components (Peisíno et al. 2005). 

Experiments were also conducted to study the effects of drying temperature on the amount and 

quality of essential oils extracted from C. citratus (Buggle et al. 1997). Leaf blades were cut into 

small parts (about 1–1.5 cm in length) and dried for several days at 30°C, 50°C, 70°C, or 90°C, until 

a constant weight was achieved. A higher amount of oil was collected at lower drying temperatures; 

but at 30°C, leaves were affected by fungal (Aspergillus sp., Penicillium sp., Rhizopus sp., 

Cladosporium sp., Trichoderma sp., and Alternaria sp.) growth. The analysis of the oils by gas chromatography-mass 

spectrometry (GC-MS) showed variations in citral concentration (86.1%–95.2%). 

The best results were obtained at a drying temperature of 50°C (1.43% oil content). 

The effects of drying method (oven drying at 40°C or drying at room temperature using a moisture 

drier) and fragment size (powder obtained from the mill, and 1.0 cm or 20.0 cm fragments) on 

the yield and composition of the essential oil of lemongrass (C. citratus) were studied. The essential 

oil was extracted using Clevenger’s modified apparatus for 2 h. Higher essential oil and citral 

contents were obtained when the leaves were dried at room temperature. The fragment size had no 

significant effect on the evaluated parameters. 

3.2.3.3 storage 

The safe limit of herb storage varied according to the species and storage conditions. Storage of 

C. flexuosus herbage always caused a reduction in oil content except during the summer, when it 

was not affected by 3 days of storage under shade. Little variation in the geranial and neral contents 

of the essential oils of C. flexuosus leaves was observed during storage for 15 days. Temperature 

and humidity were found to play a vital role in biosynthesis accumulation of essential oils in stored 

herbs (Singh et al. 1994). 

3.2.3.4 distillation 

Distillation represents a dynamic part of a whole process in which the ethereal oils contained within 

a plant’s aromatic sac or glands are liberated through heat and pressure and transformed into a liquid 

essence of sublime beauty. The recovery of essential oils (the value-added product) from the raw 

botanical starting material is very important since the quality of the oil is greatly influenced during 

this step. There are different methods for obtaining volatile oils from plants, such as steam distillation, 

aqueous infusion, solvent extraction, cold or hot expression, and supercritical fluid extraction 

(SFE) with carbon dioxide. The chemical composition of the oil, both quantitative and qualitative, 

differs according to the technique used to obtain it from the plant parts (Sandra and Bicchi 1987). 

A comprehensive review of various techniques employed to obtain essential oil from the material 

in which it occurs was prepared by Weurman (1969). Harvesting the plant at the appropriate 

time and endeavoring to distill its essence is the art and craft of the distiller. The grass is either 

distilled afresh or is allowed to wilt for 24 h. Wilting reduces the moisture content and allows a


larger quantity of grass to be packed into the still, thereby economizing the fuel use. The current 

method of distillation adopted in different parts of India is primitive and gives oil of poor quality, 

as it is based on hydrodistillation or direct-fired still. It is being distilled in the same distilleries 

used for Japanese mint in India. Variation in the essential oil composition of rose-scented geranium 

(Pelargonium sp.) distilled by different distillation techniques, for example, water distillation, water 

steam distillation, and steam distillation, was studied by Kiran et al. (2004). For good-quality oil, it 

is advisable to adopt steam distillation. The equipment for distillation consists of a boiler to produce 

steam, a distillation tub, a condenser, and one to three separators. 

3.2.3.4.1 Steam Boiler 

A steam boiler is made of steel or galvanized sheets for steam distillation of essential oil. In developed 

countries, an oil- or gas-fired package boiler is used. Biomass-fired boilers are used in India; 

they are also quite common in remote third world countries. However, there are some distilleries that 

purchase wood, as it is a cheap local fuel, or burn fuel oil, while the spent biomass of the process is 

discarded, primarily for being too wet. 

3.2.3.4.2 Stills 

Stills come in all sizes, shapes, and materials of construction. A still is basically a tank with some 

means of injecting steam at the bottom in a way that allows its uniform distribution, such as perforated 

crosses or plates, false bottoms, manifolds, etc. This method is known as hydrodiffusion, as 

opposed to hydrodistillation. In the latter, the still is filled with the material submersed in water, and 

the oil is “boiled” out of the aromatic raw material. The opening of the still can be a simple manhole 

cover or a full-sized lid with the same diameter as the tank, depending on the unloading method. 

The steam/oil vapors exit at the upper ends of the still or through an opening in the lid, which is 

sometimes fitted with a coarse filter. 

Most stills operate at atmospheric pressure, but some are designed to withstand higher pressures, 

usually in the 2 bar range. Stills that operate under pressure are sometimes unloaded under pressure 

through a large opening at the end of a cone-shaped bottom. Materials that require frequent loading 

and unloading are processed in stills mounted on pivots that allow the still to swivel to the upsidedown 

position and dump the entire contents. The distillation tub is made of mild steel or copper 

and has a perforated bottom on which the grass rests. The tub has a steam inlet pipe at the bottom. 

A removable lid is fitted to the top. Charging and discharging can be done in perforated cages with 

iron chains, which can be lowered in the tub with the help of a chain-pulley block. 

3.2.3.4.3 Condensers 

Different types of condensers are available, but tubular condensers are better than others. The condenser 

is provided with an inlet and an outlet through which cold water is made to flow through the 

chamber to cool the pipes when the distillate flows through them. Condensers are of various types; 

they range from truck radiators to copper coils, shell and tube heat exchangers, pipes submersed in 

river-fed canals, air-cooled condensers, tube condensers inside sprinkler towers, etc., depending on 

the location, climate, available space, and resources. 

3.2.3.4.4 Oil Separators 

The oil separator is the one component that is most critical to overall product recovery and profitability 

of the plant, whether conventional or continuous. Except in modern facilities, the separator 

often seems to get the least engineering attention from distillery operators in the field. The separator, 

too, comes in a wide range of homemade designs, although the main idea is that of a continuous 

decanter, sometimes referred to as a Florentine flask. Its efficiency is governed by a number of wellknown 

variables such as oil and water specific gravity differential at various temperatures; phase 

viscosities versus ascending and descending cross-sectional velocities at various distillate flow 

rates and tank diameters; coalescing effects of different packing materials; emulsification effects;


oil solubility at various temperatures; chemical composition and polarity of the oil and its effect on 

solubility; etc. 

The stills in a typical distillery, usually two in number, are 6–9 ft high and 3–6 ft in diameter. After 

the still is tightly filled with grass, the lid is fastened on and steam let in at the bottom. The steam passes 

up through the grass, carrying off the oil through a water-cooled coil. The distillate consisting of water 

and oil is collected in steel or copper tanks about 3 ft in diameter and 18 in. deep. When the tank is 

nearly full, a siphon attachment begins to discharge the water in the lower level of the tank. The oil, 

which is lighter, floats and, when a quantity has been collected, is drawn out into bottles or drums. 

To obtain the maximum yield of oil and to facilitate its release, the grass is chopped into shorter 

lengths. Chopping the grass has further advantages in that more grass can be charged into the still 

and even packing is facilitated. It can be stored for up to 3 days under shade without any adverse 

effects on yield or quality of oil. Oil is obtained through steam distillation. The grass should be 

packed firmly as this prevents the formation of steam channels. The steam is allowed to pass into 

the still with a steam pressure of 18–32 kg in the boiler. The mixture of vapors of water and lemongrass 

oil passes into the condenser. As the distillation proceeds, the distillate collects in the 

separator. The oil, being lighter than water and insoluble, floats on the top of the separator and is 

continuously drawn off. It is then decanted and filtered. Small cultivators can use direct-fire stills, 

but in such cases, properly designed stills should be used. These stills are provided with a boiler at 

the bottom of the tub. This is separated by a false bottom from the rest of the tub. Water is poured 

at the bottom of the tub, and grass is charged in the top portion. In the still, the water does not come 

in contact with the grass. Providing a perforated disk just above the water level in the copper still 

will be helpful in producing oil of better quality. This method is known as water and steam method. 

The quality of oil suffers because of the crude method of production. To get a maximum yield of 

good-quality oil, it is advisable to use steam distillation. 

Thick stems should be removed before distillation as these are devoid of oil. Time required for 

one distillation is about 4 h, including the time required for charging and discharging, provided the 

firewood is well dried and of good quality. For one distillation, about 40 kg of firewood is required. 

A light yellow, lemon-scented volatile oil is obtained. When crop area is large enough, the steam 

method is found to be more economical. Coal can also be used as fuel. The oil has a strong lemonlike 

odor. The oil is yellowish in color, having 75%–85% citral and small amounts of other minor 

aromatic compounds. The oil content recovered from the grass ranges from 0.5%–0.8%. 

3.2.3.5 supercritical Fluid extraction (sFe) 

SFE of C. citratus yielded oil at par with steam distillation but with more compounds (Sargenti 

and Lancas 1997). A comparative analysis of the oil and supercritical CO 2 extract of C. citratus 

was done by Marongiu et al. (2006). Dried and ground lemongrass leaves were used as a matrix 

for supercritical extraction of essential oil with CO 2. The objective of this study was to analyze 

the influence of pressure on the supercritical extraction. A series of experiments were carried out 

for 360 min, at 50°C, and at different pressures: 90, 100, 110, and 120 bar. Extraction conditions 

were chosen so as to maximize the citral content in the extracted oil. The collected extracts were 

analyzed by GC-MS, and their composition was compared with that of the essential oil isolated by 

hydrodistillation and steam distillation. At higher solvent densities, the extract’s aspect changes, 

passing from a characteristic yellow-colored essential oil to a yellowish semisolid mass, because 

of the extraction of high-molecular-mass compounds. The optimum conditions for citral extraction 

were found to be 90 bar and 50°C. At these conditions, citral represents more than 68% of the 

essential oil and the extraction yield was 0.65%, while the yield obtained from hydrodistillation 

was 0.43% with a citral content of 73%. Lemongrass oil was also extracted by the SFE method. The 

essential oil yield did not increase as expected, but decreased (Rozzi et al. 2002). 

Lemongrass essential oil was extracted with dense carbon dioxide at 23°C–50°C and 85–120 bar. 

Liquid carbon dioxide extracts had a larger quantity of coextracted waxes than the supercritical 

extracts. The process condition of 120 bar and 40°C was considered ideal for the extraction of


lemon grass essential oil, as a good-quality product was obtained together with good extraction rate 

and yield (Carlson et al. 2001). 

3.2.3.6 treatment of oil Prior to storage 

Oil recovered from each distillation run is added to a settling tank, where it should be left for 

1–2 days to allow occluded water to sink to the bottom and be run off. The oil is then filtered to 

remove any solid debris and is next transferred to a bulking or storage tank. Bulking is an important 

operation since this allows for variation in oil composition between individual distillations and the 

supply to a buyer of an oil of reasonably consistent quality. Clean, new containers (steel/aluminum 

drums; UN standard) of 200 L capacity are used for shipment. Since the specific gravity of the oil is 

around 0.9, each drum will contain approximately 180 kg. For international shipment by land, sea, 

or air, drums must be labeled with appropriate identification and hazard codes. 

3.2.3.6.1 Purification of Oil 

The insoluble particles present in the oil are removed by the simple filtration method after mixing 

it with anhydrous sodium sulfate and keeping it overnight or for 4–5 h. In case the color of the oil 

changes because of rusting, then it should be cleaned by the steam rectification process. 

3.2.3.6.2 Storage and Packing of Oil 

The oil should be stored in glass bottles or containers made of stainless steel or aluminum or galvanized 

iron, depending on the quantity of oil to be stored. The oil should be filled up to the brim, 

and the containers should be kept away from direct heat and sunlight in cool or shaded places. The 

oil should be stored in well-sealed glass bottles, at 5°C–25°C, and in a dry, well-ventilated area 

away from direct heat and sunlight. Lemongrass oil can be stored for up to 3 years without affecting 

the quality of oil, if kept in aluminum containers sealed airtight using wax. Containers should be 

completely filled to exclude any air and protect the oil from sunlight as air and sunlight affect the 

citral content. 

In a study conducted at Lucknow, India, the freshly distilled, light-yellow-colored oils of palmarosa 

(C. martinii), citronella (C. nardus), and lemongrass (C. flexuosus) were stored separately 

in 1 L containers made of amber glass, plain glass, aluminum, iron, and high-density polyethylene 

(HDPE). The containers were placed in a dark room at room temperature for up to 26 months. The 

oil samples were drawn from the storage containers periodically and analyzed for the color and percentage 

composition of the major constituents of the oil. The oil changed color only when stored in 

iron containers. There was little, if any, change in the percentage composition of major constituents 

in the three oils stored in other containers (Raina et al. 1998). The following points are taken into 

consideration while storing oils: 

• Care is taken to ensure that the essential oil does not contain any water before storage. 

Amber-colored bottles are convenient for small quantities of oil. For large quantities, steel 

or aluminum drums are widely used. 

• The oils are left to stand for some time so that water can settle down. If the oil is still turbid, 

a small amount of sodium sulfate is added and the oil is filtered. The containers are 

filled up to the brim, tightly capped, and stored in a cool, dry, and dark place. 

• Exposure to air, light, and water causes deterioration of the quality of essential oil. 

3.2.4 qu a l i t y an a ly s i s 

Identification and estimation of various constituents of essential oils are carried out by gas 

chromatography.


3.2.4.1 standard specifications 

Oils Association (BEOA) in its Chemical Hazard Information and Packaging (CHIP) Regulations 

list of 1999 gives the following details: 

Hazard symbol l: Xn 

Risk phrase : R65 

H/C % : 15 

Safety phrase : S62 

In the EU, all member countries today follow the standards published by the International 

Organization for Standardization (ISO 3217-1974). The main physiochemical requirements of this 

standard for lemongrass oil are the following: 

Relative density at 20°C/20°C : 0.872–0.897 

Optical rotation at 20°C : −3º to +1º 

Refractive index at 20°C : 1.483–1.489 

Carbonyl compounds as citral mininum : 75% 

Solubility in ethanol (70% v/v) at 20°C : soluble 

In the United States, the Fragrance Manufacturers’ Association (FMA) has published a standard 

(CAS # 08007-02-1) with very similar requirements. Both the ISO and FMA standards include 

gas chromatography analysis fingerprints for West Indian type lemongrass oil, and this analytical 

technique is the first of its kind used on a sample received by a buyer. The older physicochemical 

analyzes are used when adulteration or other quality deficiencies are suspected. It is important to 

recognize that the published standard specifications are the minimum requirements of buyers and 

users. More demanding in-house quality criteria may be set by end users, and these will include 

subjectively assessed odor characteristics. 

3.3 Palmarosa (Cymbopogon martinii Var. motia (roxb.) Wats.) 

Palmarosa (Cymbopogon martinii) is a widely distributed plant in India that yields a sweet, fragrant, 

aromatic oil. In India, palmarosa oil is mostly obtained from wild-growing grass in the states 

of Madhya Pradesh, Maharashtra, Andhra Pradesh, and Karnataka. A plantation of motia variety 

was started in Punjab in 1924. The late Prof. Puran Singh, Chief Chemist, Forest Research Institute 

and Colleges, Dehra Dun, succeeded in cultivating the grass at Jaranwala (Lyallpur) over an area of 

93 ha in a short period of 4–5 years. He put up a steam distillation plant, and 1350–1600 kg of oil 

was produced annually. It was later cultivated near Dehra Dun by Purandad Essential Oil Plantation 

(Industry), and oil of good quality has been produced. Palmarosa is adapted to marginal areas and 

poor soils and can be grown under dense canopies of trees and used for soil conservation. 

Sahoo (1994) selected cultivars, namely, RRL(b)69, RRL(B)77, IW31245, IW3630, CI8041, 

and HR89 for commercial production of high-quality palmarosa oil. Recently, its cultivation has 

also been taken up in the states of Karnataka, Maharashtra, Madhya Pradesh, and Uttar Pradesh. 

Palmarosa is also flourishing on a red sandy loam soil in the semiarid tropical climate of South 

India under rainfed conditions (Rajeswara Rao 2001). The use of farmyard manure (FYM) and 

nitrogen fertilizer had a positive impact on biomass and essential oil yield. Palmarosa grass has 

also been cultivated as an intercrop with pigeon pea. The oil content and quality, in terms of total 

geraniol, of palmarosa were not adversely affected by intercropping (Maheshwari et al. 1995). The 

flowering tops and foliage contain a sweet-smelling oil that emits a rose-like odor and is widely used


in soaps, cosmetics, and perfumery industries. The oil is also used as a raw material for producing 

geraniol, which is extensively used in the perfumery industry. 

Mainly, oil of palmarosa is obtained from flowering shoots and aboveground parts of the motia 

variety of C. martinii. The variety is also referred to as rosha grass or russa grass and yields an 

oil of high geraniol content (75%–90%), which is also called East Indian geranium oil or rosha oil. 

Another variety, sofia, is also found growing wild in India, which yields an oil of lower geraniol 

content known as gingergrass oil. The oil is of inferior grade and fetches much less price than palmarosa 

oil. Oil of palmarosa is one of the most important essential oils of India that is exported, 

and once, India was the principal supplier of this oil to the world. The market for export has fallen 

because of the deterioration of the quality of oil, competition with other countries, and appearance 

of synthetic geraniol in the market. 

Essential oil composition of palmarosa grass from different places of India was studied by 

Raina et al. (2003). Geraniol (67.6%–83.6%) was the major constituent and, although the composition 

of the three oils was similar, quantitative differences in the concentrations of some constituents 

were observed. 

3.3.1 uses 

Oil of palmarosa is used in perfumery, particularly for flavoring tobacco and for the blending of 

soaps, owing to the lasting rose note it imparts to the blend. In soap perfumes, it has a special importance 

because geraniol remains stable in contact with alkali. It also serves as a source for very high 

grade geraniol. Geraniol is highly valued as a perfume and as a starting material for a large number 

of aromatic chemicals, such as geranyl esters, that have a permanent rose-like odor. 

The essential oil is distributed in all parts of the grass, such as flower heads, leaves, and stems, 

with the flower heads containing the major portion. Usually, the grass is cut at a height of 5–8 cm 

from the ground level, and the whole plant is used for distillation. The maximum yield of oil is 

obtained when the entire plant is at the full-flowering stage. The flowering tops of palmarosa consist 

of spikelets, and each spikelet is further composed of racemes and a leaf-like structure called 

a spathe. Both racemes and spathe contain essential oil. Changes in the essential oil content and 

composition during inflorescence development were studied by Dubey et al. (2000) and Dubey 

and Luthra (2001). Changes in fresh weight, dry weight, chlorophyll and essential oil content, and its 

major constituents, that is, geraniol and geranyl acetate, were examined for both racemes and spathe 

at various stages of spikelet development. The essential oil content was maximum at the unopened 

spikelets stage and decreased significantly thereafter. 

At the unopened spikelets stage, the proportion of geranyl acetate (58.6%) in the raceme oil was 

relatively greater compared to geraniol (37.2%), whereas the spathe oil contained more geraniol 

(61.9%) compared to geranyl acetate (33.4%). The relative percentage of geranyl acetate in both 

the oils, however, decreased significantly with development, and this was accompanied by a corresponding 

increase in the percentage of geraniol. Analysis of the volatile constituents from racemes, 

spathes (from mature spikelets), and seeds by capillary gas chromatography (GC) indicated 

28 minor constituents besides the major constituent geraniol. Harvesting time, stage, and duration 

of harvest play a major role in determining the herbage, quality (chemical contents), and productivity 

of the herb. 


The number of harvests depends on the climatic condition of the place of cultivation and the method 

of crop management. In the first year, usually one crop is obtained during October–November, 

whereas two to three crops are obtained in the subsequent years in subtropical areas of the North 

Indian plains. Four harvests are taken in the tropical areas of South and Northeast India. By about 

3½ to 4 months, the plants attain a height of 150–200 cm, and they start producing inflorescence.


The grass is cut 1 week after flowering. Generally, two cuttings are made during the first year of 

planting. From the second year onward, three to five cuttings are possible. It is recommended to harvest 

the crop 7–10 days after the opening of flowers. Usually, the grass is cut at a height of 5–8 cm 

from the ground level, and the whole plant is used for distillation. The maximum yield of oil is 

obtained when the entire plant is at the full-flowering stage. The harvested herbage is spread in the 

field for 4–6 h to reduce its moisture by 50%, and such semidry produce can be stacked in shady, 

cool spaces for a few days without much loss of its oil. 

Palmarosa crop should be harvested at the full-flowering stage to seeding stage to obtain a high 

oil yield of good quality. During this period, the aerial parts, that is, the stem, leaf, inflorescence, 

and the whole herb, yielded 0.05%, 0.6%, 1.0%, and 0.5% oil with 78.5% to 88.50% geraniol. It was 

observed that the essential oil, rich in geraniol, had the least geranyl acetate content (Akhila et al. 

1984). The delay or postponement of harvesting affected the yield and quality of oil. The delay led 

to an increase in leaf:stem ratio of the crop. 

An experiment conducted in Punjab, India, revealed that each delay in harvesting, from 75 

days harvesting interval to 125 days harvesting interval, increased the oil yield in the first cutting 

(Table 3.4). An oil yield of 100.6 L/ha was produced when the crop was harvested at 125 days’ harvesting 

interval as compared to 87.0 and 46.6 L/ha of 100 and 75 days’ harvesting intervals. The oil 

content in fresh herb decreased with delay in harvesting from 75 days to 125 days (Table 3.4). The 

oil content in the herb also decreased in the second cutting in all harvesting intervals as compared to 

the first cutting. Shahidullah et al. (1996) also reported that in palmarosa, essential oil content was 

highest when harvested in May compared to November. Kuriakose (1989) reported that maximum 

oil content was obtained when the crop was harvested at 90 days’ interval as compared to 50, 60, 

70, and 80 days’ interval in palmarosa. 

3.3.3 st o r a G e 

Hay storage of C. martinii (during summer) either in the shade or in the open increased the essential 

oil content. A slight difference in geraniol and geranyl acetate contents of the essential oils of 

C. martinii leaves was observed. 

3.3.4 yield 

table 3.4 

effects of different harvesting Intervals on the herbage, oil 

content, and oil yield of Palmarosa 

cutting 

Fresh herb yield (q/ha) oil content (%) oil yield (l/ha) 

75 a 100 125 75 a 100 125 75 a 100 125 

First 60.3 151.8 254.5 0.78 0.58 0.44 46.6 87.0 100.6 

Second 291.1 231.2 166.4 0.51 0.25 0.27 148.4 57.8 45.1 

Third 149.5 101.7 — 0.27 0.31 — 88.8 40.5 32.3 

CD 5% 67.8 36.1 NS NS 0.18 NS 32.1 20.8 18.9 




Palmarosa plantation remains productive for about 8 years. However, the yield of grass and oil starts 

decreasing from the fourth year onward. It is, therefore, recommended that the plantation be kept 

only for 4 to 5 years. Normally, 200–250 q/ha of fresh herbage is obtained in the first cutting, and


between 250–320 q/ha in second and subsequent harvests up to 3 years under irrigated conditions. 

On average, 200 kg of oil are received during the growing period of 15–16 months. The yield of oil 

for the first 4 years is as follows: 

3.3.5 distill ation 

First year: 60 kg/ha 

Second year: 80 kg/ha 

Third year: 80 kg/ha 

Fourth year: 80 kg/ha 

Oil of palmarosa is generally obtained by steam or hydrodistillation, similar to the process for 

lemongrass mentioned earlier. It takes 2 h to complete one distillation. The average recovery of oil 

is 0.40%–0.45%. Allowing the cut grass to wilt in the shade for 24 h during premonsoon months 

and 48 h during the postmonsoon months increases oil recovery. Small cultivators use direct-fire 

stills, but properly designed stills should be used. From the quality point of view, the grass should 

be distilled as fresh as possible. Oil obtained from dry or fermented grass is of inferior quality. For 

economic production of the oil, it is advisable that the harvested material be allowed to dry for a 

short period. The distillation unit should be clean, rust free, and free of any other odor. 

During steam distillation, a part of the essential oil becomes dissolved in the condensate or 

distillation water and is lost when this water is discarded. A method was developed to recover 

the dissolved essential oil from condensate water. The distillation water of palmarosa mixed with 

hexane in 10:1 proportion was thoroughly shaken for 30 min to trap the dissolved essential oil. 

Hexane was then distilled to yield “secondary” or “recovered” oil. In palmarosa, the “primary” or 

decanted oil (obtained directly by distilling the crop biomass) accounted for 92%, and the recovered 

oil accounted for 8% of the total oil yield. The solvent loss in this process was 4%–7%. Experiments 

conducted in the laboratory with the essential oil showed that the water solubility of palmarosa oil 

ranged from 0.12% to 0.15% at 31°C and 0.15% to 0.20% at 80°C. Hexane recovered up to 97% of 

the dissolved essential oil in water. The recovered essential oil was richer in organoleptically important 

oxygenated compounds, such as linalool (2.6%–3.8%), geraniol (91.8%–92.8%), and geranial 

(1.8%–2.0%), compared to the primary oil (Rajeswara Rao et al. 2005). 

3.3.6 oil st o r a G e 

The oil should be free of sediments, suspended matter, and moisture before storage. The container 

should be clean and rust free. 

3.3.7 oil Co n t e n t a n d yield 

The content and yield of the oil depend on many factors, such as climatic conditions of the place of 

cultivation; time of harvesting; maturity of the grass; nature of material being distilled, that is, fresh 

material or wilted material; method of distillation; etc. All parts of the plant contain the essential 

oil, the maximum oil being present in flowers and the stalks containing a negligible quantity. On 

average, the oil content in the various parts of the plant is as follows: 

Plant Parts essential oil (%) 

Whole plant 0.10–0.40 

Stalks 0.01–0.03 

Flowering tops 0.45–0.52 

Leaves 0.16–0.25


table 3.5 

Indian standard specifications for Palmarosa oil 

sl. no. characteristics requirements no. 

1. Solubility Soluble in 2 volumes of ethyl alcohol (70% by volume) 

2. Color Light yellow to yellow 

3. Odor Rosaceous with a characteristic grassy background 

4. Specific gravity 0.8740 to 0.8860 at 30°C/30°C 

5. Optical rotation −2° to +3° 

6. Refractive index 1.4690 to 1.4735 at 30°C 

7. Acid value (maximum) 3 

8. Ester value 9 to 36 

9. Ester value after acetylation 266 to 280 

10. Total alcohols, calculated as geraniol 

percent (minimum) 

90.0 

3.3.8 st a n d a r d sPeCifiCations 

Indian Standard Specifications for the oil of palmarosa (IS: 526-1986) are given in Table 3.5. 

The characteristic features of oil of palmarosa are the following: first, its sweet odor; and second, 

its solubility test in 70% alcohol (solubility of oil in 2.2–4.2 volumes of alcohol indicates 

a higher percentage of free geraniol). Oil of palmarosa chiefly contains 75.0%–95.0% alcohols, 

calculated as geraniol, and a small but varying amount of esters of the same alcohol, principally 

acetic and caproic acids. Java oils also have almost the same geraniol content, but their ester 

content is higher. 

3.4 cItronella (Cymbopogon winterianus JoWItt) 

Citronella oil is one of the industrially important essential oils obtained from different species of 

Cymbopogon. The oil is widely used in perfumery, soaps, detergents, industrial polishes, cleaning 

compounds, and other industrial products. It is classified in the trade into two types: Ceylon 

citronella oil, which is extracted from C. nardus; and Java citronella oil, which is obtained from 

C. winterianus. The major difference between these oils is the proportion of geraniol and citronellal. 

The higher proportion of geraniol and citronellal in Java-type oil makes it an important source 

of various derivatives such as citronellol and hydroxycitronellal, which are extensively used in compounding 

high-grade perfumes. The Ceylon-type citronella oil, which contains a relatively low proportion 

of geraniol and citronellal, is mainly used in cheaper products rather than for the extraction 

of derivatives (Pino and Corrla 1996). The citronella oil has export potential, and its production can 

utilize rural-sector participation (Coronel et al. 1984). 

Java citronella (Bordoloi 1982, C. winterianus) is a stoloniferous perennial that may grow up to 

1 m high. Young shoots, growing from the axillary leaves of the mother plant, develop into large 

clumps with leaves bending outward. Cultivation is normally undertaken in tropical areas up to 

an altitude of 600 m, and a well-distributed rainfall of 1500 to 2500 mm is preferable. Citronella 

adapts to a wide range of soils, but will not withstand waterlogging. Sandy soils that are fairly 

fertile are ideal. Very fertile soils provide a high biomass yield, but a low oil yield. Java citronella 

generally flourishes in areas where lemongrass is cultivated and, also, it is less susceptible to 

humidity-induced rust. Citronella showed positive correlation with irrigation and nitrogen application 

(Singh et al. 1996a). The beneficial response is obtained with moderate nitrogen application, 

while a heavy dosage enhances biomass but not oil product yields. The essential oil from C. winterianus 

of Cuban origin contains citronellal (25.04%), citronellol (15.69%), and geraniol (16.85%)


as major constituents. Brazil is classified as one of the major world producers of essential oils and 

citronella essential oil. 

The oil is used mostly in perfumery, both directly and indirectly. Soaps, soap flakes, detergents, 

household cleansers, technical products, insecticides, etc., are often perfumed exclusively 

with this oil. It is also a valuable constituent in perfumery for soaps and detergents (Hussain et al. 

1988). Citronellal is occasionally used in traces in flower compositions of citrus, cherry, ginger, 

etc. However, the greatest importance of citronellal lies in its role as a starting material for further 

derivatives. Hydroxycitronellal can be prepared from citronellal, and it is a key ingredient in compounding. 

Hydroxycitronellal is one of the most frequently used floralizing perfume materials. It 

finds its way into almost every type of floral fragrance and a great many nonfloral ones. For soap 

perfumes, a slightly rougher grade is used. High grade is used in flavor compositions. Java citronella 

is rich in geraniol (36.0%) and citronellal (42.7%) and shows repellent, antimycotic, and acaricide 

activities. It is reported to be an air freshener (Guenther 1992; Lawrence 1996). 

Cultivation of Java citronella was first introduced in the northeastern region of India by the 

Regional Research Laboratory (RRL), Jorhat, in 1965. RRL, Jammu, introduced a C. winterianus 

clone that yielded 60–70 t herbage per hectare, 0.6%–0.8% oil, and 60%–70% citronellal, which is 

extensively cultivated in the northeastern region (Sobti et al. 1982; Lal et al. 1999). 

The biosynthesis of secondary metabolites, although controlled genetically, is strongly affected 

by environmental, harvest, and postharvest factors. Agricultural factors have a critical effect on the 

quantitative and qualitative characteristics of Java citronella, which affect plant growth and yield. 

Precipitation, temperature, light, and humidity influence volatile oil yield and the main constituents’ 

content (citronellol, citronellal, and geraniol) (Sarma 2002). Sarma et al. (2001) cultivated Java 

citronella between 1998 and 2000 in Northeast India. They found a large variation in volatile oil 

yield and content, depending on seasonal changes and harvesting time. Highest yield and citronellal 

content were obtained during September and October. Under drought conditions, the geraniol 

and citronellal contents reduced, whereas citronellol content increased (Fatima et al. 2002). Saikia 

et al. (2006) studied the variation of essential oil content in leaf and inflorescence of Java citronella. 

Maximum essential oil accumulation was recorded at a crop age of 69 days during the summer 

(April–June), when the crop experienced the highest air temperature and the lowest relative humidity. 

However, the lowest air temperature and moderate relative humidity experienced by the crop 

during winter (October–January) provided good conditions for citronella oil quality (accumulation 

of citronellal, citronellol, and geraniol), which was best at a crop age of 63 days (Singh et al. 1996a). 

Java citronella cultivated at an altitude of 60 m showed elevated biomass production (24.5 t/ha) 

and volatile oil content (1.3%). An increase in citronellal content and a decrease in citronellol and 

geraniol content were observed at this altitude (Sarma et al. 2001). Misra and Srivastava (1994) 

studied the influence of iron nutrition on chlorophyll contents, photosynthesis, and essential monoterpene 

oils in Java citronella. Significant positive correlations were observed between herbage, 

total essential oil yield, and citronellol content. Yellowing and crinkling disease influenced the 

essential oil yield and composition of citronella oil from sea level. The disease decreased biomass 

yield in the first and second years of harvesting by 62.80 and 82.70, respectively. The corresponding 

decreases in essential oil yield per plant were 62.80 and 79.00 (Rajeswara et al. 2004). However, 

only few studies have been conducted on the effects of harvest time and drying throughout the different 

harvest seasons in the northeast region of Brazil (Arrigoni-Blank et al. 2005; Carvalho-Filho 

et al. 2006). 


The time of harvesting affects the yield and quality of the oil. The first harvest is generally obtained 

after 4–6 months of transplanting. Subsequent harvests take place at intervals of 50–60 days, 

depending on the fertility of the soil and seasonal factors. Under normal conditions, two to three 

harvests are possible during the first year and three to four in subsequent years, depending on the


table 3.6 

effects of different harvesting Intervals on Fresh herb 

yield, oil content, and oil yield of citronella 

cutting 

Fresh herb yield (q/ha) oil content (%) oil yield (1/ha) 

75 a 100 125 75 a 100 125 75 a 100 125 

First 26.0 29.7 33.0 1.84 1.54 0.84 46.0 44.6 28.5 

Second 63.7 89.0 90.1 1.45 1.12 1.05 92.3 99.3 94.8 

Third 50.5 10.8 — 1.19 1.18 — 61.4 12.7 — 

CD 5% 22.9 16.8 8.6 NS NS NS NS 15.5 NS 




management practices followed. Harvesting is done with the help of sickles, the plants being cut 

close to their bases about 10 cm above ground level. At harvest time, the grass is usually around 1 m 

high. The cut should be made above the first node in order to avoid the risk of dieback. Harvesting 

should be undertaken before flowering of the crop as it reduces the oil yields. Some researchers 

advocate harvesting when the stem bears six adult leaves and the seventh is rolled up. Others recommend 

cutting when the leaf tips begin to dry. The maximum yield is obtained in the third year, and 

after the fifth year the yields diminish rapidly. Mechanical harvesting is possible, but more commonly 

the grass is cut by hand. A dry day is preferable for the operation. After cutting, the grass 

should be left to wilt for a day, but care must be exercised to prevent fermentation. The oil obtained 

from this partially dry grass is more fragrant and of better quality than that obtained from grass 

distilled immediately after cutting. 

Studies were conducted at Punjab, India, to standardize the harvest intervals for citronella grass 

(Gill et al. 2007). The first cutting yielded 46.0, 44.6, and 28.5 L/ha of citronella oil at 75, 100, and 

125 days’ harvesting intervals (Table 3.6). Citronella should be harvested at 75-day interval for 

optimum yield. Shahidullah et al. (1996) reported that in citronella, essential oil content was higher 

when harvested in May compared to November. Weiss (1997) also reported that oil content of leaves 

differs significantly, and young leaves synthesize and accumulate most of the essential oil in citronella. 

Virmani et al. (1979) reported that in Java citronella, delay in harvesting causes the leaves to 

dry up, decreasing the oil yield. 

The grass is cut at all times of the year, but the yield varies with season; it is highest during the 

hot period, and low during the wet season and flowering period. The highest fresh biomass yield 

was obtained during summer (9326 kg/ha), fall (8174 kg/ha), and spring (8352 kg/ha) (Table 3.7), 

and the lowest yield during winter (3788 kg/ha). Seasons had significant effects on dry herbage biomass. 

Higher dry biomass production was achieved during fall and summer (5363 and 4897 kg/ha, 

respectively). A lower dry biomass production was obtained during winter and spring (1625 and 

3189 kg/ha, respectively); however, proportionally higher moisture was observed (61.82% and 

57.11%, respectively; Blank et al. 2007). Higher concentrations of fresh and dry biomass also were 

observed during dry seasons with irrigation. 

Another important factor influencing Java citronella volatile oil production is harvesting time. 

The results obtained are presented in Table 3.8. Most volatile oils were produced at 0900h (2.71%, 

2.22%, 2.36%, and 4.24% for summer, fall, winter, and spring seasons, respectively), because volatile 

oil content was generally found to peak at that time, except during fall, when there were no 

significant differences between harvest times. The percentage content of volatile oil in dried herbage 

was not significantly influenced by harvesting time. However, higher contents of volatile oil 

were obtained during spring (4.24%, fresh biomass; and 3.40%, dry biomass) and fall (3.17%, dry


table 3.7 

effects of seasons on Java citronella (Cymbopogon winterianus Jowitt) 

Fresh and dry biomass and moisture a 

season Fresh biomass yield (kg/ha) dry biomass yield (kg/ha) moisture content (%) 

Summer 9326 a 4897 a 34.4 

Fall 8174 a 5363 a 47.5 

Winter 3788 b 1625 c 61.8 

Spring 8352 a 3189 b 57.1 

a Biomass obtained in different seasons is not significantly different (P < 0.05). 

b About the same biomass. 

c Lowest biomass. 

Source: Blank Arie F et al. 2007. Brazilian Journal of Pharmacognosy 17(4): 557–564. 

table 3.8 

Influence of seasons and harvest times on Volatile 

oil content (In Percentage) From Fresh and dry leaves 

of C. winterianus a 

season 

oil content (%) oil yield (l/ha) 

0900 h 1200 h 1500 h 0900 h 1200 h 1500 h 

Fresh leaves 

Summer 2.71 b A 2.35 b AB 1.98 a B 162.50 a 114.82 a 97.17 a 

Fall 2.22 b A 1.84 b A 1.71 a A 119.10 a 91.47 a 98.46 a 

Winter 2.36 b A 1.98 b AB 1.67 a B 38.39 b 32.13 b 27.13 b 

Spring 4.24 a A 3.36 a B 2.43 a C 135.29 a 107.25 a 77.42 a 

dry leaves 

Summer 2.60 b A 2.47 a A 3.10 a A 127.32 b 120.79 b 151.80 a 

Fall 3.17 ab A 3.00 a A 3.20 a A 169.82 a 160.88 a 171.61 a 

Winter 2.57 b A 2.67 a A 2.33 b A 41.70 c 43.32 c 37.91 c 

Spring 3.40 a A 3.20 a A 3.50 a A 108.43 b 102.05 b 111.62 b 

a Means of oil content in same season followed by the same lowercase letter in each 

column and by the same uppercase letter in each line are not significantly different. 

Source: Blank Arie F et al. 2007. Brazilian Journal of Pharmacognosy 17(4): 557–564. 

biomass). Harvest at 1200h resulted in quite similar volatile oil content throughout all seasons. In 

general, 1500h harvest significantly reduced volatile oil content, showing the lowest value during 

winter season (2.33%, dry biomass), which is characterized by higher precipitation volumes 

(Table 3.8). In accordance with studies on C. citratus conducted by Nascimento et al. (2003), 

harvests performed at 0900h and 1100h provided higher volatile oil contents (5.59% and 5.31%, 

respectively). The chemotype citral/limonene of Lippia alba (Mill) N.E.Br. produces lower volatile 

oil content during the rainy season, which accounts for a potential metabolic decrease caused by 

reduction of solar radiation (Nagao et al. 2004). In general, winter harvest from fresh or dry leaves 

significantly reduced yield independently of harvest time (Table 3.8). 

Drying significantly increased volatile oil content and yield; this is probably due to the drying 

process affecting cell membrane resistance, assisting volatile oil release during hydrodistillation.


However, other species, such as Ocimum basilicum L., did not show significant differences between 

fresh and dry biomass (Carvalho-Filho et al. 2006), and Lippia alba showed peak volatile oil content 

at 1500h in both rainy and dry seasons. Specifically during the rainy season, volatile oil content 

increased throughout midday, decreasing by 1700h. Daily variations in temperature and luminosity 

may account for these results. The major components of C. winterianus volatile oil were identified 

as limonene, citronellal, citronellol, neral, geraniol, geranial, and farnesol. The GC-MS results 

showed that geraniol is an important volatile constituent of the volatile oil of C. winterianus, as 

well as citronellal. The content of these two compounds in fresh biomass varied with the season. 

However, no significant variation was observed for dry biomass. 

In the rainy period, the citronellal in fresh biomass reached the lowest values at 0900h and 

1200h, while the geraniol content increased. However, in the dry period (summer), the content of 

citronellal increased to 30.54% at 1500h, while the content of geraniol decreased to its lowest value 

(21.78%). Different results were observed by Rocha et al. (2002): maximum production of citronellal 

was between 0900h and 1100h. The least limonene content (1.17%) was observed in fresh leaves, 

during fall at 1200h. However, the highest limonene yield and content was achieved in plants harvested 

during winter. The content of citronellol in fresh biomass significantly decreased at 1500h 

during winter. The content of citronellol in dry biomass exhibited no significant variation. 

Drying provided an increase in citronellol during summer at 1200h, while in the rainy period 

a reduction was observed at 0900h and 1200h. In general, no significant differences in the content 

of neral were found in fresh and dry biomass throughout the harvest time and seasons, except for 

winter at 0900h when neral was absent. Higher content of neral was obtained by drying biomass 

harvested at 0900h during winter. Similarly, the content of neral increased after drying Melissa 

officinalis L. for 5 days at 40°C (Blank et al. 2007). Amounts of geranial in fresh and dry biomass 

were relatively low and not significantly different, except for dry herbage harvested at 1200h during 

the fall. Peak farnesol content was achieved only on fresh herbage during winter at 0900h, 

which decreased after drying. After drying, herbage harvested at 0900h and 1200h during summer 

showed the highest farnesol content (5.69% and 6.13%, respectively). 

According to Sarma (2002), Java citronella showed better results under high precipitation 

(100–200 mm), temperatures between 20°C and 30°C, and high moisture. In India, citronellal is 

obtained in a higher concentration during September and October, periods with favorable conditions 

locally. Chemical composition is affected in different seasons and length of drying. Time of 

harvest had little influence on composition. Java citronella showed lower volatile oil yield during 

winter. Morning harvests provide higher yield. 

Variations in citronella oil and its major constituents due to seasonal changes and stages of the 

crop were studied under the climatic conditions of Jorhat in Assam, India. Rainfall, temperature, 

sunshine, and relative humidity have a cumulative effect on oil yield and major constituents of 

the oil, namely, citronellal, citronellol, and geraniol. Postmonsoon months seemed to be favorable, 

contributing higher oil yield. Citronellal content was higher during September (44.3%) and October 

(45.7%). It was observed that light rainfall (100–200 mm), moderate temperature (20°C–30°C), 

sunshine for 5 to 6 h, and high humidity (90%–95%) were the favorable meteorological parameters 

for higher oil yields and citronellal content in citronella oil. The growing period or crop growth 

stage also had a profound effect on oil yield and citronella content. Older crops with highly matured 

leaves were found to yield higher oil and less citronellal. Alcohol content in citronella oil was not 

affected by seasonal variation. However, the total alcohol percentage was found to decrease, while 

aldehyde percentage was found to increase (Sarma 2002). 

A study was conducted in Brazil to optimize essential oil extraction processes from twigs and 

leaves by steam distillation. The process variables evaluated in this study were extraction time 

and raw material state (dry or natural). The essential oil compositions under different conditions 

were obtained with the objective of analyzing the influence of the variable value on the composition 

of citronella oil. The maximum yield, 0.942%, was obtained under the following conditions: extraction 

time—0400h and state—natural plant, and the results obtained from the factorial experimental


planning indicate that the variable that influences the essential oil yield more is the state. The principal 

compounds identified in the citronella essential oil were citronellal, citronellol, geraniol, geranyl 

acetate, and α-cadinol. 

3.4.2 st o r a G e o f C. w i n t e r i a n u s hay 

Hay storage of C. winterianus (during rainy season), either in the shade or in the open, increased 

the essential oil content of the leaves. Slight differences in the citronellal and citronellol content 

of the essential oils of C. winterianus leaves were observed. 

3.4.3 yield 

Depending on soil and climatic conditions, a citronella plantation lasts, on average, for 6 years. 

The yield of oil is less during the first year. It increases in the second year and reaches a 

maximum in the third and fourth years, after which it declines. For economy, the plantation is 

maintained only for 6 years. Up to 50 t/ha of fresh material is possible annually, but on average, 

25–30 t of fresh herbage is harvested per hectare per annum from four to five cuttings, 

which yield about 80 kg of oil. The oil content of the freshly cut material ranges from about 

0.5%–1.0%, and it is enhanced as the grass dries out through natural wilting. The annual oil 

yield under very favorable conditions can exceed 200 kg/ha, but 150 kg/ha is regarded as good 

in most situations. 

3.4.4 distill ation Pr o C e d u r e 

The same distillation units may be used for extraction of citronella essential oil as well as lemongrass 

oil. The grass is steam-distilled for better recovery of oil and for economical purposes. The 

harvested grass sometimes contains dead leaves, which should be removed. The remaining leaves 

are cut into shorter lengths. This reduces the volume of the grass, and facilities firm and even packing 

within the still. Further, chopping the grass gives a higher yield of oil than with uncut grass. 

Generally, distillation is complete within 2½ to 3 h under normal pressure starting from the initial 

condensation of the oil. About 80% of the total oil yield is recovered in the first hour, 19% in the second 

hour, and about 1% in the third hour of distillation. Larger percentages of the major components 

of the total oil, such as citronellal, geraniol, citronellol, and geranyl acetate, are recovered in the first 

hour of distillation. Steam distillation of citronella gave a maximum yield of 0.85% essential oil at 

20 psig saturated steam pressure, within 30–120 min distilling time, and at 42% moisture content. 

The moisture content in citronella has some influence on the amount of essential oil and steam utilized, 

while the quality of the oil is determined by the distilling time. 

Growers cultivating smaller areas can make use of properly designed direct-fired stills, in case 

they are not able to purchase a boiler. In such cases, the lower portion of the distillation tub is filled 

with water, and this functions as a boiler. The water in the boiler is separated from the remaining 

part of the still by means of a false perforated bottom on which the grass rests. In the still, the water 

does not come in contact with the grass. The tub is heated from below either by wood or coal, and 

the steam thus produced passes through the grass placed above in the tub, carrying oil vapors with 

it. However, distillation in such a direct-fired still takes a little more time, and the quality of the oil 

is also inferior. 

3.4.5 st a n d a r d sPeCifiCations 

In the EU, buyers use the ISO standard for Java citronella oil (ISO 3848-1976), and its main physicochemical 

requirements are summarized as follows:


Relative density at 20°C/20°C 0.880–0.895 

Refractive index 1.466–1.473 

Optical rotation −5° to 0° 

Carbonyl value Minimum 127, equivalent to 35% as citronellal 

Solubility in 80% ethanol at 20°C 1 in 2 

Ester value after acetylation Minimum 250, equivalent to 85% expressed as geraniol 

Source: Bureau of Product Standards, Department of Trade and Industry. 

In the United States, the FMA has published a standard (FMA #2308) with requirements very 

similar to those of ISO. Both the ISO and FMA standards include gas chromatography analysis fingerprints 

for Java citronella oil, and this analytical technique is the first one performed on a sample 

received by a buyer. The older physicochemical analyzes are used when adulteration or other quality 

deficiencies are suspected. It is important to recognize that the published standard specifications are 

the minimum requirements of buyers and users. More demanding in-house quality criteria may be 

set by end users, and these will include subjectively assessed odor characteristics. 

3.5 Jamrosa (Cymbopogon nardus rendle) 

Jamrosa, a hybrid between palmarosa and citronella, provides an essential oil that is used to impart 

a rosy-grassy note to natural perfumes. It is a drought-resistant hardy grass that attains a height 

of 1.5–2.5 m and has a hairy and fibrous shallow root system with long linear lanceolate leaves. It 

produces large, fawn-colored inflorescence with white, hairy, star-like spiked flowers. It is cultivated 

in the Indian states of Uttar Pradesh, Chhattisgarh, Madhya Pradesh, Rajasthan, Karnataka, 

Maharashtra, and Tamil Nadu (Shahi and Tava 1993). A well-drained sandy loam soil, free from 

waterlogging, with a soil pH of 7.5–8.5 is ideal for cultivation. A warm tropical climate and up 

to 300 m elevations in the foothills are suitable for cultivation of jamrosa. Temperatures ranging 

from 10°C–36°C with annual rainfall around 1000–1500 mm and ample sunshine are congenial for 

its growth. A moist and warm climate throughout the year accelerates its growth. Areas that are 

affected by severe frost are not suitable, as the frost kills the grass and reduces the oil content. 

3.5.1 uses 

Oil of jamrosa is used in perfumery, particularly for flavoring tobacco and for blending soaps, 

because of the lasting rose note it imparts to the blend. It also serves as a source of very high-grade 

geraniol. Geraniol is highly valued as a perfume and as a starting material for large chemicals, such 

as geranyl esters, that have a permanent rose-like odor. 


The essential oil is distributed in all parts of the grass, that is, flower heads, leaves, and stems, with 

the flower heads having the major content. It is recommended to harvest the crop 7–10 days after 

the opening of flowers. The number of harvests depends on the climatic condition of the place of 

cultivation and method of crop management. During the first year, usually one crop is obtained 

during October–November, whereas two to three crops are obtained in the subsequent years in the 

subtropical areas of the North Indian Plains. Four harvests are taken in the tropical areas of South 

and Northeast India. Usually, the grass is cut at a height of 5–8 cm from the ground level, and the 

whole plant is used for distillation. The maximum yield of oil is obtained when the entire plant is at 

the full-flowering stage. The harvested herbage is spread in the field for 4–6 h to reduce its moisture


by 50%, and this semidry produce can be stacked in shady, cool spaces for a few days without much 

loss of its oil. 

The effect of seasonal changes on oil content of a new clone of jamrosa, RL-931 (C. nardus var. 

confertiflorus × C. jwarancusa), was investigated by Bhan et al. (2003). The time of harvesting was 

found to be very crucial for the productivity of oil per unit area. Biosynthesis of oil coupled with its 

main constituents is directly associated with the timing of harvest. RL-931 showed a good deal of 

variation in oil content from the first harvest to the fourth harvest of the season. The premonsoon 

and onset of the monsoon period (May–July) was characterized by higher oil content (1.0%), whereas 

the postmonsoon and winter period (August–December) showed comparatively lower oil content 

(0.7%). These findings were in accordance with the results obtained for lemongrass (Handique et al. 

1984b). The quality of the oil is best in May–July. High temperature and low humidity favor the 

accumulation of geraniol, geranyl acetate, and a low citral content in the oil. Maximum oil content 

was recorded when both maximum and minimum temperatures were high. 

Central India is more suitable for growing aromatic grasses because of the large area under 

degraded forest lands. Many commercial houses in Chhattisgarh have entered into agreements 

to buy back aromatic plant produce, and the state government has announced Chhattisgarh as an 

herbal state because it has the climatic conditions most suited to aromatic plant production. To promote 

aromatic plant production, the chief emphasis is to be given to the establishment of processing 

units for oil extraction. Leaf collection will generate about 1 million man-days, and this will provide 

enormous employment opportunities. Patchouli and jamrosa keep yielding for 2 years with minimal 

expenditure in the second year, which will further enhance the income of farmers. 

3.5.3 distill ation 

Jamrosa grass oil can be obtained by the method mentioned previously for lemongrass. 

3.5.4 yield 

Jamrosa plantations remain productive for about 8 years. However, the yield of grass and oil starts 

decreasing from the fourth year onward. It is, therefore, recommended that the plantation be kept 

only for 4 years. Normally, 200–250 q/ha of fresh herbage is obtained in the first cutting and between 

250 and 320 q/ha in the second and subsequent harvests for up to 3 years under irrigated conditions. 

On average, 200 kg of oil is received during the growing period of 15–16 months. 

The yield of oil (in kg/ha) for the first 4 years is as follows: 

3.6 conclusIon 

First year 60 

Second year 80 

Third year 80 

Fourth year 80 

India is considered to be one of the leading producers of essential oils. However, the oil distilled 

by traditional raw methods does not fetch a good value in the international market. Improvements 

in extraction technology and the use of oil as a raw material can change this scene. To increase 

India’s participation in the international market, it is necessary to improve extraction technology in 

order to obtain products having international quality standards. Research on improving distillation 

technology is required to increase oil quality and distillation efficiency. Intermediate solutions to 

save energy using existing equipment, such as methods to insulate the stainless steel drums, should 

be explored.


reFerences 

Adams R P. 1970. Seasonal variation of terpenoid constituents in natural population of Juniperus pinchotii 

Sudw. Phytochemistry 9: 397–402. 

Akhila A, Tyagi B R, Naqvi A. 1984. Variation of essential oil constituents in Cymbopogon martinii Wats. var. 

motia at different stages of plant growth. Indian Perfumer 28: 126–128. 

Anonymous. Handbook of Medicinal and Aromatic Plants, Citronella (Cymbopogon winterianus Jowitt). 

NEDFI, pp. 13–18. 

Arrigoni-Blank M F, Silva-Mann R, Campos D A, Silva P A, Antoniolli A R, Caetano L C, Sant’Ana A E G, 

Blank A F. 2005. Morphological, agronomical and pharmacological characterization of Hyptis pectinata 

(L.) Poit germplasm. Revista Brasileira Farmacognosia 15: 298–303. 

Beauchamp P S, Dev V, Docter D R, Ehsani R, Vita G, Melkani A B, Mathela C S, Bottini A T. 1996. 

Comparative investigation of the sesquiterpenoids present in the leaf oil of Cymbopogon distans (Steud.) 

Wats. var. loharkhet and the root oil of Cymbopogon jwarancusa (Jones) Schult. Journal of Essential Oil 

Research 8(2): 117–121. 

Beech D F. 1997. Growth and oil production of lemongrass (Cymbopogon citratus) in the Ord Irrigation Area, 

Western Australia. Australian Journal of Experimental Agriculture and Animal Husbandry 17(85): 

301–307. 

Beech D F. 1990. The effect of carrier and rate of nitrogen application on the growth and oil production of 

lemongrass (Cymbopogon citratus) in the Ord Irrigation Area, Western Australia. Australian Journal of 

Experimental Agriculture 30(2): 243–250. 

Bhan M K, Rekha Kanti, Kak S N, Agarwal S G, Dhar P L, Thappa R K. 2003. Variation of oil content in a new 

clone of Jamrosa ‘RL-931’ (Cymbopogon nardus var. confertiflorus × C. jwarancusa) during one year of 

crop growth. New Zealand Journal of Crop and Horticultural Science 31: 187–191. 

Blank Arie F, Costa Andressa G, Arrigoni-Blank Maria de Fátima, Cavalcanti Sócrates C H, Alves Péricles B, 

Innecco Renato, Ehlert Polyana A D, de Sousa Inajá Francisco. 2007. Influence of season, harvest 

time and drying on Java citronella (Cymbopogon winterianus Jowitt) volatile oil. Brazilian Journal of 

Pharmacognosy 17(4): 557–564. 

Bordoloi D N. 1982. Citronella oil industry in North East India. In Cultivation and Utilization of Aromatic 

Plants, Regional Research Laboratory, Jammu, Tawi, India, pp. 318–324. 

Boruah P, Misra B P, Pathak M G, Ghosh A C. 1995. Dynamics of essential oil of Cymbopogon citratus (DC) 

Stapf. under rust disease indices. Journal of Essential Oil Research 7(3): 337, 338. 

Buggle V, Ming L C, Furtado E L, Rocha S F R, Marques M O M. 1997. Influence of different drying 

temperatures on the amount of essential oils and citral content in Cymbopogon citratus (DC) 

Stapf., Proceedings of the Second World Congress on Medicinal and Aromatic Plants, WOCMAP-2. 

Biological resources, sustainable use, conservation and ethnobotany, Mendoza, Argentina, November 

10–15, 1997 [edited by Caffini N, Bernath J, Craker L, Jatisatienr A, Giberti G]. Acta Horticulturae, 

1999, No. 571–574. 

Carlson Luiz H C, Machado R A F, Spricigo C B, Pereira L K, Bolzan A. 2001. Extraction of lemongrass essential 

oil with dense carbon dioxide. Journal of Supercritical Fluids 21(1): 33–39. 

Carvalho-Filho J L S, Blank A F, Alves P B, Ehlert P A D, Melo A S, Cavalcanti S C H, Arrigoni-Blank M F, 

Silva-Mann R. 2006. Influence of the harvesting time, temperature and drying period on basil (Ocimum 

basilicum L.) essential oil. Revista Brasileira Farmacognosia 16: 24–30. 

Cassel E, Vergas Rubem M F. 2006. Experiments and modelling of the Cymbopogon winterianus essential oil 

extraction by steam distillation. Journal of the Mexican Chemical Society 50(3): 126–129. 

Chisowa, E H. 1997. Chemical composition of flower and leaf oils of Cymbopogon densiflorus Stapf. from 

Zambia. Journal of Essential Oil Research 9(4): 469, 470. 

Chisowa E H, Hall D R, Farman D I. 1998. Flavour and Fragrance Journal 13: 29, 30. 

Chowdhury J U, Mohammed Yusuf, Jaripa Begum, Mondello L, Previti P, Dugo G. 1998. Studies on the essential 

oil bearing plants of Bangladesh. Part IV. Composition of the leaf oils of three Cymbopogon species: 

C. flexuosus (Nees ex Steud.) Wats., C. nardus (L.) Rendle var. confertiflorus (Steud.) N. L. Bor and 

C. martinii (Roxb.) Wats. var. martinii. Journal of Essential Oil Research 10(3): 301–306. 

Choudhury S N, Leclercq P A. 1995. Essential oil of Cymbopogon khasianus (Munro ex Hack.) Bor from 

northeastern India. Journal of Essential Oil Research 7(5): 555, 556. 

Clark R J, Menary R C. 1980. Environmental effects on peppermint (Mentha piperita L.). I. Effect of day 

length, photon flux density, night temperature and day temperature on the yield and composition of peppermint 

oil. Australian Journal of Plant Physiology 7: 685–692.


Coronel V Q, Anzaldo F E, Recaña M P. 1984. Effect of moisture content on the essential oil yield of lemongrass 

and citronella. NSTA Technology Journal, Vol. IX No. 3. 

Costa L C do B, Correa R M, Cardoso J C W, Pinto J E B P, Bertolucci S K V, Ferri P H. 2005. Yield and composition 

of essential oil of lemongrass under different drying and fragmentation conditions. Horticultura 

Brasileira 23(4): 956–959. 

Dhar A K, Dhar R S, Rekha K, Koul S. 1996. Effect of spacings and nitrogen levels on herb and oil yield, oil 

concentration and composition in three selections of Cymbopogon jwarancusa (Jones) Schultz. Journal 

of Spices and Aromatic Crops 5(2): 120–126. 

Dikshit A, Husain A. 1984. Antifungal action of some essential oils against animal pathogens, Fitoterapia 

55(3): 171–176. 

Dubey V S, Mallavarapu G R, Luthra R. 2000. Changes in the essential oil content and its composition during 

palmarosa (Cymbopogon martinii (Roxb.) Wats. var. motia) inflorescence development. Flavour and 

Fragrance Journal 15(5): 309–314. 

Dubey V S, Luthra R. 2001. Biotransformation of geranyl acetate to geraniol during palmarosa (Cymbopogon 

martinii, Roxb. Wats. var. motia) inflorescence development, Phytochemistry 57(5): 675–680. 

Dutta S C. 1982. Cultivation of Cymbopogon winterianus Jowitt for production of citronella (Java) oil. In Cultivation 

and Utilization of Aromatic Plants, Regional Research Laboratory, Jammu, Tawi, India, pp. 325–329. 

Fatima S, Farooqi A H A, Sharma S. 2002. Physiological and metabolic responses of different genotypes of 

Cymbopogon martinii and C. winterianus to water stress. Plant Growth Regulation 37: 143–149. 

Figueiredo A C, Barroso J G, Pedro L G, Scheffer J J C. 2008. Factors affecting secondary metabolite production 

in plants: volatile components and essential oils. Flavour and Fragrance Journal 23(4): 213–226. 

Gill B S, Salaria A, Kaur Satvinder, Gill G S. 2007. Harvesting management studies in lemongrass, palmarosa 

and citronella, India Perfumer 51: 23–27. 

Guenther E. 1950. Oils of citronella, essential of citronella, aceite essential citronella, citronellol, oleum citronellac. 

In The Essential Oils, Vol. IV. pp. 65–82. Van Nostrand, London. 

Guenther E. 1961. The Essential Oils, Vol. IV. D. Van Nostrand, New York. 

Guenther E. 1992. The Essential Oils. D. Van Nostrand, Princeton, New Jersey. 

Handique A K, Gupta R K, Bordoloi D N. 1984a. Variation of oil content in lemongrass and its genetic aspects. 


Handique A K, Gupta R K, Bordoloi D N. 1984b. Variation of oil content in lemongrass as influenced by seasonal 

changes and its genetic aspects. Indian Perfumer 28: 54–63. 

Hussain A, Virmoni O P, Sharma A, Mishra L N. 1988. Citronella oil (Java) Cymbopogon winterianus Jowitt. 

In Major Essential Oil Bearing Plants of India, pp. 52–57. 

Hussain A. 1994. Essential Oil Plants and Their Cultivation. Central Institute of Medicinal and Aromatic Plants, 

Lucknow, India. 

Jha B K, Kumar D, Joshi P P. 2004. Harvesting frequency in lemongrass var. OD-19 under semi-arid ecosystem 

of Gujarat. Indian Perfumer 48(3): 317–321. 

Kanjilal P B, Pathak M G, Singh R S, Ghosh A C. 1995. Volatile constituents of the essential oil of Cymbopogon 

caesius (Nees ex Hook. et Arn.) Stapf. Journal of Essential Oil Research 7(4): 437–439. 

Kiran G, Babu, D, Kaul V K. 2004. Variation in essential oil composition of rose-scented geranium (Pelargonium 

sp.) distilled by different distillation techniques. Flavour and Fragrance Journal 20(2): 222–231. 

Kuriakose K P. 1989. Stage of harvest trial in palmarosa. Indian Perfumer 33(1): 21, 22. 

Lal R K, Sharma J R, Misra H O. 1999. Development of new variety Manjari of citronella Java (Cymbopogon 

winterianus). Journal of Medicinal and Aromatic Plant Sciences 21(3): 727–729. 

Lawrence B M. 1996. Progress in essential oils. Perfumer and Flavorist 21(1): 37–45. 

Leal T C A B, Freitas S P, Silva J F, Carvalho A J C. 2001. Evaluation of the effect of season variation and 

harvest time on the foliar content of essential oil from lemongrass (Cymbopogon citratus (DC) Stapf.). 

Crop Husbandry 48(278): 445–453. 

Leal T C A B, Freitas S P, Silva J F, Carvalho A J C. 2003. Production of biomass and essential oil in plants of 

lemongrass (Cymbopogon citratus (DC) Stapf) of various ages. Revista Brasileira de Plantas Medicinais 

5(2): 61–64. 

Lincoln D E, Langenheim J H. 1978. Effect of light and temperature on monoterpenoid yield and composition 

in Satureja douglasii. Biochemical Systematics and Ecology 24: 627–635. 

Mahanta J J, Chutia M, Bordoloi M, Pathak M G, Adhikary R K, Sarma T C. 2007. Cymbopogon citratus L. 

essential oil as a potential antifungal agent against key weed moulds of Pleurotus spp. spawns. Flavour 

and Fragrance Journal 22(6): 525–530.


Maheshwari S K, Sharma R K, Gangrade S K. 1995. Effect of spatial arrangement on performance of palmarosa 

(Cymbopogon martini var. motia)-pigeonpea (Cajanus cajan) intercropping on a black cotton soil 

(vertisol). Indian Journal of Agronomy 40(2): 181–185. 

Marongiu B, Piras A, Porcedda S, Tuveri E. 2006. Comparative analysis of the oil and supercritical CO(2) 

extract of Cymbopogon citratus Stapf. Natural Product Research 20(5): 455–459. 

Ming L C, Figueiredo R O, Machado S R, Andrade R M C. 1995. Yield of essential oil of and citral content in 

different parts of lemongrass leaves (Cymbopogon citratus (D.C.) Stapf.) Poaceae. International symposium 

on medicinal and aromatic plants, Amherst, Massachusetts, August 27–30, 1995 [edited by Craker 

L E, Nolan L, Shetty K] Acta Horticulturae (1996) (No. 426): 555–559. 

Misra A, Srivastava N K. 1994. Influence of iron nutrition on chlorophyll contents, photosynthesis and essential 

monoterpene oil(s) in Java citronella (Cymbopogon winterianus Jowitt). Photosynthetica 30(3): 

425–434. 

Moody J O, Adeleye S A, Gundidza M G, Wyllie G, Ajayi-Obe O O. 1995. Analysis of the essential oil of 

Cymbopogon nardus (L.) Rendle growing in Zimbabwe. Pharmazie 50(1): 74, 75. 

Nagao E O, Innecco R, Mattos S H, Filho S M, Marco C A. 2004. Effect of the harvest time on content and 

major constituent of essential oil of Lippia alba (Mill) N.E.Br., chemotype citral-limonene. Cienc Agron 

35: 355–360. 

Nair E C G, Chinnamma N P, Puspha Kumari R. 1979. A quarter century of research on lemongrass at lemongrass 

research station. Indian Perfumer 23(3): 218, 219. 

Nascimento I B do, Innecco R, Marco C A, Mattos S H, Nagao E O. 2003. Effects of cutting time on the essential 

oil of lemon grass. Revista Ciencia Agronomica 34(2): 169–172. 

Oyen L P A, Dung N X. 1999. Plant Resources of South-East Asia No. 19: Essential Oil Plants. Backhuys 

Publishers, Leiden. 

Pal S, Chandra S, Singh S, Balyan S, Kaul B L. 1990. Harvest management studies on lemongrass (CKP–25)—a 

new hybrid strain. Indian Perfumer 34(3): 213–216. 

Panda H. 2005. Cultivation and Utilization of Aromatic Plants. Asia Pacific Business Press Delhi, 600 pp. 

Pandey A K, Chowdhury A R. 2000. Chemical composition of essential oil of Cymbopogon flexuosus from 

Central India. Proceedings of Centennial conference on Spices and Aromatic Plants, September 20–23, 

2000, Calicut, Kerala, India. 

Pandey A K, Pandey B K, Banerjee S K, Shukla P K. 2001. Oushdhiya Paudhon Ki Kheti-Lemongrass 

(Cymbopogon flexuosus), 73 ICFRE-BR-15,CFRHRD-BR-4, Chhindwara, Madhya Pradesh, India. 

Pandey M C, Sharma J R, Dikshit A. 1996. Antifungal evaluation of the essential oil of Cymbopogon pendulus 

(Nees ex Steud.) Wats. cv. Praman. Flavour and Fragrance Journal 11(4): 257–260. 

Paranagama P A, Abeysekera K H T, Abeywickrama K, Nugaliyadde L. 2003. Fungicidal and anti-aflatoxigenic 

effects of the essential oil of Cymbopogon citratus (DC.) Stapf. (lemongrass) against Aspergillus flavus 

Link. isolated from stored rice. Letters in Applied Microbiology 37(1): 86–90. 

Patra D D, Singh R, Singh D V. 1990. Agronomy of Cymbopogon species. Current Research on Medicinal and 

Aromatic Plants 12: 72–84. 

Peisíno Alan Luppi, Alberto Diogo Laranja, Mendes Marisa, Calçada Luís Américo. 2005. Study of the frying 

effects in the composition of the essential oil of Lemon grass (Cymbopogan citratus). 2nd Mercosur 

Congress on Chemical Engineering, ENPROMER 2005. Rio de Janeiro, Brazil. 

Pino J A, Rosado A, Correa M T. 1996. Chemical composition of the essential oil of Cymbopogon winterianus 

Jowitt from Cuba. Journal of Essential Oil Research 8(6): 693, 694. 

Rana V, Prakash Om, Joshi C S. 1996. Effect of nitrogen application and cutting frequencies on productivity of 

lemongrass (Cymbopogon flexuosus) under Poplar (Populus deltoids) plantation. Indian Perfumer 40(3): 

67–72. 

Raina V K, Srivastava S K, Tandon S, Mandal S, Aggarwal K K, Kahol A P, Sushil Kumar. 1998. Effect of 

container materials and long storage periods on the quality of aromatic grass oils. Journal of Medicinal 

and Aromatic Plant Sciences 20(4): 1013–1017. 

Raina V K, Srivastava S K, Aggarwal K K, Syamasundar K V, Khanuja S P S. 2003. Essential oil composition of 

Cymbopogon martinii from different places in India. Flavour and Fragrance Journal 18(4): 312–315. 

Rajeswara Rao B R, Chand S, Bhattacharya A K, Kaul P N, Singh C P, Singh K. 1998. Response to lemongrass 

(Cymbopogon flexuosus) cultivars to spacing and NPK fertilizers under irrigated conditions in semi-arid 

tropics. Journal of Medicinal and Aromatic Plant Sciences 20: 407–412. 

Rajeswara Rao B. R. 2001. Biomass and essential oil yields of rainfed palmarosa (Cymbopogon martinii (Roxb.) 

Wats. var. motia Burk.) supplied with different levels of organic manure and fertilizer nitrogen in semiarid 

tropical climate. Industrial Crops and Products 14(3): 171–178.


Rajeswara Rao B R, Bhattacharya A K, Mallavarapu G R, Ramesh S. 2004. Yellowing and crinkling disease 

and its impact on the yield and composition of the essential oil of citronella (Cymbopogon winterianus 

Jowitt). Flavour and Fragrance Journal, 19(4): 344–350. 

Rajeswara Rao B R, Kaul P N, Syamasundar K V, Ramesh S. 2005. Chemical profiles of primary and secondary 

essential oils of palmarosa (Cymbopogon martinii (Roxb.) Wats var. motia Burk.). Industrial Crops and 

Products 21(1): 121–127. 

Rao B L, Verma V, Sobti S N. 1980. Genetic variability in citral containing Cymbopogon khasianus. Indian 


Rao B L, Lala S. 1992. Optimization of oil yield in CKP-25. Indian Perfumer 36(4): 246, 247. 

Rao E V S P, Rao R S G, Puttanna K, Ramesh S. 2005. Significance of harvest intervals on oil content and 

citral accumulation in variety Krishna of lemongrass (Cymbopogon flexuosus). Journal of Medicinal and 

Aromatic Plant Sciences 27(1): 1–3. 

Rao P G. 2006. Citronella. Regional Research Laboratory, Jorhat, India. 

Reverchon E. 1997. Supercritical fluids extraction and fractionation of essential oils and related products. 

Journal of Supercritical Fluids 10: 1–37. 

Rocha M F A, Borges N S S, Inneco R, Mattos S H, Nagao E O. 2002. Influencia do Larario de Corte Sobre o 

Citronellol do oleo essencial (Cymbopogon winterisnus). Hortio Bras 20(Suppl.): 1–4. 

Rozzi N L, Phippen W, Simon J E, Singh R K. 2002. Supercritical fluid extraction of essential oil components 

from lemon-scented botanicals. Lebensmittel-Wissenschaft und–Technologie, 35(4): 319–324. 

Rudloff V E, Underhill W E. 1965. Seasonal variation in the volatile oil from Tanacetum vulgare L. 


Sahoo S. 1994. Variability, selection and mutation for palmarosa oil production in India. Journal of Herbs, 

Spices & Medicinal Plants 2(3): 49–57. 

Saikia R C, Sarma A, Sarma T C, Baruah P K. 2006. Comparative study of essential oils from leaf and inflorescence 

of Java citronella (Cymbopogon winterianus Jowitt). Journal of Essential Oil Bearing Plants 9(1): 85–87. 

Sandra P, Bicchi C. 1987. Capillary Gas Chromatography in Essential Oil, Heidelberg, Basel, New York. 

Sargenti S R, Lancas F M. 1997. Supercritical fluid extraction of Cymbopogon citratus (DC.) Stapf. Chromatographia 

465: 6285. 

Sarma A, Sarma T C, Handique A, Baruah A K S. 2003. Variation in major chemical constituents in the oil of 

lemon grass (Cymbopogon flexuous [Stud. Wats]), association in different seasons under Brahmaputra 

valley agro-climatic conditions, FAFAI Journal 5(2): 43–49. 

Sarma T C, Sharma R K, Adhikari R K, Saha B N. 2001. Effect of altitude and age on herb yield, oil and its 

major constituents of Java citronella (Cymbopogon winterianus Jowitt.). Journal of Essential Oil Bear ing 

Plants 4: 77–81. 

Sarma T C. 2002. Variation in oil and its major constituents due to season and stage of the crop in Java citronella 

(Cymbopogon winterianus Jowitt). Journal of Spices and Aromatic Crops 11(2): 97–100. 

Shahi A K, Tava A. 1993. Essential oil composition of three Cymbopogon species of Indian Thar Desert. 

Journal of Essential Oil Research 5: 639–643. 

Shahi A K, Sharma S N, Tava A. 1997. Composition of Cymbopogon pendulus (Nees ex Steud) Wats, an 

elemicin-rich oil grass grown in Jammu region of India. Journal of Essential Oil Research 9(5): 

561–563. 

Shahidullah M, Huq M F, Islam U, Karim M A, Begum F. 1996. Effect of number of harvests on herbage yield 

and oil content of citronella and palmarosa grasses. Bangladesh Journal of Scientific and Industrial 

Research 31(1): 127–135. 

Singh A, Balyan S S, Shahi A K. 1978. Harvest management studies and yield potentiality of Jammu lemongrass. 

Indian Perfumer 22(3): 189–191. 

Singh A K, Naqvi A A, Ram G, Singh K. 1994. Effect of hay storage on oil yield and quality in three Cymbopogon 

species (C. winterianus, C. martinii and C. flexuosus) during different harvesting seasons. Journal of 

Essential Oil Research 6(3): 289–294. 

Singh A K, Ram G, Sharma S. 1996. Accumulation pattern of important monoterpenes in the essential oil of 

citronella Java (Cymbopogon winterianus) during one year of crop growth. Journal of Medicinal and 


Singh K, Kothari S K, Singh D V, Singh V P, Singh P P. 2000. Agronomic studies in cymbopogons—a review. 

Journal of Spices and Aromatic Crops 9(1): 13–22. 

Singh M, Chandrasekhara G D, Rao E V S P. 1996b. Oil and herb yields of Java citronella (Cymbopogon winterianus 

Jowitt) in relation to nitrogen and irrigation regimes. Journal of Essential Oil Research 8(5): 

531–534.


Singh M. 1997. Growth, herbage, oil yield, nitrogen uptake and nitrogen utilization efficiency of different 

cultivars of lemongrass (Cymbopogon flexuosus) as affected by water regimes. Journal of Medicinal and 


Singh M, Shivaraj B, Sridhara S. 1996c. Effect of plant spacing and nitrogen levels on growth, herb and oil 

yields of lemongrass (Cymbopogon flexuosus (Steud.) Wats. var. Cauvery). Journal of Agronomy and 

Crop Science 177(2): 101–105. 

Singh M. 2001. Long-term studies on yield, quality and soil fertility of lemongrass (Cymbopogon flexuosus) in 

relation to nitrogen application. Journal of Horticultural Science and Biotechnology 76(2): 180–182. 

Singh N, Luthra R, Sangwan R S. 1989. Effect of leaf position and age on the essential oil quantity and quality 

in lemongrass (Cymbopogon flexuosus) Planta Medica 55(3): 254–256. 

Singh N, Luthra R. 1988. Sucrose metabolism and essential oil accumulation during lemongrass (Cymbopogon 

flexuosus Stapf.) leaf development. Plant Science 57: 127–133. 

Sobti S N, Verma V, Rao B L. 1982. Scope for development of new cultivars of Cymbopogon as a source of 

terpene chemicals. In Cultivation and Utilization of Aromatic Plants, Regional Research Laboratory, 

Jammu, Tawi, India, pp. 302–307. 

Sushil K, Samresh D, Kukreja A K, Sharma J R, Bagchi G D. 2000. Cymbopogon: The Aromatic Grass 

Monograph. Central Institute of Medicinal and Aromatic Plants, Lucknow, India, 380 pp. 

Taskinen J, Mathela D K, Mathela C S. 1983. Composition of the essential oil of Cymbopogon flexuosus. 

Journal of Chromatography A 262: 364–366. 

Thomas J, Geetha K, Joy P P. 1980. Comparative performance of lemon grass species. Indian Perfumer 34: 

171, 172. 

Virmani O P, Singh K K, Singh P. 1979. Java Citronella and its Cultivation in India. Central Institute of 

Medicinal and Aromatic Plants, Farm Bulletin No. 1, Lucknow, India. 

Voirin B, Brun N, Bayet C. 1990. Effect of day length on the monoterpene composition of leaves of Mentha 

piperita. Phytochemistry 29: 749–755. 

Wannissorn B, Jarikasem S, Soontorntanasart T. 1996. Antifungal activity of lemon grass oil and lemon grass 

oil cream. Phytotherapy Research 10(7): 551–554. 

Weurman C. 1969. Journal of Agricultural and Food Chemistry 17: 370. 

Weiss E A. 1997. Gramineae. In Essential Oil Crops. CAB International, Wallingford, U.K., pp. 59–137.

4 

contents 

Biotechnological Studies 

in Cymbopogons 

Current Status and Future Options 


4.1 Introduction .......................................................................................................................... 135 

4.2 Cymbopogon: The Aromatic Genus ..................................................................................... 136 

4.3 Biotechnological Studies in Cymbopogons .......................................................................... 137 

4.3.1 Tissue Culture Studies .............................................................................................. 137 

4.3.2 Phylogenetic Studies ................................................................................................. 139 

4.3.3 Metabolic Engineering Studies................................................................................. 141 

4.4 Future Options in Biotechnology of Cymbopogons ............................................................. 142 

4.5 Conclusion ............................................................................................................................ 144 

References ...................................................................................................................................... 145 


Human dependence on plants for food, shelter, flavors, fragrance, colors, and health is prehistoric. 

Recent years have witnessed an unprecedented preference for natural herbals in health, nutraceuticals, 

and cosmetic sectors, and the gap between demand and supply is fast widening. Since the 

majority of medicinal and aromatic plants are still collected from the wild, several natural populations 

are being threatened or extinction. This changing scenario demands two immediate measures: 

(1) bringing more and more medicinal and aromatic plants under organized cultivation/domestication 

and (2) upgrading conventional plant improvement techniques with modern tools of plant 

biotechnology (Galili 2002; Gomez-Galera et al. 2007; Kole 2007). The human quest to improve 

the yield and quality of bioresources dates back to more than 10,000 years, with simple selection 

of traits quantifiable at the naked-eye level (Jauhar 2006). Such empirical selective breeding 

approaches then moved toward channelization of useful genes through conscious hybridization to 

induction of novel characters through deliberate mutation and polyploid breeding. With the advent 

of cell and tissue culture approaches coupled with tools of genetic engineering, the state of the art 

has reached to a level where crops are being designed by borrowing genes of interest from across 

the taxonomic boundaries, spread over plant, animal and microbial kingdoms (Vasil 2005; Datta 

2007; Jullien 2007). Flava-savor tomato, golden rice and Bt-cotton are just a few examples of the 

tremendous advantages that these tools of plant biotechnology can offer if properly amalgamated 

with traditional breeding approaches. 

Cymbopogons, belonging to the aromatic genus Cymbopogon of the angiosperms, are an attractive 

plant resource for the aroma industry because of their ability to grow under diverse environments, 

possession of significant chemical polymorphism in their essential oils, and the ease of 

low-input cultivation in even the most neglected rural setting (Croteau and Gershenzon 1994; Khanuja 

et al. 2005). The cymbopogons, despite their perennial nature coupled with erratic flowering and 

135


seed-setting behavior, an extremely narrow genetic base, and high susceptibility to environmental 

stress, constitute a storehouse of useful terpenes of high premium that value make these aromatic 

grasses an ideal candidate for biotechnological prospecting and scrutiny. Biotechnological 

approaches that are being vigorously pursued in Cymbopogon species today include the following: 

(1) somaclonal breeding for varietal improvement, (2) in vitro cloning of elites, (3) molecular 

taxonomy, (4) enzymatic/genetic dissection of the biogenetic pathways associated with terpenoid 

synthesis, (5) isolation, cloning, and expression of pathway related genes, (6) production of designer 

genotypes through pathway engineering and transgenic route, and (7) high-throughput screening of 

various constituents of the essential oils for novel bioactivities and their diversified usage (Mathur 

et al. 1988a, 1988b; Sreenath and Jagadishchandra 1991; Patnaik et al. 1999; Fiehn 2002; Hall et al. 

2002; Khanuja et al. 2005; Oksman-Caldentey and Saito 2005; Shasany et al. 2007; Kumar et al. 

2007a, 2007b; Tyo et al. 2007; Edris 2007; Gomez-Galera et al. 2007). 

This chapter provides an overview of the developments in biotechnological research carried out 

in Cymbopogon species over the last two decades. An attempt has also been made here to highlight 

the unaddressed or unfinished challenges in the study of this important group of aromatic grasses 

that plant biotechnologists should take up first. 

4.2 Cymbopogon: the aromatIc genus 

Stapf (1906) gave Cymbopogon the status of genus under the tribe Andropogoneae of the family 

Poaceae. Taxonomically, 140 species of Cymbopogon are known today. They have been classified 

into three series: Schoenanthi, Rusae, and Citrati (Soenarko 1977). Members of these three series 

are distinct in possessing thin, subcordate, or lanceolate type of leaves, respectively. Nearly 60 

species of Cymbopogon are odoriferous grasses that are naturally adapted to hot-moist regions 

of the oriental tropics, subtropical Africa, and Southeast Asia (Jagadishchandra 1975; Soenarko 

1977; Robbins 1983; Sreenath and Jagadishchandra 1991; Kuriakose 1995; Shasany et al. 2000). 

Most of the Cymbopogon species are recognized by the characteristic odor note of their essential 

oils. Lemongrass oil, citronella oil, palmarosa oil, gingergrass oil, and karnkusa oil obtained from 

C. flexuosus and C. winterianus, C. martinii var. motia/C.martinii var. sofia, and C. jwarancusa, 

respectively, are the five most widely traded essential oils in the aroma sector. 

Endowed with a differential blend of more than 50 terpenoidal constituents, these oils are in 

high demand in the aroma industry as a perfumery agent per se or as a source of lead molecules to 

derive more useful value-added products required for high-grade cosmetics or drugs. For example, 

lemongrass oil, which is used in a range of industrial products where a lemon flavor is required, can 

also provide citral that can be modified into β-ionone and methyl-ionone and serves as a starting 

precursor for vitamins A and E synthesis (Robbins 1983). Similarly, citronella oil is a basic ingredient 

in soaps and mosquito-repellent preparations, and is also a good source of citronellal, which can 

impart a lily aroma upon hydroxylation or can be converted into l-menthol for the toothpaste industry. 

Likewise, palmarosa oil rich in geraniol often fetches a high price as a permissible adulterant of 

costly rose oil. Tremendous value addition can be made in geraniol by converting it into nerol and 

laevo-citronellol (Thapa et al. 1971; Maheshwari and Mohan 1985). The essential oil of gingergrass 

is a good source of perillyl alcohols, which can be chemically converted into perillyl acetate to get 

a spearmint aroma (Zutchi 1982). Karnkusa oil from C. jwarancusa is used for its antipyretic and 

asthmolytic activity. Piperitone obtained from this oil can now be synthetically converted into thymol 

to fetch very high returns (Shasany et al. 2007). 

Among the six commercially cultivated species of Cymbopogon, namely, C. flexuosus (East 

Indian lemongrass), C. winterianus (Java citronella), C. martinii (palmarosa), C. nardus (Ceylon citronella), 

C. citratus (West Indian lemongrass), and C. pendulus (North Indian lemongrass), the first 

three are most widely used as a primary source of citral, geraniol and citronellol, citronellal, linalool, 

1,8-cineole, limonene, beta-caryophyllene, geranyl acetate, and geranyl formate in the perfumery 

world (Sobti et al. 1982; Sharma and Ram 2000; McGarvey and Croteau 1995; Aharoni et al.

Biotechnological Studies in Cymbopogons 137 

2005). The majority of these cultivated species are predominantly propagated through vegetative 

slips, except C. martinii, which is multiplied by transplanted seedlings. However, seed progeny thus 

raised in case of C. martinii show a lot of heterogeneity because of its outcrossing nature (Soenarko 

1977) and, hence, vegetative propagation is also resorted to in this species when clonal multiplication 

is desired. 

Essential oil content in Cymbopogon species has been shown to be a quantitative trait with a high 

degree of narrow sense heritability and distinct coinheritance and correlation patterns with other 

plant traits such as height, tiller number, biomass yield, etc. (Kulkarni 1994; Kole 1985; Kulkarni 

and Rajgopal 1986; Sharma and Ram 2000; Tripathy et al. 2007). As a result of these tight linkages, 

coupled with problems associated with erratic flowering and seed setting, traditional breeding 

methods are often found inadequate to fix genes through selfing to develop a superior genotype 

in Cymbopogon species. Genetic improvement in these grasses is therefore confined to recurrent 

selection and introduction of superior clones out of the vegetative populations. Though a few workers 

have resorted to induced mutation breeding approach, success has been limited and the genetic 

advantage was meager (Sharma and Ram 2000). 

4.3 bIotechnologIcal studIes In cymboPogons 

4.3.1 ti s s u e Cu lt u r e st u d i e s 

On account of the problems associated with their difficult reproductive behavior in applying traditional 

breeding approaches, the genetic base of cymbopogons is shrinking at a fast pace. Comple 

mentation of these limited breeding options with modern tools of plant biology was, therefore, 

considered necessary in the early 1980s and the first biotechnological tool pressed into the service 

was plant tissue culture (Jagadishchandra 1982; Jagadishchandra and Sreenath 1986; Mathur et al. 

1988a, 1988b, 1989a; Yadav et al. 2000; Zheng et al. 2007). In the initial phase, tissue culture 

techniques were applied to standardized methods for in vitro cloning of elite selections via axillary 

shoot culturing in C. martinii, C. nardus, C. citratus, and C. jwarancusa (Jagadishchandra 1982). 

Both rhizome and nodal explants readily responded on a hormone-free Murashige and Skoog (1962) 

medium. Additional supplementation of 6-benzyladenine in the medium at the 0.1–0.5 mg/L level 

was found beneficial for the growth of 5–8 new leaves from the preformed meristems present in the 

explants in 3–4 weeks’ time. 

The focus of the plant tissue culturist was then shifted toward the callus cultures, with two primary 

goals: (1) to develop somatic embryogenesis-based rapid clonal propagation system and (2) to enhance 

the spectrum of variability through in vitro mutagenesis, followed by calli cloning to produce somaclonal 

variations for desired traits. A variety of explants such as zygotic embryos, mesocotyl pieces 

of seedling, stem, rhizome, and leaf sheath base were tested in different Cymbopogon species for 

the purpose of callus induction (see Sreenath and Jagadishchandra 1991). MS, B5 (Gamborg et al. 

1968), and LS (Linsmaier and Skoog 1965) basal media were found suitable for inducing a callus 

response from these explants. Young unemerged inflorescences with early stages of flower ontogeny 

were also found to be responsive for callus initiation in C. martinii (Baruah and Bordoloi 1989). 

Most of the workers faced initial problems in initiating an axenic culture in Cymbopogon species. 

Leaching of phenolics from the injured ends of the explants and high degree of contamination due 

to endophytic microbes present deep inside the explants were the two major hurdles encountered. 

Addition of antioxidants such as ascorbic acid (40–80 mg/L) in the callus initiation medium and 

frequent shifting of explants onto the fresh medium during the initial 2 weeks of culturing were 

found to be very effective in circumventing the problem of browning of explants (Mathur et al. 

1988a, 1989a). These workers also showed that soaking of explants in aqueous solution of 50 mg/L 

chloramphenicol for 8–12 h prior to their plating on the culture medium could also bring about a 

reduction in contamination frequency. Among the various growth regulators tested, 2,4-dichlorophenoxyacetic 

acid (2,4-D) at 1.0–5.0 mg/L was found to be most effective in eliciting a callus


response in cymbopogons. BAP and α-naphthaleneacetic acid (NAA) at low doses (0.1–1.0 mg/L) 

in 2, 4-D containing medium were often found helpful in making the induced callus organogenetic 

in subsequent passages. Once induced, the callus of all Cymbopogon species was found to be very 

fast proliferating with high regenerative potential (Mathur et al. 1988a, 1988b; Nayak et al. 1996; 

Patnaik et al. 1999). Considering the reports published on callus induction in Cymbopogon species 

so far, the leaf sheath base and seedling explants were found most totipotent for this response. 

Mature leaves, young rolled leaves, and internodal stem explants were found least responsive. Callus 

initiated from former set of explants normally sustained their regeneration potential for a longer 

time (2–4 years). Callus originating from rhizome pieces, on the other hand, depicted a very low 

organogenetic potential. 

Callus cultures of cymbopogons normally showed two types of morphology: (1) organogenic and 

(2) nonorganogenic. The organogenic callus is usually nodular, fragile, yellowish, and opaque in 

external appearance, whereas their nonorganogenic counterpart is nonnodular, pale white, slimy, and 

translucent (Mathur et al. 1989a; Jagadishchandra 1982; Sreenath and Jagadishchandra 1989, 1991). 

Nonorganogenic calli are further characterized by the presence of loosely arranged isodiametric 

parenchyma. In comparison, the organogenic callus has a central core of parenchyma surrounded by 

a peripheral nodular zone consisting of meristematic cells. Friable callus also goes fast into a suspension 

mode (Sreenath and Jagadishchandra 1980; Patnaik et al. 1995, 1996, 1997, 1999). A 1:5 dilution 

every 2–3 weeks was found suitable for maintaining these suspension cultures in vitro. 

High-frequency regeneration of somatic embryos or adventive shoot buds is a common occurrence 

in Cymbopogon calli. While C. martinii and C. citratus calli predominantly regenerate via 

the somatic embryogenic route, C. winterianus callus showed a regeneration mode involving de 

novo formation of shoot bud primordia (Nayak et al. 1996; Patnaik et al. 1999; Mathur et al. 1988a). 

Cymbopogon jwarncusa calli showed both routes of plant regeneration. Though regeneration can 

often occur on the callus multiplication medium itself, removal of 2,4-D from the media was found 

essential in some Cymbopogon species (Mathur et al. 1989a, 1989b). These workers observed that 

C. winterianus callus cultures did not enter the shoot regeneration stage unless they were shifted from 

2,4-D containing medium to a medium supplemented with 3-indole acetic acid (IAA) and BAP or 

kinetin (Kn). The regenerated shoots showed root initiation on the shoot multiplication medium, but 

a short exposure of individually excised shoots on medium with 0.1–0.5 mg/L NAA or IAA alone 

was found to enhance the root quality and subsequent establishment of plantlets in soil (Mathur 

et al. 1988a, 1988b). Following these protocols, efficient plant regeneration has been reported in palmarosa 

grass (Baruah and Bordoloi 1989; Patnaik et al. 1995, 1997, 1999). Plants derived through 

somatic embryos, in general, showed better genetic uniformity in comparison to those obtained 

through shoot bud organogenesis. Though a few workers have also reported a wide range of chromosomal 

variations in palmarosa callus (Patnaik et al. 1996; Sreenath and Jagadishchandra 1991) 

but embryogenesis and subsequent plantlet regeneration were found to occur from cells with normal 

diploid constitution only. These protocols have been employed for large-scale clonal propagation of 

this aromatic herb and have important implications for in vitro maintenance of inbreds and male 

sterile lines of palmarosa for harnessing the hybrid vigor inbreeding program involving sexual 

hybrids, synthetics, and composites (Ahuja et al. 2000). Nayak et al. (1996) reported a method 

of rapid in vitro propagation in C. flexuosus through somatic embryogenesis. Somatic embryos 

were formed on callus cultures grown on MS medium with 5.0 mg/L 2,4-D, 0.1 mg/L NAA, and 

0.5 mg/L Kn. Embryo-to-plantlet conversion occurred on medium supplemented with 3.0 mg/L 

BAP, 1.0 mg/L GA 3, and 0.1 mg/L NAA. The regeneration potential of these lemongrass cultures 

was stably sustained for >2 years. These somatic embryo-derived plants, when examined under field 

conditions, did not show any significant variation over the base material. 

The scope and potential of tissue culture technology for widening the narrow genetic base in 

cymbopogons was first demonstrated from the author’s laboratory (Mathur et al. 1988a). Realizing


the constraints of applying conventional breeding systems (sexual mating and recombination 

through meiosis) to create variability in C. winterianus, our group at CIMAP initiated an attempt 

to exploit the tools of somaclonal breeding in this grass. Conceptualized by Larkin and Scowcroft 

(1981) in wheat and sugarcane, somaclonal variations are defined as variations that arise in vitro 

during the culturing of a somatic cell or tissue. Such phenotypic variations generally result either 

from the preexisting genetic variability in the explants or through meiotically stable epigenetic 

DNA modifications induced by the culture environment (Philips et al. 1994; Bajaj 1990; Duncan 

1997). Cryptic chromosomal changes and change in degree of DNA methylation during culturing 

have been found to be the main factors behind such variations. In our study in citronella, more than 

700 callus-derived plantlets (regenerated through adventive shoot buds) were screened under field 

conditions, out of which 230 calli clones were advanced to plant to row stability assessment for 

several productivity-linked traits such as herb yield, tiller number, diameter of the bush, dry-matter 

production, and essential oil content. Variations were also recorded for six important constituents of 

the oil, namely, citronellal, citronellol, geraniol, citronellylacetate, geranylacetate, and elemol (the 

negative component in the oil). Correlation analysis between these agronomic characters indicated 

a strong negative linkage between herb yield and oil content. 

Interestingly, we could recover five somaclones with high herb and high oil content, showing 

thereby that even tight genetic linkages can be broken through somaclonal variation. Recurrent testing 

of five high herb and oil content bearing type clones at different locations ultimately led to the 

release of a somaclone (designated CIMAP/Bio-13) as India’s first plant variety improved through 

the somaclonal breeding approach. This variety has shown wide climatic adaptability in rainfed 

to subtropical to hot and moist conditions. Beside other agronomic traits of commercial importance, 

the variety registered a remarkable improvement in the initial establishment frequency of 

its vegetative slips (>85% in comparison to


2007; Jullien 2007; Shasany et al. 2007; Tyo et al. 2007; Xu and Crouch 2008). Such molecular 

markers today find extensive usage in settling taxonomic controversies and phylogenetic analysis of 

closely similar taxa. Besides, use of these DNA markers can also help plant breeders in their varietal 

development programs through marker-assisted selection of desired genotypes with a designed 

combination of genes that control the yield and quality traits (Khanuja et al. 1999; Sangwan and 

Sangwan 2000; Aharoni et al. 2006; Kumar et al. 2007a, 2007b; Xu and Crouch 2008). These DNA 

markers can, therefore, enhance the speed of any hybridization or transgenomic program aimed at 

producing designer specialty crops. 

Due to their large number and wider occurrence coupled with a prevalent introgressive hybridization 

mechanism, the precise phylogenetic identification of Cymbopogon species has always 

been a difficulty (Jagadishchandra 1975; Khanuja et al. 1999, 2005; Sangwan and Sangwan 2000; 

Sangwan et al. 2000; Shasany et al. 2000, 2007; Sharma and Ram 2000; Kumar et al. 2007a, 

2007b). Primary taxonomic delimitation is basically based on chemotaxonomic differences 

between the species. Isozyme patterns have also been employed to demarcate Cymbopogon species 

(Ganjewala and Luthra 2007). According to Shasany et al. (2007), the genus Cymbopogon is 

today known to have 140 species. Out of these, 52 are described from Africa, 45 from India, 6 each 

from Australia and South America, 4 from Europe, and the remaining species are distributed in 

different parts of Southeast Asia. A literature survey of taxonomy of the Cymbopogon species 

indicates that many species were classified on the basis of their morphological and oil quality 

profile alone. Information on their phylogenesis has been obscure. Distinct chemical features of 

otherwise morphologically similar C. martinii var. sofia and C. martinii var. motia on the one hand 

and morphologically distinct but chemically identical C. citratus and C. flexuosus on the other 

are typical examples of the complexity of such phenotypic/chemotaxonomic classification. Such 

an approach may lead to erroneous identity and evolutionary relationships between Cymbopogon 

species. Addressing this critical issue, Shasany et al. (2000, 2007) and Khanuja et al. (2005) conducted 

a detailed study to establish the ancestry of several Cymbopogon members. Phylogeny was 

traced by construction of RAPD/AFLP maps. These workers could successfully estimate the extent 

of molecular diversity among 19 Cymbopogon taxa belonging to 11 taxonomically classified species, 

2 released varieties, 1 hybrid taxon, and 4 unidentified wild collections (Khanuja et al., 2005). 

Citral content was employed as a base marker for chemotypic clustering. Based on their results, 

the workers have proposed the elevation of C. flexuosus var. microstachy to a separate species 

level. They also concluded that C. travancorensis, which was earlier merged with C. flexuosus, 

also deserves a separate species status. Their data also substantiated the independent species status 

for sofia and motia varieties of C. martinii. Several unidentified wild collections included in this 

molecular tagging work also required a separate taxonomic identity as intermediate forms in the 

evolution of new taxa. 

Advancing the scope of molecular markers for assigning phylogenetic relationships between different 

species of Cymbopogon, Kumar et al. (2007a, 2007b) have recently reported the development 

of a set of simple sequence repeat (SSR) markers. They used a genomic library of C. jwarancusa to 

develop these markers for the precise identification of Cymbopogon species up to the accession level. 

The SSRs containing genomic DNA clones of C. jwarancusa contained a total of 32 SSRs with a 

range of 1–3 SSRs per clone. About 68.8% of the 32 SSRs had dinucleotide repeat motifs, followed 

by 21.8% SSRs with trinucleotide and other higher-order repeat motifs. Eighteen of the 32 designed 

primers for the SSRs, amplified the products to anticipated sizes when tried with genomic DNA 

of source species C. jwarancusa. Thirteen of these 18 functional primers detected polymorphism 

among C. flexuosus, C. pendulus, and C. jwarancusa and amplified a total of 95 alleles with a PIC 

value of 0.44 to 0.96 per SSR. The workers have postulated that higher allelic range and high level 

of polymorphism depicted by these SSRs can be put to use in a variety of applications in genetic 

improvement of Cymbopogon species through genotype/species authentication and mapping or tagging 

the genes controlling the productivity-linked traits in marker-assisted breeding endeavors.


4.3.3 Me ta b o l iC en G i n e e r i nG st u d i e s 

Metabolic engineering is a relatively new area of plant biotechnology research; the term was coined 

for the first time by Bailey (1991). The concepts in metabolic engineering normally revolved around 

the identification of the major limiting blocks in the synthesis and accumulation of a desired plant 

metabolite, followed by systematically removing these blocks with the help of gene manipulation 

options available today (Verpoorte and Alfermann 2000; Endt et al. 2002; Martin et al. 2003; Horn 

et al. 2004; Liao 2004; Koffas and Cardayre 2005). Three conditions must be met in a plant (cell) 

before a significant increment in the biogenesis of a metabolite can be expected to occur. They are 

(1) induction of genes/enzymes involved in the targeted metabolic pathway at right time and place; 

(2) availability and supply of the precursors has to be assured; and (3) there should be sufficient 

sink capacity for storage of the desired metabolite (Mathur et al. 2006). Since the primary goal in 

a metabolic engineering effort is to divert or channelize the pathway flux toward the synthesis and 

accumulation of a required phytomolecule, the experimental approaches that are the focus of such 

a program include the following: 

1. Downregulation of the flux in undesired route at branch points of a pathway by antisense 

or RNAi approach 

2. Overexpression of rate-limiting enzyme 

3. Decrease catabolism of end products 

4. Increase in metabolite-producing or metabolite-storing cell types 

5. Manipulation of regulatory elements acting as transcriptional activator/repressor of several 

genes associated with the target pathway 

6. Generation of heterologous expression systems capable of operating minipathways of 

a broad complex, multistep pathway to obtain intermediates that can be converted into a 

desired molecule using tools of semisynthetic chemistry or cell-free biotransformations. 

Metabolic engineering, therefore, is a sum of all the optimization efforts, culminating in the upgradation 

of a required biochemical/genetic expression of a phenotype in a defined genotypic background 

(Tyo et al. 2007). Evidence from the protein engineering and system biology approaches 

are further advancing the precision of metabolic engineering experiments in plants. Clearly, the 

pathway manipulation strategies are now evolving from single-gene perturbation to global transcription 

machinery engineering (gTME). The coming years will see more and more focus on 

those phytomolecules that are exceptionally costly, are exclusively of plant origin, and that otherwise 

defy the rules of synthetic chemistry due to complex chirality (Hall et al. 2002; Fiehn 2002; 

Brent 2004; Oksman-Caldentey and Saito 2005; Yonekura-Sakakibara and Saito 2006; Hall 2006; 

Gomez-Galera et al. 2007). It is, therefore, no surprise that plant terpenoids are attracting most 

attention from metabolic engineers (Verpoorte et al. 2000; Verpoorte and Memelink 2002; Trapp 

and Croteau 2001; Wallaart et al. 2001; Mahmoud and Croteau 2002; Schijlen et al. 2004; Akhila 

2007; Chang et al. 2007; Petersen 2007). Initial efforts have indicated that multiple-step terpene 

pathway engineering across several cellular compartments is feasible (Aharoni et al. 2005). 

An enormous wealth of information on chemistry, biological activity, synthesis, and regulation 

of plant terpenoid metabolism exists in the literature (Akhila 1985, 1986; Croteau and Gershenzon 

1994; Penuelas et al. 1995; McGarvey and Croteau 1995; Dixon et al. 1996; Lichtenthaler 1999; 

Verpoorte et al. 2000; Hallahan 2000; Bourgaud et al. 2001; Eisenreich et al. 2001; Trapp and 

Croteau 2001; Pichersky and Gershenzon 2002; Holopainen 2004; Cheng et al. 2007). Terpenoids, 

in general, are a structurally varied class of natural products that are commercially in demand 

as flavoring, perfumery, pharmaceuticals, insecticidal, and antimicrobial agents (Martin et al. 

2003). In plants, they play important roles in plant–plant, plant–environment, and plant–microbe 

or plant–insect interactions, and impart an ecological fitness to a plant (Aharoni et al. 2005, 2006).


A generalized scheme of biosynthesis of terpenoidal molecules starts with the condensation of isopentyl 

diphosphate (IDP) and its allylic isomer dimethyl-allyl diphosphate (DMADP). The sequential 

head-to-tail addition of IDP units with DMADP yields geranyl diphosphate (GDP), farnesyl 

diphosphate (FDP), and geranylgeranyl diphosphate (GGDP). Under the influence of synthases or 

cyclases, these three metabolites then serve as starting precursors for mono-, sesqui-, and diterpenoids, 

respectively. The terminal decoration of the basic terpenoidal skeleton is brought about by an 

array of substitution reactions such as hydroxylation, dehydrogenation, reduction, glucosylation, and 

methyl or acyl transfers to generate the wide spectrum of terpenoid diversity that we encounter in 

plants. Terpenoid biosynthesis occurs both in the cytosol and the plastids via mevalonate and MEP 

pathways, respectively (Lichtenthaler 1999; Eisenreich et al. 2001; Wallaart et al. 2001; Akhila 

2007; Cheng et al. 2007). 

A literature survey of metabolic engineering efforts in Cymbopogon species reflects a vacuum. 

This is partly because of the difficulty associated with the DNA isolation and genetic transformation 

protocols in these grasses (Khanuja et al. 1999). Since upstream steps of terpenoid biogenesis 

in Cymbopogon species are the same as those in other aromatic plants such as mints, and sufficient 

knowledge of their in vitro handling is available today, it may be anticipated that the void will be 

filled soon. According to Sangwan and Sangwan (2000), application of metabolic tools in cymbopogons 

would find increasing attention in the following three areas: 

1. Bringing alterations in magnitude of flux of pyruvate and glyceraldehydes-3 phosphate 

toward isopentenyl pyrophosphate (IPP) generation. 

2. Modulation of geranyl pyrophosphate synthase or farnesyl pyrophosphate synthase, or their 

overexpression, to divert the flux toward monoterpene or sesquiterpene accumulation. 

3. Secondary modification of parental terpene molecules via individual or a combination of 

isomerization, reduction, oxidation, lactonization, or epoxidation reaction to derive valueadded 

phytomolecules with enhanced organoleptic or pharmaceutical properties. 

Coining a new term terpenomics to refer to the ongoing metabolic engineering approaches in aroma 

crops, Khanuja (2003) also emphasized the need to focus on modulation of terpene synthases’ class 

of enzymes in Cymbopogon and Mentha species to facilitate unique regiochemical/stereochemical 

configuration in intermediates of terpene metabolism to derive newer activities. It is hoped that 

these new bioactives will equip our plants with improved disease resistance, weed/pest control, and 

more powerful pollination mechanism. 

4.4 Future oPtIons In bIotechnology oF cymboPogons 

Avenues for future research in the biotechnology of Cymbopogon species are enormous. Some of 

the areas that demand priority efforts are discussed below to ignite the excitement of, and the challenges 

for, future researchers: 

• Somaclonal breeding work in Cymbopogon species deserves more scrutiny and attention. 

With the documented success story of CIMAP/Bio-13 variety of citronella Java in the kitty, 

future efforts should be specifically focused on enhancing the volumetric yield of important 

essential oils and their industrially important pure constituents. Cultivars resistant 

to water stress or flooding stress are required to utilize Cymbopogon species in marginal 

lands or wasteland. Somaclones with better resistance to nutritional and microbial diseases 

are required through directed in vitro mutagenesis and cell line selections. 

• A sound understanding of handling Cymbopogon species in tissue cultures can also be 

put to use in understanding the influence of microbial associations on expression of the 

biogenetic pathways in these grasses. In vitro tissues maintained at different morphogenetic 

levels (callus, cell suspensions, shoots, roots, or whole plantlets) would not only


permit a better understanding of the role of tissue differentiation in advancing the pathway 

but would also provide the ideal aseptic scenario to assess the influence of individual 

micro organisms (isolated from plants’ rhizosphere) on essential oil synthesis following 

their deliberate incorporation in the cultured tissue. One such effort has recently made 

in Vetiveria zizanioides (vetiver). This study by DelGuidice et al. (2008) has opened up 

an entirely new avenue for research in aromatic grasses. Using a tissue culture approach, 

these workers have reported that essential oil biosynthesis in vetiver is confined to the first 

cortical layer outside the root endodermis that also harbors a community of 10 endophytic 

bacteria. When these bacteria were cultured on medium containing vetiver oil as sole carbon 

source, they were able to metabolize the oil, and each endophyte was able to release 

into the medium a large number of derivatives that were absent in the raw oil fed to them. 

Besides opening a new line of investigation on in vitro bioconversions, this approach will 

be useful in understanding the microbial factors responsible for the final expression of 

essential oil quality in Cymbopogon plants. 

• Another potentially fruitful area of research in the biotechnology of cymbopogons would be 

the time course analysis of volatile terpene emission in the headspace of the culture vessels 

(Tholl et al. 2006; Predieri and Rapparini 2007). This can prove to be a powerful nondestructive 

method of monitoring the physiological status of the plants in relation to the synthesis of 

the oil constituents under a controlled environment (Alonzo et al. 2001). The biogenic emission 

of terpenes in field-grown plants has been found to be associated with oxidative chemistry 

of the surrounding environment and the plant itself. It will be interesting to trace these volatile 

emission changes following various stress and/or elicitation treatments given to a controlled 

culture in vitro (Maes and Debergh 2003; Loreto et al. 2006; Sharkey and Yeh 2001). 

• Most of the Cymbopogon species, similar to other aromatic crops, synthesize their essen- 

tial oils in the epidermal cells of the leaves and store the synthesized oil in glandular 

trichomes (Shankar et al. 1999; Hallahan 2000). It is probably this tight linkage between 

oil synthesis and tissue differentiation that has deterred researchers from exploiting cell 

culture approaches for in vitro metabolite production in these species. However, with recent 

advancements made in the molecular understanding of terpenoidal pathways in plant and 

refinements in cell culture technology, it is desirable to revisit this research area (Tisserat 

and Vaughan 2008). Since microshoots of cymbopogons reared in vitro also depict this tissue 

specialization, a modest beginning can be made by upscaling them in bioreactors for 

harvesting of desired metabolite. Such an in vitro production system will be particularly 

relevant for producing oil constituents that are otherwise synthesized in very low amounts 

in plants. Alternately, they can be used for the production of a single predominant terpene, 

as has been done for (−) carvone in Mentha spicata (Jullien 2007). Until this stage 

is reached with cymbopogons, the cell cultures of aromatic grasses must be vigorously 

screened as a source of common enzymes and intermediates of terpene metabolism to 

carry out useful biotransformation for value addition of aroma phytoceuticals. 

• In spite of major advances made in tissue culturing of Cymbopogon species, no effort 

• 

has so far been made to standardize transgenic protocols in these grasses. It seems to be 

more of a mental block rather than a technical hurdle. Development of an efficient somatic 

embryogenic-based transformation method in cymbopogons must be attempted to realize 

the full potential of “-omic” research. 

Anther and pollen culture is another research area that can complement conventional breeding 

work in cymbopogons. Haploid plants thus produced will be of immense utility for producing 

inbred lines and for inducing desired mutations in seed-propagated Cymbopogon species. 

• Chemomolecular prospecting of various essential oil constituents of Cymbopogon species 

to devise new therapeutics has enormous potential (Delespaul et al. 2000; Ojo et al. 2006; 

Adeneye and Agbaje 2007; Agbafor and Akubugnov 2007; Shen et al. 2007; Masuda et al.


2008). Essential oils of these grasses are already in use in aroma therapies (see Edris 2007). 

The bioactivities found to be associated with these oils ranged from antibacterial to antiviral, 

antioxidant, and antidiabetic to antineoplastic. Their capacity to enhance the permeability 

of stratum corneum of human skin makes them a good adjuvant in transdermal drug 

delivery formulations (Williams and Barry 2004). Citral, a major constituent of lemongrass 

oil, has been found to be a potent inducer of glutathione-s-transferase class of enzymes, 

which provide protection to healthy hepatocytes against apoptosis during chemo therapy 

of liver cancers (Nakamura et al. 2003). This protective capacity of citral was, however, 

confined to its trans configuration (geraniol) only. Its cis configuration (neral) had no such 

effect. Selection of plant cells capable of converting cis configuration to trans form should 

be an exciting goal for plant/microbial biotechnologists. Another constituent of lemongrass 

oil, namely, perillyl alcohol (POH), which is a hydroxylated analog of d-limonene, is also 

gaining a lot of attention as a powerful radio-sensitizer of tumor cells. It can drastically 

reduce the radiation doses to control breast, colon, and prostrate cancers (Duetz et al. 2003; 

Rajesh et al. 2003). Geraniol, the primary constituent of palmarosa grass, has been found 

to make tumor cells vulnerable to 5-flurouracil (5-FU) by reducing the activity of thymidylate 

synthase and thymidine kinase, which are responsible for 5-FU toxicity in mice. 

Bioprospection of essential oils of Cymbopogon species would yield agents against several 

plant and human pathogens such as Salmonella, Staphylococcus, Shigella, Aspergillus, 

Fusarium, Penicillium, etc. (Burt 2004; Wannissorn et al. 2005; Cimanga et al. 2002; 

Pandey et al. 2003). Bankole and Joda (2004) have reported that a very effective method 

of controlling storage deterioration of melon seeds due to Aspergillus species is mixing 

the seeds with powdered dry leaves of lemongrass (C. citratus). Complete inhibition of A. 

flavus and A. niger was realized, and the efficacy was found to be at par with fungicide 

(iprodione) treatment. Similarly, Duamkhanmanee (2008) has shown the total control of 

postharvest anthracnose disease of mango fruit caused by Colletotrichum gloeosporioides 

by C. citratus oil (4000 ppm in hot water). The anthracnose disease of cowpea crop in the 

field was demonstrated to be controlled by cold water leaf extract of lemongrass (Amadioha 

and Obi 1999). Lemongrass oil has also been shown to inhibit growth of Candida albicans 

at 2.0 µL/mL level in the culture medium (El-Khair 2007). Oil treatment kills the microbial 

cells due to enhanced K + depletion from the cells following a fall in membrane lipid 

content. A similar inhibitory mechanism was also observed in Saccharomyces cerevisiae 

challenged with geraniol of palmarosa oil. 

The mechanisms by which essential oils of Cymbopogon species inhibit microbial 

growth are far from completely understood. Their hydrophobicity has often been cited 

as a possible mode of action that helps them to get partitioned into the lipid bilayer of the 

microbial cell membrane, making it permeable enough to allow leakage of vital cellular 

content (Burt 2004; Pattnaik et al. 1997; Delaquis et al. 2002; Prashar et al. 2003). There 

is tremendous scope to advance this research at enzymatic and molecular levels to develop 

more ecofriendly and safe bioprotectants for plant and animal use. 


Biotechnological studies so far carried out in Cymbopogon species should be integrated now for 

synergism, coordination, and upscaling to derive commercial gains. Availability of efficient tissue 

culture protocols for plant regeneration on the one hand and fairly explicit understanding of the biosynthetic 

pathways of their essential oils at the level of genes and enzymes on the other have set the 

stage to move toward the redesigning of these aroma crops with transgenic approaches. It is hoped 

that the vast variety of high-value terpenes that these grasses can harbor and the exclusivity of the 

chemical reactions that their enzymatic and genetic machinery is capable of carrying out, both in 

planta and in culture, would motivate chemists and biologists alike to convert them into efficient


green bioreactors for aroma and pharmaceutical molecules in the near future. In vitro and in vivo 

bioprospecting of Cymbopogon species for deriving novel bioactives is another area that will keep 

the scientists intensely engaged with these aromatic grasses. 

reFerences 

Adeneye AA, Agbaje EO. 2007. Hypoglycemic and hypolipidemic effects of fresh leaf aqueous extract of 

Cymbopogon citratus Stapf. in rats. J Ethanopharmacol. 112: 440–444. 

Agbafor KN, Akubugwo EL. 2007. Hypocholesterelemic effect of ethanolic extract of fresh leaves of 

Cymbopogon citratus (lemongrass). African J. Biotechnol. 6: 596–598. 

Aharoni A, Jongsma MA, Bouwmeester HJ. 2005. Volatile science? Metabolic engineering of terpenoids in 

plants. Trends Plant Sci. 10: 594–602. 

Aharoni A, Jongsma MA, Kim T, Ri M, Giri AP, Verstappen FWA, Schwab W, Bouwmeester HJ. 2006. 

Metabolic engineering of terpenoid biosynthesis in plants. Phytochem. Review 5: 49–58. 

Ahuja PS, Mathur AK, Kukreja AK, Pandey B. 2000. Potential of plant tissue culture for the improvement of 

Cymbopogon species. In: Kumar S, Dwivedi S, Kukreja AK, Sharma JR, Bagchi, GD (Eds.), Cymbopogon: 

The Aromatic Grass: A Monograph, pp. 185–198. CIMAP (CSIR) Publication, Lucknow, India. 

Akhila A. 1985. Biosynthetic relationship of citral trans and citral cis in Cymbopogon flexuosus (lemongrass). 


Akhila A. 1986. Biosynthesis of monoterpenes in Cymbopogon winterianus. Phytochemistry 25: 421–424. 

Akhila A. 2007. Metabolic engineering of biosynthetic pathways leading to isoprenoids: Mono- and sesquiterpenes 

in plastids and cytosol. J. Plant Interact. 2: 195–204. 

Alonzo G, Saiano F, Tusa N, Del Bosco SF. 2001. Analysis of volatile compounds released from embryogeneic 

cultures and somatic embryos of sweet oranges by head space SPME. Pl. Cell Tiss. Org. Cult. 

66: 31–34. 

Amadioha AC, Obi VI. 1999. Control of anthracnose disease of cowpea by Cymbopogon citrates and Ocimum 

gratissimum. Acta Phytopathologica et Entomologica Hungarica 34: 685–690. 

Bailey JE. 1991. Towards a science of metabolic engineering. Science 252: 1668–1675. 

Bajaj YPS. 1990. Somaclonal variation—Origin, induction, cryopreservation and implication in plant breeding. 

In: Bajaj YPS (Ed.) Biotechnology in Agriculture and Forestry, Vol 11: Somaclonal variation in crop 

improvement, pp. 3–48. Springer-Verlag, Berlin. 

Bankole SA, Joda AO. 2004. Effect of lemon grass (Cymbopogon citrates Stapf.) powder and essential oil on 

mould deterioration and aflatoxin contamination of melon seeds (Colocynthis citrullus L.). African J. 

Biotechnol. 3: 52–59. 

Baruah A, Bordoloi DN. 1989. High frequency plant regeneration of Cymbopogon martini (Roxb.) Wats. by 

somatic embryogenesis and organogenesis. Pl. Cell Rept. 8: 483–485. 

Bourgaud F, Gravot A, Milesi S, Gontier E. 2001. Production of plant secondary metabolites: A historical perspective. 

Pl. Sci. 161: 839–851. 

Brent R. 2004. A partnership between biology and engineering. Nature Biotechnol. 22: 1211–1214. 

Burt S. 2004. Essential oils: their antibacterial properties and potential applications in food—A review. Intl. J. 

Food Microbiol. 94: 223–253. 

Chang MCY, Eachus RA, Trieu W, Ro D, Keasling JD. 2007. Engineering Escherichia coli for production of 

functionalized terpenoids using plant P-450s. Nature Chem. Biol. 3: 274–277. 

Cheng A, Lou Y, Mao Y, Lu S, Wang L, Chen X. 2007. Plant terpenoids: Biosynthesis and ecological functions. 

J. Integrative Pl. Biol. 49: 179–186. 

Cimanga K, Kambu K, Tona L, Apers S, DeBruyne T, Hermans N, Totte J, Pieters L, Vlietinck AJ. 2002. 

Correlation between chemical composition and antibacterial activity of essential oils of some aromatic 

plants growing in Democratic Republic of Congo. J. Ethnopharmacol. 79: 213–222. 

Croteau R, Gershenzon J. 1994. Genetic control of monoterpene biosynthesis in mints (Mentha: Lamiaceae): 

Genetic engineering of plant secondary metabolism. Recent Adv. Phytochem. 28: 193–229. 

Croteau R, Kutchan TM, Lewis NG. 2000. Natural products (Secondary metabolites). In: Buchana B, 

Gruissem W, Jones R (Eds.), Biochemistry and Molecular Biology of Plants, pp. 1250–1318. Amer. 

Soc. Pl. Pathologists, Rockville, Maryland. 

Datta SK. 2007. Impact of plant biotechnology in agriculture. In: Pua EC, Davey MR (Eds.), Biotechnology in 

Agriculture and Forestry, Vol. 59. Transgenic Crops IV, pp. 3–34. Springer-Verlag, Berlin, Heidelberg. 

Delaquis PJ, Stanich K, Girard B, Mazza G. 2002. Antimicrobial activity of individual and mixed fraction of 

dill, cilantro, coriander and eucalyptus essential oils. Intl. J. Food Microbiol. 74: 101–109.


Delespaul Q, de Billerbeck VG, Roques CG, Michel O. 2000. The antifungal activity of essential oils as determined 

by different screening methods. J. Essen. Oil Res. 12: 256–266. 

DelGiudice L, Massardo DR, Pontieri P, Bertea CM, Carata E, Tredici SM, Tala A, Destefamo M, Maffei M, 

Alifano P. 2008. The microbial community of vetiver root is necessary for essential oil biosynthesis. 

Proc. 52nd Italian Soc. Agric. Genet. Annual Cong., poster No. C.01, September 14–17, 2008, Italy. 

Dixon RA, Lamb CJ, Masoud S, Sewalt VJH, Paiva NL. 1996. Metabolic engineering: Prospects for crop 

improvement through the genetic manipulation of phenylpropanoid biosynthesis and defense responses— 

A review. Gene 179: 61–71. 

Duamkhanmanee R. 2008. Natural essential oils from lemongrass (Cymbopogon citrates) to control postharvest 

anthracnose of mango fruit. Intl. J. Biotechnol. 10: 104–108. 

Duetz W, Bouwmeester H, VanBeilent J, Witholt B. 2003. Biotransformation of limonene by bacteria, fungi, 

yeast and plants. Appl. Microbiol. Biotechnol. 61: 269–277. 

Duncan RR. 1997. Tissue culture induced variation and crop improvement. In: Sparks DL (Ed.), Advances in 

Agronomy, Vol. 58, pp. 201–210. Academic Press, London. 

Edris AE. 2007. Pharmaceutical and therapeutic potential of essential oils and their individual volatile constituents: 

A review. Phytother. Res. 21: 308–323. 

Eisenreich W, Rohdich F, Bacher A. 2001. Deoxyxylulose phosphate pathway to terpenoids. Trends Plant Sci. 

6: 78–84. 

El-Khair EK. 2007. Effect of Cymbopogon citrates L. essential oil on growth and morphogenesis of Candida 

albicans. Egyptian J. Biotechnol. 25: 145–158. 

Endt DV, Kijne JW, Memelink J. 2002. Transcription factors controlling plant secondary metabolism: What 

regulates the regulators?, Phytochemistry 61: 107–114. 

Fiehn O. 2002. Metabolomics—The link between genotypes and phenotypes. Pl. Mol. Biol. 48: 155–171. 

Galili G. 2002. Genetic, molecular and genomic approaches to improve the value of plant foods and feeds. Crit. 

Rev. Pl. Sci. 21: 167–204. 

Gamborg OL, Miller RA, Ojima K. 1968. Nutrient requirements of suspension cultures of soybean root cells. 

Exp. Cell Res. 50: 151. 

Ganjewala D, Luthra R. 2007. Identification of Cymbopogon species and C. flexuosus (Nees Ex. Steud.) Wats. 

cultivars based on polymorphism in esterases isoenzymes. J. Pl. Sci. 2: 552–557. 

Gomez-Galera S, Pelacho AM, Gene A, Capell T, Christon P. 2007. The genetic manipulation of medicinal 

and aromatic plants. Pl. Cell Rept. 26: 1689–1715. 

Hall R, Beale M, Fiehn O, Hardy N, Summer L, Bino R. 2002. Plant metabolomics: The missing link in functional 

genomics strategies. Plant Cell 14: 1437–1440. 

Hall RD. 2006. Plant metabolomics: From holistic hope to hype to hot topic. New Phytol. 169: 453–468. 

Hallahan DL. 2000. Monoterpenoid biosynthesis in glandular trichomes of Labiateae plants. Adv. Bot. Res. 31: 

77–120. 

Holopainen JK. 2004. Multiple functions of inducible plant volatiles. Trends Plant Sci. 9: 529–533. 

Horn ME, Woodard SL, Howard JA. 2004. Plant molecular farming: Systems and products. Pl. Cell Rept. 22: 

711–720. 

Jagadishchandra KS. 1975. Recent studies on Cymbopogon Spreng. (aromatic grasses) with special reference 

to Indian taxa: Taxonomy, cytogenetics, chemistry and scope. J. Plantation Crops 2: 43–57. 

Jagadishchandra KS. 1982. In vitro culture and morphogenetic studies in some species of Cymbopogon 

Spreng. (aromatic grasses). In: Fujiwara A (Ed.) Plant Tissue Culture, pp. 703, 704. Maruzen, Tokyo. 

Jagadishchandra KS, Sreenath HL. 1986. In vitro culture of rhizome in Cymbopogon Spreng and Vetiveria 

Bory. In: Reddy GM (Ed.) Proceedings of National Symposium on Recent Advances in Plant Cell and 

Tissue Culture of Economically Important Plants, pp. 199–208. Osmania University, Hyderabad, India. 

Jain N, Shasany AK, Sundaresan V, Rajkumar S, Darokar MP, Bagchi GD, Gupta AK, Khanuja SPS. 2003. 

Molecular diversity in Phyllanthus amarus assessed through RAPD analysis. Curr Sci. 85: 1454–1458. 

Jauhar PP. 2006. Modern biotechnology as an integral supplement to conventional plant breeding: The prospects 

and challenges. Crop Sci. 46: 1841–1859. 

Jullien F. 2007. Mints. In: Pua EC, Davey MR (Eds.), Biotechnology in Agriculture and Forestry vol 59. 

Transgenic Crops IV, pp. 435–466. Springer-Verlag, Berlin, Heidelberg. 

Khanuja SPS. 2003. Revisiting the fragrances—the terpenomics way. J. Med. Arom. Pl Sci. 25: 335. 

Khanuja SPS, Shasany AK, Darokar MP, Kumar S. 1999. Rapid isolation of DNA from dry and fresh samples of 

plants producing large amounts of secondary metabolites and essential oils. Pl. Mol. Biol. Rept. 17: 1–7. 

Khanuja SPS, Shasany AK, Pawar A, Lal RK, Darokar MP, Naqvi AA, Rajkumar S, Sundaresan V, Lal N, 

Kumar S. 2005. Essential oil constituents and RAPD markers to establish species relationship in Cymbopogon 

Spreng. (Poaceae). Biochem Syst. Ecol. 33: 171–186.


Koffas M, Cardayre SD. 2005. Evolutionary metabolic engineering. Metabolic Eng. 7: 1–3. 

Kole C. 1985. Improvement of Cymbopogon winterianus Jowitt. through mutagenesis. Ind. Perfumer 29: 

129–138. 

Kole C. 2007. Genome Mapping and Molecular Breeding in Plants, Vol. 6—Technical Crops (Ed.). Springer- 

Verlag, Berlin. 

Kulkarni RN, Rajagopal K. 1986. Broad and narrow sense heritability estimates of leaf yield, leaf width, tiller 

number and oil content in East Indian lemongrass. J. Pl. Breed. 96: 135–139. 

Kulkarni RN. 1994. Phenotypic recurrent selection for oil content in East Indian lemongrass. Euphytica 78: 

103–107. 

Kumar J, Verma V, Qazi GN, Gupta PK. 2007a. Genetic diversity in Cymbopogon species using PCR based 

functional markers. J. Pl. Biochem. Biotechnol. 16: 119–122. 

Kumar J, Verma V, Sahai AK, Qazi GN, Balyan HS. 2007b. Development of simple sequence repeat markers in 

Cymbopogon species. Planta Med. 73: 262–266. 

Kuriakose KP. 1995. Genetic variability in East Indian lemongrass (Cymbopogon flexuosus Stapf.). Ind. 


Larkin PJ, Scowcroft WR. 1981. Somaclonal variation—a novel source of variability from cell cultures for 

plant improvement. Theor. Appl. Genet. 60: 197–214. 

Liao JC. 2004. Custom design of metabolism. Nature Biotechnol. 22: 29–36. 

Lichtenthaler HK. 1999. The 1-deoxy-d-xylulose-5-phosphate pathway of isoprenoid biosynthesis in plants. 

Annu. Rev. Pl. Physiol. Pl. Mol. Biol. 50: 47–66. 

Linsmaier EM, Skoog, F. 1965. Organic growth factor requirement of tobacco tissue cultures. Physiol. Plant. 

18: 100–127. 

Loreto F, Batra C, Brilli F, Nogues I. 2006. On the induction of volatile organic compound emissions by plants 

as a consequence of wounding or fluctuation of light and temperature. Pl. Cell Environ. 29: 1820–1828. 

Maes K, Debergh PC. 2003. Volatiles emitted from in vitro grown tomato shoots during abiotic and biotic 

stress. Pl. Cell Tiss. Org. Cult. 75: 73–78. 

Maheshwari ML, Mohan J. 1985. Geranyl formate and other esters in palmarosa oil. Pafai J. 7: 21–26. 

Mahmoud SS, Croteau R. 2002. Startegies for transgenic manipulation of monoterpene biosynthesis in plants. 

Trends Plant Sci. 7: 366–373. 

Martin VJJ, Pitera DJ, Withers ST, Newman JD, Keasling JD. 2003. Engineering the mevalonate pathway in 

Escherichia coli for production of terpenoids. Nat. Biotechnol. 21: 1–7. 

Masuda T, Osaka Y, Ogawa N, Nakamoto K, Kuminaga H. 2008. Identification of geranic acid—a tyrosinase 

inhibitor in lemongrass. J. Agric. Food Chem. 56: 597–601. 

Mathur AK, Ahuja PS, Pandey B, Kukreja AK, Mandal S. 1988a. Screening and evaluation of somaclonal 

variations for quantitative and qualitative traits in an aromatic grass. Cymbopogon winterianus Jowitt. 

Pl. Breed. 101: 321–334. 

Mathur AK, Ahuja PS, Pandey B, Kukreja AK, Mathur A. 1988b. Development of superior strains of an aromatic 

grass Cymbopogon winterianus Jowitt, through somaclonal variation. In: Proc. International Conference on 

Research in Plant Sciences and its Relevance to the Future, p. 160. Delhi University Press, Delhi, India. 

Mathur AK, Ahuja PS, Pandey B, Kukreja A. 1989a. Potential of somaclonal variation in the genetic improvement 

of aromatic grasses. In: Kukreja AK, Mathur AK, Ahuja PS, Thakur RS (Eds.), Tissue Culture and 

Biotechnology of Medicinal and Aromatic Plants, pp. 79–90. Paramount Publishing House, New Delhi, 

India. 

Mathur AK, Ahuja PS, Kukreja AK, Pandey B, Mathur A. 1989b. Progress in the application of tissue culture 

for the improvement of aromatic grasses. In: Proc. XIII Annual Meeting of Plant Tissue Culture 

Association of India, pp. 31. North-Eastern Hill University, Shillong, India. 

Mathur AK, Mathur A, Seth R, Verma P, Vyas D. 2006. Biotechnological interventions in designing speciality 

medicinal herbs for 21st century: Some emerging trends in pathway modulation through metabolic engineering. 

In: Sharma RK, Arora R (Eds.), Herbal Drugs: A Twenty First Century Perspective, pp. 83–94. 

Jaypee Brothers Medical Publishers, New Delhi, India. 

McGarvey DJ, Croteau R. 1995. Terpenoid metabolism. Pl. Cell 7: 1015–1026. 

Murashige T, Skoog, F. 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. 

Physiol. Plant. 15: 473–497. 

Nakamura Y, Miyamoto M, Murakami A, Ohigashi H, Osawa T, Uchida R. 2003. A phase II detoxification 

enzyme inducer from lemongrass: identification of citral and involvement of electrophilic reaction in the 

enzyme induction. Biochem. Biophys. Res. Commun. 302: 593–600. 

Nayak S, Debata, BK, Sahoo S. 1996. Rapid propagation of lemongrass [Cymbopogon flexuosus (Nees) Wats.] 

through somatic embryogenesis in vitro. Pl. Cell Rept. 15: 367–370.


Ojo OO, Kabutu FR, Bello M, Babayo U. 2006. Inhibition of paracetamol-induced oxidative stress in rats 

by extracts of lemongrass (Cymbopogon citrates) and green tea (Camellia sinensis) in rats. African J. 

Biotechnol. 5: 1227–1232. 

Oksman-Caldentey KM, Saito S. 2005. Integrating genomics and metabolomics for engineering metabolic 

pathways. Curr. Opin. Biotechnol. 16: 174–179. 

Pandey AK, Rai MK, Acharya D. 2003. Chemical composition and antimycotic activity of the essential oils of 

corn mint (Mentha arvensis) and lemongrass (Cymbopogon flexuosus) against human pathogenic fungi. 

Pharmaceut. Biol. 41: 421–425. 

Patnaik J, Sahoo S, Debata BK. 1995. Somatic embryogenesis and cytological variations in long-term callus 

cultures of Cymbopogon martinii (Roxb.) Wats. An assessment. Pl. Sci. Res. 17: 1–5. 

Patnaik J, Sahoo S, Debata BK. 1996. Cytology of callus, somatic embryos and regenerated plants of palmarosa 

grass [Cymbopogon martinii (Roxb.) Wats.]. Cytobios. 87: 79–88. 

Patnaik J, Sahoo S, Debata BK. 1997. Somatic embryogenesis and plantlet regeneration from cell suspension 

cultures of Palmarosa grass (Cymbopogon martinii). Pl. Cell. Rept. 16: 430–434. 

Patnaik J, Sahoo S, Debata BK. 1999. Somaclonal variation in cell suspension culture-derived regenerants of 

Cymbopogon martinii (Roxb.) Wats. var. motia. Pl. Breed. 118: 351–354. 

Pattnaik S, Subramanyam VR, Bajpai M, Kole CR. 1997. Antibacterial and antifungal activity of aromatic 

constituents of essential oils. Microbios 89: 39–46. 

Pecchioni N, Faccioli P, Monetti A, Stanca AM, Terzi V. 1996. Molecular markers for genotype identification 

in small grain cereals. J. Genet. Breed. 50: 203–219. 

Penuelas J, Llusia J, Estiarte M. 1995. Terpenoids: A plant language. Trends Ecol. Evol. 10: 289. 

Petersen M. 2007. Current status of metabolic phytochemistry. Phytochemistry 68: 2847–2860. 

Philips RL, Kaepler SM, Olhoft P. 1994. Genetic instability of plant tissue cultures: breakdown of normal control. 

Proc. Natl. Acad. Sci. USA 91: 5222–5226. 

Pichersky E, Gershenzon J. 2002. The formation and function of plant volatiles: perfumes for pollinator attraction 

and defense. Curr. Opin. Pl. Biol. 5: 237–242. 

Prashar A, Hili P, Veness RG, Evans CE. 2003. Antimicrobial action of palmarosa oil (Cymbopogon martinii) 

on Saccharomyces cerevisiae. Phytochemistry 63: 569–575. 

Predieri S, Rapparini F. 2007. Terpene emission in tissue culture. Pl. Cell Tiss. Org. Cult. 91: 87–95. 

Quiala E, Barbon R, Jimenez E, DeFeria M, Chavez M, Capote A, Perez N. 2006. Biomass production of 

Cymbopogon citrates (D.C.) Stapf. A medicinal plant, in temporary immersion system. In Vitro Cell. Dev. 

Biol. Plant 42: 298–300. 

Rajesh D, Stenzel R, Howard S. 2003. Perillyl alcohol as a radio/chemo-sensitizer in malignant glioma. J. Biol. 

Chem. 278: 35968–35978. 

Robbins SRJ. 1983. Selected Markets for the Essential Oils of Lemongrass, Citronella and Eucalyptus. Tropical 

Products. Institute Publication, London. 

Sangwan NS, Naqvi AA, Sangwan RS. 2000. A novel chemotype of aromatic grass Cymbopogon. In: Kumar S, 

Kukreja AK, Dwivedi S, Singh AK (Eds.), Proc. Of the National Seminar on Research and Development 

in Aromatic Plants: Current Trends in Biology, Uses, Production and Marketing of Essential Oils, 

pp. 483, 484. J. Med. Pl. Sci. Vol. 22 (Suppl. 1B), CIMAP Publication, Lucknow, India. 

Sangwan RS, Sangwan NS. 2000. Metabolic and molecular analysis of chemotypic diversity in Cymbopogon. 

In: Kumar S, Dwivedi S, Kukreja AK, Sharma JR, Bagchi, GD (Eds.), Cymbopogon: The Aromatic 

Grass: A Monograph, pp. 223–247. CIMAP (CSIR) Publication, Lucknow, India. 

Schijlen EG, Ric de Vos CH, Van Tunen AJ, Bovy AG. 2004. Modification of flavonoid biosynthesis in crop 

plants. Phytochemistry 65: 2631–2648. 

Shanker S, Ajaykumar PV, Sangwan NS, Kumar S, Sangwan RS. 1999. Essential oil gland number and ultrastructure 

during Mentha arvensis leaf ontogeny. Biol. Plant. 42: 379–387. 

Sharkey T, Yeh S. 2001. Isoprene emission from plants. Annual Rev. Pl. Physiol. Pl. Mol. Biol. 52: 407–436. 

Sharma JR, Ram RS. 2000. Genetics and genotype improvement of Cymbopogon species. In: Kumar S, 

Dwivedi S, Kukreja AK, Sharma JR, Bagchi, GD (Eds.), Cymbopogon: The Aromatic Grass: A Monograph, 

pp. 85–128. CIMAP (CSIR) Publication, Lucknow, India. 

Shasany AK, Lal RK, Darokar MP, Patra NK, Garg A, Kumar S, Khanuja SPS. 2000. Phenotypic and RAPD 

diversity among Cymbopogon winterianus Jowitt. Accessions in relation to Cymbopogon nardus Rendle. 

Genet. Resour. Crop. Evol. 47: 553–559. 

Shasany AK, Shukla AK, Khanuja SPS. 2007. Medicinal and aromatic plants. In: Kole C (Ed.), Genome Mapping 

and Molecular Breeding in Plants, Vol. 6—Technical Crops, pp. 175–196. Springer-Verlag, Berlin.


Shen T, Wan W, Yuan H. 2007. Secondary metabolites from Cymbopogon opobalsamum and their antiproliferative 

effect on human prostrate cancer cells. Phytochemistry 68: 1331–1337. 

Sobti SN, Verma V, Rao BL. 1982. Scope for development of new cultivars of Cymbopogon as a source of 

terpene chemicals. In: Atal CK, Kapur BM (Eds.), Cultivation and Utilization of Aromatic Plants, 

pp. 302–307. Regional Research Laboratory (CSIR) Jammu, India. 

Soenarko S. 1977. The genus Cymbopogon Sprengel (Gramineae). Reinwardtia 9: 225–375. 

Sreenath HL, Jagadishchandra KS. 1980. Callus induction and growth in two varieties of Cymbopogon nardus 

(L) Rendle. Curr. Sci. 49: 437, 438. 

Sreenath HL, Jagadishchandra KS. 1989. Somatic embryogenesis and plant regeneration from inflorescence 

culture of Java citronella (Cymbopogon winterianus Jowitt). Ann Bot. 64: 211–215. 

Sreenath HL, Jagadishchandra KS. 1991. Cymbopogon Spreng (Aromatic Grasses): In vitro culture, regeneration 

and the production of essential oils. In: Bajaj YPS (Ed.), Biotechnology in Agriculture and Forestry, 

Vol. 15 Medicinal and aromatic plants III, pp. 211–236. Springer-Verlag, Berlin, Heidelberg. 

Stapf O. 1906. The oil grasses of India and Ceylon. Kew Bull. 8: 297–463. 

Tapia A, Georgirev M, Bley T. 2007. Free radical scavengers from Cymbopogon citrates (D.C.) Stapf. Plants 

cultivated in bioreactor of the temporary immersion principle. Z. Naturforsch. Sect. C J Biosci. 62: 

447–457. 

Thapa RK, Bradu BL, Vashit VN, Atal CK. 1971. Screening of Cymbopogon species for useful constituents. 

Flavour India 2: 49–51. 

Tholl D, Boland W, Hansel A, Loreto F, Rose USR. 2006. Practical approaches to plant volatile analysis. The 

Plant J. 45: 540–560. 

Tisserat B, Vaughn SF. 2008. Growth, morphogenesis and essential oil production in Mentha spicata L. plantlets 

in vitro. In Vitro Cell. Dev. Biol.-Plant 44: 40–50. 

Trapp SC, Croteau R. 2001. Genomic organization of plant terpene synthases and molecular evolutionary 

implications. Genetics 158: 811–832. 

Tripathy SK, Kole C, Lenke PC. 2007. Isolation of some useful mutants in citronella. Orisa J. Hort. 35: 

100–102. 

Tyo ET, Alper HS, Stephanopoulos G. 2007. Expanding the metabolic engineering toolbox: more option to 

engineer cells. Trends Biotechnol. 25: 132–137. 

Vasil IK. 2005. The story of transgenic cereals: The challenge, the debate and the solution—A historical perspective. 

In Vitro Cell. Dev. Biol.- Plant 41: 577–583. 

Verpoorte R, Alfermann AW. 2000. Metabolic Engineering of Plant Secondary Metabolism. Kluwer, 

Dordrecht, Netherlands. 

Verpoorte R, Memelink J. 2002. Engineering secondary metabolite production in plants. Curr. Opin. Biotechnol. 

13: 181–187. 

Verpoorte R, van der Heijden R, Memelink J. 2000. Engineering the plant cell factory for secondary metabolite 

production. Transgenic Res. 9: 323–343. 

Wallaart TE, Bouwmeester HJ, Hille J, Poppinga L, Maijers NCA. 2001. Amorpha-4,11-diene synthase: 

Cloning and functional expression of a key enzyme in the biosynthetic pathway of the novel antimalarial 

drug artemisinin. Planta 212: 460–465. 

Wannissorn B, Jarikasem S, Siriwangchai T, Thubthimthed S. 2005. Antibacterial properties of essential oils 

from Thai medicinal plants. Fitoterapia 76: 233–236. 

Williams A, Barry B. 2004. Penetration enhancers. Adv. Drug Delivery Res. 56: 603–618. 

Xu Y, Crouch JH. 2008. Marker-assisted selection in plant breeding: From publication to practice. Crop Sci. 

48: 391–407. 

Yadav U, Mathur AK, Sangwan NS. 2000. In vitro calli-clone regeneration to enhance qualitative variability 

in essential oil of a wild Cymbopogon species. In: Kumar S, Kukreja AK, Dwivedi S, Singh AK 

(Eds.), Proc. of the National Seminar on Research and Development in Aromatic Plants: Current Trends 

in Biology, Uses, Production and Marketing of Essential Oils, pp. 485–487. J. Med. Pl. Sci. Vol. 22 

(Suppl. 1B), CIMAP Publication, Lucknow, India. 

Yonekura-Sakakibara K, Saito K. 2006. Genetically modified plants for the promotion of human health. 

Biotechnol. Lett. 28: 1983–1991. 

Zheng Z, Zhou S, Zhang J, Qing GJ, Xu GZ, Guilin X. 2007. Study on the in vitro culture of African lemongrass. 

Acta Agric. Shanghai 23: 61–64. 

Zutchi NL. 1982. Essential oils—isolates and semi-synthetics. In: Atal CK, Kapur BM (Eds.), Cultivation and 

Utilization of Aromatic Plants, pp. 38, 39. Regional Research Laboratory (CSIR), Jammu Publication.

5 

contents 

The Trade in Commercially 

Important Cymbopogon Oils 

Rakesh Tiwari 

5.1 Introduction .......................................................................................................................... 151 

5.2 Citronella Oil ........................................................................................................................ 151 

5.2.1 World Market, Demand, and Production .................................................................. 152 

5.2.2 World Demand .......................................................................................................... 153 

5.3 Lemongrass Oil .................................................................................................................... 153 

5.3.1 World Production and Demand ................................................................................ 159 

5.3.2 Production ................................................................................................................. 159 

5.4 Palmarosa Oil ....................................................................................................................... 160 

5.4.1 Production ................................................................................................................. 163 

References ...................................................................................................................................... 165 


Among the various species of cymbopogons numbering approximately 120, only four are of 

commercial importance, namely, Cymbopogon winterianus, C. nardus (citronella), C. flexuosus 

(lemongrass), and C. martinii var. motia (palmarosa). Essential oils extracted from mainly leaves 

and aboveground parts of these plants are valued commercially and traded globally (Anonymous 

1986). Accurate production, trade, and export and import figures from third world countries, and 

even some Western countries, are obscure (Lawrence 1985, 1986, 1993). It has been mentioned 

in some old references that reliable trade data are available for oils produced in the United States 

only (Simon 1990). However, export and import data from India are available up to country 

level. The statistics for export and import data for India are collected from available entry points, 

which include seaports, airports, and land routes. The export data, thus, is inclusive of both 

exports and re-exports. 

5.2 cItronella oIl 

Citronella oil is an industrially important essential oil obtained from leaves and stems of C. winterianus 

and C. nardus. The oil is regarded as one of the 20 most important essential oils (Lawrence 

1993) found in the world trade. Citronella oil is an important source of perfumery chemicals such as 

citronellol, citronellal, and geraniol, which are widely used in perfumery, soaps, detergents, industrial 

polishes, cleaning compounds, and other industrial products (Anonymous 1986; Lawless 1995). In the 

trade, citronella oil is classified into two chemotypes: Ceylon-type citronella oil and Java-type citronella 

oils. Ceylon-type citronella oil is extracted from C. nardus Rendle, and Java-type citronella oil 

is obtained from C. winterianus Jowitt (Torres and Tio [2003]). The name C. winterianus was given 

151


to this selected variety to commemorate Winter, an important oil distiller of Ceylon (now Sri Lanka), 

who first cultivated and distilled the Maha Pangeri type of citronella in Ceylon (Chang 2007). 

The main difference between the Ceylon and Java types of oil is the relative proportion of geraniol 

and citronellal. Java-type citronella oil is characterized by a high proportion of geraniol (11%–13%) 

and citronellal (32%–45%), making it an important source of derivatives such as citronellol and 

hydroxycitronellal, which are extensively used in compounding high-grade perfumes. Other major 

constituents of the oil are geranyl acetate (3%–8%) and limonene (1%–4%). The chemistry of the oil 

is discussed in another chapter 2 of this book. 

Ceylon-type citronella oil contains a relatively low proportion of geraniol (18%–20%) and citronellal 

(5%–15%), and is mainly used as such in lower-grade products. Unlike Java-type oil, it is 

rarely used for the extraction of derivatives. The other major constituents of Ceylon-type oil are 

limonene (9%–11%), methyl isoeugenol (7%–11%), and citronellol (6%–8%). 

Citronella oil (both Ceylon and Java types) is also a renowned plant-based insect repellent, and 

has been registered for use in the United States since 1948 as “McKesson’s Oil of Citronella” for 

human application to repel gnats and mosquitoes. The U.S. Environment Protection Agency (EPA) 

considers oil of citronella as a biopesticide with a nontoxic mode of action (Anonymous 1997, 2001, 

2004, 2006, 2007; Trongtokit et al. 2005). It is registered as an insect repellent, feeding depressant, 

and animal repellent. Research also shows that citronella oil has strong antifungal properties and is 

effective in calming barking dogs. 

5.2.1 wo r l d Ma r k e t, de M a n d, a n d Pr o d u C t i o n 

The data on world market size, market price, world production, global area under cultivation, 

number of cultivators engaged, etc., are not easily available due to lack of reliable documentation 

for such items. The problem is further aggravated because of the lack of scientific documentation 

in many of the major producer countries. The current world production of citronella 

oil is estimated at 5000 t, valued at about 20 million USD. The majority of the oil is Java type, 

with Indonesia as the major supplier in commercial quantities (Robbins 1983). Production of 

Ceylon-type oil is restricted to Sri Lanka, where it peaks out to approximately 200 t (Oyen 

and Nguyen 1999). Major producers of citronella oil are China and Indonesia, which account 

for more than 40% of the world production. The oil is also produced in Taiwan, Guatemala, 

Honduras, Brazil, Sri Lanka, India, Argentina, Ecuador, Jamaica, Madagascar, Mexico, and 

South Africa (Lawrence 1985). Citronella oil is used in a variety of products in India. India 

was a net importing country 60 years ago, but currently produces approximately 600 t of the oil 

(Singh et al. 2000). 

The leading exporters of citronella oil are China, Indonesia, Taiwan, Guatemala, Sri Lanka, 

Argentina, and Brazil. Officially, Indonesia is the leading exporter of oil, probably because statistics 

on China’s export volume are not available. European countries such as France and United Kingdom 

play an important role in the world’s export of citronella oil; presumably a significant proportion 

of their import is being re-exported. The same probably is true of Singapore, as this country has a 

considerable role as an entry port in the citronella oil trade. 

Citronella oil has been witnessing demand and price fluctuations due to proliferation of inexpensive 

synthetic isolates in the market (Robbins 1983). Earlier, Java citronella oil was the most 

important source of geraniol and citronellal, but the advent of pinene chemistry and production of 

these isolates in reasonable quantity reduced the demand and reliance for Java-type citronella oil. 

Further, due to its rich citronellal content, oil from Eucalyptus citriodora has become another major 

competitor of citronella oil in the world market (Anonymous 1986). Thus, the overall demand for citronella 

oil has been affected by synthetic isolates produced from turpentine oil and E. citriodora oil. 

These isolates and substitutes are generally cheaper than citronella oil, making them the preferred

The Trade in Commercially Important Cymbopogon Oils 153 

choice when price is the main criterion. However, natural citronella oil and its derivatives are still the 

preferred choice of the perfumery industry, mainly because of its unique olfactory and stable properties, 

which are vital in blending perfumes and compounding industrially important essences. 

The state of Assam leads in the production of citronella oil in India owing to climatic conditions 

suited for the cultivation of the crop. The area under cultivation is around 10,000 hectares (ha). 

Export and import of citronella oil in India are well documented by Ministry of Commerce and 

Industry publications (Anonymous 2003–2007a, 2003–2007b). 

5.2.2 wo r l d de M a n d 

Earlier, there were no official data available on the current world demand for citronella oil. 

International Trade Centre has published data on citronella-oil-importing countries in 1981, which 

was used in predicting possible trends for the market of citronella oil. However, the situation has 

improved significantly since then. 

The United States of America is the world’s largest importer of citronella oil, followed by 

European countries, namely, France, United Kingdom, Germany, and the Netherlands. The European 

countries are the major trading hub for Java-type oil because of the presence and proximity 

of the world-famous perfumery industry, notably in France and Germany. In the Asian region, the 

largest importers of citronella oil are Japan and Hong Kong. Hong Kong does a lot of re-export of 

citronella oil to the Philippines. 

The consolidated export–import data of citronella oil with respect to India is given under 

Table 5.1, and countrywise breakup of exports and imports is reproduced in Tables 5.2 and 5.3. 

5.3 lemongrass oIl 

table 5.1 

consolidated export and Import Figures of citronella 

oil for India 

year 

citronella oil 

exports Imports 

Quantity (t) Value (usd) Quantity (t) Value (usd) 

2007 617.502 7,490,027 270.787 1,669,257 

2006 440.065 5,322,190 189.462 1,013,885 

2005 308.043 2,325,885 115.888 863,690 

2004 100.179 1,418,954 122.765 724,823 

2003 72.200 616,819 42.558 502,509 

2002 33.477 174,241 76.087 574,743 

Source: Monthly Statistics of Foreign Trade of India, Vol. 1 and 2. 

Lemongrass oil is obtained by steam distillation of leaves and flowering tops of C. flexuosus and 

C. citratus. The oil is a commercially important commodity with antifungal properties. The name 

lemongrass is attributed to the lemon-like odor of the essential oil, which is due to high citral 

content. Two chemotypes of lemongrass oil are well recognized in the trade, namely, East Indian 

and West Indian lemongrass oil. East Indian lemongrass, obtained from C. flexuosus, is also called 

Cochin grass or Malabar grass. It is native to Cambodia, India, Sri Lanka, Burma, and Thailand.


table 5.2 

countrywise Import of citronella oil by India 

2002 2003 2004 2005 2006 2007 

Qty Value Qty Value Qty Value Qty Value Qty Value Qty Value 

country (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) 

Australia — — — — 20 395 660 9,759 110 4,556 252 52,209 

Austria 125 3,191 — — — — — — — — 115 4,416 

Brazil — — 8,335 50,303 13 218 6,780 29,218 2 53 8,482 62,888 

Canada 1,000 3,704 — — 30 341 — — — — — — 

China 7,302 38,388 2,340 18,740 79,118 335,885 45,206 231,737 117,649 445,273 193,650 881,181 

France 1,473 27,250 6,523 64,726 1,315 63,728 4,482 97,189 3,646 55,110 678 27,290 

Germany 2,122 17,041 2,650 29,072 820 27,298 843 29,634 2,633 48,534 6,599 71,771 

Hong Kong — — — — — — — — 520 5,606 — — 

Hungary — — 25 1,205 — — — — — — — — 

Indonesia 2,090 67,914 105 2,636 1,650 6,120 20,540 83,200 27,520 103,900 1,650 20,409 

Ireland — — — — — — — 646 30 180 

Israel 165 1,691 20 258 5,352 22,455 2,118 21,682 120 3,887 

Italy 870 6,374 13 579 205 8,530 380 13,612 1,027 30,818 1,151 33,867 

Japan 596 16,888 111 507 — — — — — — 2 12 

Malaysia — — — — 10 75 — — 4 252 — — 

Nepal 24,498 33,624 4,000 20,592 17,200 47,655 7,730 87,136 2,400 12,121 1,445 15,493


Netherlands 40 1,192 — — 1 48 25 504 — — 39 1,297 

Paraguay — — — — 2,090 21,280 — — 570 5,504 2,000 15,891 

Poland 815 1,189 138 1,678 713 4,561 40 2,204 2 374 

Singapore 2,291 10,510 8,865 120,551 2,300 14,072 175 1,343 4,307 35,610 795 24,131 

Slovenia — — — — 75 5087 — — — — — — 

Spain 545 1,690 1,506 25,302 1,100 31,386 4,944 21,130 11,401 46,841 21,189 98,421 

Sri Lanka — — — — 280 4,164 — — — — — — 

Swaziland — — — — — — — — — — 241 3,458 

Switzerland 840 7,840 — — 1,280 3,044 25 1,512 480 7,226 386 8,950 

Tanzania — — — — — — — — 200 13,087 1,249 77,109 

Thailand 42 1137 — — — — — — — — 95 3,171 

UAE — — — — 202 1,532 52 529 2 23 — — 

U.K. 2,776 39,089 1,247 32,498 1,066 35,243 1,789 93,782 1,496 36,255 3,931 52,479 

U.S. 25,712 275,506 9,500 130,291 7,201 84,528 15,826 123,247 13,625 153,526 24,716 196,726 

Uruguay — — — — 1,199 2,835 — — — — — — 

Unspecified — — — — 100 7,226 — — — — — — 

Vietnam 3,600 21,714 5,040 4,060 — — 3,600 13,269 1,800 7,206 2,000 13,827 

Total 76,087 574,743 42,558 502,509 122,765 724,823 115,888 863,690 189,462 1,013,885 270,787 1,669,257 

Source: Monthly Statistics of Foreign Trade of India, Vol. 1 and 2.


table 5.3 

countrywise export of citronella oil by India 

2002 2003 2004 2005 2006 2007 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

country 

Afghanistan — — — — — — — — — — 100 456 

Angola — — — — — — — — — — 2,000 42,912 

Australia 67 255 — — 300 1,507 951 9,193 630 11,054 1,840 24,376 

Austria 16 5,033 16 905 — — 700 1,740 — — 300 2,066 

Bahrain — — — — — — — — 178 15,844 1,450 55,539 

Bangladesh 2,500 5,574 — — — — 1,800 4,108 4,500 7,777 5,410 10,029 

Belgium — — 50 2,605 80 551 180 1,328 — — — — 

Bulgaria — — — — 20 1,065 1,530 15,913 — — — — 

Cambodia — — — — — — — — 2,080 12,737 25 5,978 

Canada 40 1,904 9,021 24,539 3,261 26,597 189 3,656 231 2,261 230 10,001 

Chile — — — — 700 5,753 

China — — 14,450 95,189 — — 11 147 45,200 430,406 76,874 1,088,379 

Chinese Taipei — — 107 11,569 — — — — — — — — 

Colombia — — — — — — — — 360 5,819 117 3,352 

Congo P REP — — — — 5,600 26,342 — — — — 26,773 79,226 

Costa Rica — — — — — — — — 40 867 — — 

Czech Republic — — — — 11 1,153 — — 1,005 17,847 

Denmark 720 3,841 — — 30 827 50 1,409 — — — — 

Djibouti — — — — — — — — 400 12,101 — — 

Egypt — — — — 45 998 75 1,458 70 1,342 — — 

Ethiopia — — — — 3,060 7,268 1,620 8,533 — — — — 

Fiji — — — — — — — — — — 17 746 

Finland — — — — — — — — — — 5,860 100,293 

France 1,407 22,365 1,257 22,476 1,180 13,597 8,225 152,677 5,376 117,235 2,908 39,223 

Gambia — — — — — — 56 3068 — — — — 

Germany 35 2,395 3,280 46,450 13,330 84,528 500 36,404 4,560 59,299 11,235 316,242 

Ghana — — — — — — 16,850 39,311 — — 11,600 108,785 

Greece — — — — 600 3,523 — — — — — —


Guyana — — — — — — — — — — 150 2,023 

Hong Kong — — — — 145 4,066 7,500 251,457 40 1,499 28,895 347,037 

Hungary — — 100 795 — — — — 26 1,963 565 12,063 

Iceland — — — — — — — — — — 31 2,230 

Indonesia — — 1,000 10,937 10 358 — — 190 2,960 

Iran — — — — 50 1,163 50 1,317 — — — — 

Ireland — — — — — — 140 2,160 30 254 180 1,343 

Israel — — 1,000 5,863 20 213 — — — — 685 12,648 

Italy — — 1,854 26,273 2 177 14,543 98,830 30 1,587 24 772 

Jamaica — — — — — — — — — — 150 2,159 

Japan — — — — 5,102 438,600 4,320 36,859 4,430 64,159 4,071 124,168 

Jordan — — — — — — — — — — 50 652 

Kenya — — — — 15,40 76,777 34,783 199,318 31,819 263,200 40,750 337,873 

Korea DP RP — — — — — — 1,000 6,952 — — 228 4,907 

Korea RP — — — — 1,500 7,599 — — 1,566 23,138 215 6,015 

Kuwait — — 20 1,429 — — 298 9,933 299 10,420 118 11,164 

Latvia — — — — — — — — 333 5,169 101 4,836 

Malaysia 1,496 17,917 100 245 1,324 7,629 4,082 13,539 265 4,834 4,039 24,910 

Maldives — 40 1,192 430 4,285 100 511 — — — — 

Mauritius — 85 1,642 65 1,107 852 6,081 3,540 15,440 110 3,701 

Mexico 501 6,149 — — — — — — 50 375 — — 

Mozambique — — — — — — — — 720 1686 170 3503 

Myanmar 8,000 20,123 1,100 4,126 5,000 54,727 2,000 30,853 — — — — 

Nepal 359 5,612 10 61 1,061 6,672 4,421 30,561 5,474 36,963 

Netherlands 804 7,843 4,000 33,633 865 21,158 169 13,812 1,100 14,873 10,141 171,511 

New Caledonia — — — — — — — — — — 100 143 

New Zealand — — 9 395 — — 2 96 670 971 150 5,751 

Nigeria — — 24 570 4,182 52,693 — — 105,891 288,324 90,118 347,096 

Oman 2,000 2,953 — — 65 1,058 — — 200 1,489 55 1,247 

Pakistan — — — — 25 1,955 — — — — 145 7,607 

Panama Republic — — — — 42 3,034 171 9,072 — — — — 

Paraguay — — — — — — — — — — 4,000 86,736 

Peru — — — — — — 1,000 26,056 — — — — 

Philippines — — — — — — — — — — — — 




countrywise export of citronella oil by India 

2002 2003 2004 2005 2006 2007 


country 

(kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) 

Poland — — — — — — — — 445 7,269 70 207 

Reunion — — — — — — — — — — — — 

Romania — — — — — — 110 7,843 — — — — 

Russia — — — — — — — — 1,100 5,714 1,400 13,883 

Rwanda — — — — — — 500 1,381 — — — — 

Saudi Arabia — — — — 1,925 6,036 1,170 24,321 2,605 66,550 1,287 45,409 

Singapore 6,250 13,724 1,408 24,902 3,358 30,928 1,3111 88,392 710 21,360 30,294 292,650 

South Africa 12 171 600 3,761 460 10,357 1,870 30,024 2,500 50,539 2,462 50,139 

Spain 600 17,784 16,346 112,975 193 2,443 1,654 118,038 4,570 60,387 9,400 128,492 

Sri Lanka 450 5,575 6,540 39,485 65 2,514 2,835 14,553 2,370 8,777 86 4,048 

Sudan — — — — — — 11,500 15,716 300 3,708 10 602 

Switzerland — — — — 190 980 1,252 15,471 750 63,819 2,000 49,887 

Syria — — — — — — — — — — 100 2,482 

Taiwan — — — — 120 3,597 151 4,028 11 381 6 778 

Tanzania — — — — 34,290 186,623 84,913 348,669 59,200 366,188 35,530 171,104 

Thailand 1,500 2,783 500 1,132 — — — — 2,700 37,477 43 5,749 

Tunisia — — — — — — — — — — 934 107,816 

Turkey — — — — — — — — 25 245 325 8,644 

Uganda 526 1,498 — — 460 2,500 600 5,215 20 419 1,080 12,586 

UAE 4,960 13,923 4,591 20,912 6,125 39,496 4,003 44,813 9,716 996,468 6,206 137,707 

U.K. 458 25,668 500 23,242 26,104 225,236 26,562 444,360 64,912 756,278 

U.S. 1,593 22,431 3,885 91,539 3,790 257,425 46,140 368,914 98,430 1,735,440 121,872 2,231,351 

Yemen — — — — — — — — 8,795 43,064 1,020 4,929 

Zambia — — — — — — 3,160 7,339 — — — — 

Unspecified — — — — — — 4,000 8,288 — — — — 

Total 33,477 174,241 72,200 616,819 100,179 1,418,954 308,043 2,325,885 440,065 5,322,190 617,502 7,490,027 

Source: Monthly Statistics of Foreign Trade of India, Vol. 1 and 2.


West Indian lemongrass, obtained from C. citratus, is assumed to be native to Malaysia. While both 

can be used interchangeably, C. citratus is more suited for cooking. In India, C. citratus is used 

both as a medicinal herb and in perfumes. The main difference between these two types of oil is 

the relative percentage of citral. East Indian lemongrass oil is higher in citral content, which ranges 

up to 90%. West Indian lemongrass oil has lower citral content and lower solubility in alcohol. The 

lower solubility is attributed to the presence of myrcene, which polymerizes on exposure to air and 

light. In the trade, West Indian oil is considered inferior to East Indian oil and has meager trade. The 

name West Indian lemongrass oil is a misnomer in the sense that this grass is not indigenous to West 

Indies and, currently, the production of lemongrass in West Indies is very low (Husain 1993). 

The lemongrass oil finds widespread use in soap, perfumery, cosmetics, and the beverages industry. 

Additionally, it is an important natural source of citral, which is an important starting material 

for the synthesis of beta ionone. Beta ionone is further used for synthesis of a number of aroma 

chemicals widely used in perfumery and cosmetics. Beta ionone is also used to produce vitamin A. 

Due to its distinct lemony flavor, the herb itself finds use in imparting citrus flavor in fresh, chopped 

and sliced, or dried and powdered forms. Lemongrass is commonly used in teas, soups, and curries. 

In India, the record of medicinal use of lemongrass oil dates back to more than 2000 years, though 

its distillation started only in 1890. 

5.3.1 wo r l d Pr o d u C t i o n a n d de M a n d 

During the early 1950s, India produced over 1800 t/annum of lemongrass oil and held monopoly 

both in production and world trade. This has changed, as Guatemala, China, Mexico, Bangladesh, 

etc., have developed large-scale cultivation of lemongrass. 

Currently, the world production of oil of lemongrass ranges between 800 and 1300 t/annum 

(Singh et al. 2000). However, another 600 t of a substitute oil, that is, Litsea cubeba (rich in citral), 

is exported by China, which limits the scope for any faster growth in export trade of lemongrass oil 

(Lawrence 1985). Synthetic citral available at a relatively lower rate competes with lemongrass 

oil and natural citral in the market. 

5.3.2 Pr o d u C t i o n 

India is a major producer of the oil, and about 80% of the produce is exported, mainly to West 

Europe, United States, and Japan. The situation changed during the Second World War because of 

problems of production and supply logistics. Consequently, Guatemala, Haiti, Madagascar, Zaire, 

Cambodia, Vietnam, and Laos started producing lemongrass oil to meet the demand, and continue 

to do so. Guatemala, China, Mexico, Bangladesh, etc., have developed its cultivation over large 

areas. India has moved to systematic cultivation of lemongrass; earlier, it was mainly collected from 

wild forests. East Indian lemongrass oil is preferred due to its high citral content. Though exact 

information on production and trade from the producing countries is not available, the current world 

production of the oil is estimated at 1300 t/annum, with India contributing to the tune of 350 t. The 

consolidated export–import data of lemongrass oil with respect to India is given in Table 5.4, and 

the countrywise breakup of the export and import figures is presented in Tables 5.5 and 5.6. 

In India, the crop grows in an area of about 3000 ha, largely in the states of Kerala, Karnataka, 

Tamil Nadu, Maharashtra Uttar Pradesh and Assam. Supply of cheaper citral by China produced 

from alternative sources results in periodic fluctuation in demand for lemongrass oil. However, in 

general, the global demand for the oil is robust. 

Currently, other major lemongrass-oil-producing countries are Brazil, China, Guatemala, Haiti, 

Nepal, Russia, and Sri Lanka.


table 5.5 

countrywise Import of lemongrass by India 

country 

Qty 

(kg) 

5.4 Palmarosa oIl 

2002 2003 2004 2005 2006 2007 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Palmarosa oil of commerce is obtained by steam distillation of ground, freshly harvested or partially 

dried flowering shoot biomass leaves and stems of C. martinii var. motia. The oil is valued 

for its aroma chemical geraniol (75%–90%), which is separated through fractional distillation of 

the essential oil. Geraniol is widely used in flavor, fragrance, and pharmaceutical industries. The 

oil is extensively used as perfumery raw material in soaps, floral rose-like perfumes, cosmetics 

preparations, and in the manufacture of mosquito repellent products. It is used for flavoring tobacco 

products, foods, and nonalcoholic beverages. In medicine, the volatile oil is used as a remedy for 

lumbago, stiff joints, skin diseases, and for bilious complaints. Another variety, C. martinii var. 

sofia, which has lower geraniol content (


table 5.6 

countrywise export of lemongrass oil by India 

2002 2003 2004 2005 2006 2007 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

country 

Australia 5,636 45,685 1,980 21,291 1,760 23,673 1,600 16,055 3,520 36,946 5,040 60,926 

Austria 20 336 — — — — — — — — — — 

Belgium — — — — — — — — 540 5,235 1,080 15,118 

Bosnia — — — — 22 1,162 — — — — — — 

Brazil — — — — — — — — 600 6,850 400 4,531 

Canada 400 4,031 415 4,323 400 3,986 35 2,149 800 4,935 600 6,514 

China — — 10 191 — — — — — — 95 1,464 

Denmark — — — — — — 420 9,623 100 679 — — 

Ecuador — — — — — — 2 34 10 161 — — 

Egypt — — 20 506 — — — — 100 796 100 791 

French South and — — — — — — — — — — 1 9 

Antarctic Territories 

Fiji — — — — — — 30 126 — — — — 

France 6,000 63,216 4,709 49,137 540 5,962 — — 1,982 20,855 5,640 70,816 

Germany 4,400 46,962 7,733 91,140 6,360 62,518 3,206 30,524 4,820 50,520 5,250 58,583 

Ghana — — 25 218 — — — — — — — — 

Greece 750 3,400 — — — — — — — — 

Guatemala — — — — — — — — 1,080 11,620 1,260 14,460 

Hong Kong — — 10 105 — — — — — — — — 

Indonesia — — 25 325 — — — — — — — — 

Israel 20 330 45 655 145 2031 20 185 940 8,220 — — 

Italy — — 56 4,243 — — — — — — 410 4,667 

Japan 1,620 17,380 — — 740 9,047 540 5,033 540 4,740 390 4,338 

Kenya 150 2,299 1,135 7,262 — — — — — — 100 1,360 

Korea RP 30 471 6 58 — — 1,000 2,110 — — 200 3,025 

Maldives — — — — — — — — 43 493 — — 




countrywise export of lemongrass oil by India 

2002 2003 2004 2005 2006 2007 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

country 

Mauritius — — — — 10 150 — — 50 375 — — 

Mexico — — — — 360 3,145 — — — — — — 

Myanmar — — — — 1,000 30,143 30 346 — — — — 

Nepal — — — — — — 100 663 — — — — 

Netherlands 180 1,942 — — 5,000 43,671 2,000 16,711 — — 

New Zealand — — — — — — — — — — 100 1,043 

Oman — — — — 210 1,406 — — — — — — 

Philippines — — — — — — — — 150 347 — — 

Singapore 1,200 13,542 1,880 20,873 367 4,741 1,960 17,871 3,965 35,172 2,760 29,741 

Slovenia 80 848 — — — — — — — — — — 

South Africa — — — — 50 632 — — — — 

Spain 900 8,890 — — 1,080 10,511 — — 1,190 13,089 — — 

Sri Lanka 1,140 10,828 210 2,726 20 176 1,315 10,929 584 6,411 975 11,325 

Surinam — — — — 420 5,135 — — — — — — 

Switzerland — — 3 114 — — — — 1,080 10,561 6,888 73,801 

Taiwan — — — — 30 522 50 485 — — 2,180 24,565 

Thailand 20 209 2,150 23,067 500 5,491 625 4,891 220 1,971 601 5,232 

Tanzania 50 466 — — — — — — 

U.K. 13,575 135,961 12,670 128,514 7,340 70,775 6,800 55,703 18,760 171,513 12,056 135,112 

U.S. 10,837 103,136 12,125 118,594 5,025 48,911 13,400 117,976 24,419 232,949 25,148 279,271 

Unspecified — — — — 700 122 — — — — — — 

Vietnam — — — — — — — — — — 100 438 

Yemen — — — — — — — — — — 66 1,392 

Total 46,778 457,523 45,387 475,284 27,079 290,072 36,183 319,004 67,493 641,147 71,440 808,521 

Source: Anonymous 2003–2007a.


traditional medicine and household uses. The essential oil has a scent similar to that of rose oil, and 

hence the name palmarosa. 

5.4.1 Pr o d u C t i o n 

Historically, the first attempt at its cultivation dates back to 1924 in West Punjab, which now is in 

Pakistan. Later, its cultivation in India was started in the early 1950s in Dehra Dun (Uttarakhand). 

Currently, the crop is cultivated in several states of India, namely, Uttar Pradesh, Uttarakhand, 

Assam, Andhra Pradesh, and Karnataka. The grass has been introduced to the Central American 

countries of Guatemala, Honduras, Indonesia, and Brazil (Husain 1993). 

The current Indian production is around 100 t of oil per year, with consumption figures of 

40–60 t. India enjoyed a virtual monopoly in palmarosa oil production until the 1990s. Indian palmarosa 

oil was rated as premium quality oil with 80%–90% geraniol content. Brazil was the second 

largest producer of the oil (Lawrence 1985). Later, Brazil, Indonesia, Honduras, and Guatemala 

started producing and supplying better quality oil in the world market. With the appearance of 

synthetic geraniol, the world market witnessed a weakening in demand for natural palmarosa oil. 

The consolidated export–import data of palmarosa oil for India is given in Table 5.7, and countrywise 

breakup of the export and import is presented in Tables 5.8 and 5.9. The United States is the 

major importer of the oil, followed by Europe (France, Germany, the Netherlands, and the United 

Kingdom) and Australia. 

table 5.8 

country-wise breakup of the Import Figures of Palmarosa oil for India 

country 

table 5.7 

consolidated export and Import Figures of Palmarosa 

oil for India 

year 

Qty 

(kg) 

2003 2004 2005 2006 

Value 

(usd) 

Qty 

(kg) 

Palmarosa oil 

exports Imports 

Quantity (t) Value (usd) Quantity (t) Value (usd) 

2007 20.684 365,323 0 0 

2006 17.883 212,466 0.56 24,852 

2005 7.257 79,313 0.027 226 

2004 14.795 183,779 0.11 7,949 

2003 22.828 318,365 0.5 24,405 

2002 11.620 166,449 — — 

Source: Anonymous 2003–2007a and b. 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Qty 

(kg) 

Value 

(usd) 

Germany 500 24,406 — — — — 200 11,116 

Indonesia — — — — — — 360 13,736 

UAE — — — — 3 118 — — 

U.K. — — 110 7,950 — — — — 

U.S. — — — — 24 108 — — 

Total 500 24,406 110 7,950 27 226 560 24,852


table 5.9 

countrywise export of Palmarosa oil by India 

2002 2003 2004 2005 2006 2007 


country (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) (kg) (usd) 

Argentina — — — — 10 118 — — — — 20 351 

Australia — — 410 5,387 161 2,981 — — — — 25 386 

Bahrain — — — — — — — — — — 25 1,469 

Canada 1,000 14,358 — — — — — — — — 10 467 

France 3,860 55,877 2,338 33,458 2,080 22,070 540 5,838 1,105 16,394 3,740 67,284 

Germany 360 4,916 5,220 70,770 — — 485 5,062 1,880 24,615 2,365 37,042 

Hong Kong — — — — — — 100 1,798 300 4,963 145 8,408 

Ireland — — 360 4,694 — — — — — — 360 6,472 

Japan — — — — — — 1,080 10,754 20 506 4 107 

Mexico — — — — 50 589 — — — — — — 

Netherlands — — 1,800 25,422 4,680 63,232 3,060 32,600 2,880 44,090 2,700 54,114 

New Zealand 130 3,542 — — — — — — — — — — 

Singapore — — 260 3,372 240 3,419 — — — — 200 2,738 

South Africa — — — — — — 10 126 — — — — 

Spain 900 11,002 1,260 17,919 1,580 19,526 1,080 12,708 5,287 33,534 680 12,435 

Switzerland 540 8,451 720 12,992 — — 720 9,140 1,410 26,128 — — 

Taiwan — — — — 20 271 — — — — — — 

Tanzania — — — — — — — — — — 30 319 

Thailand — — — — — — 2 35 200 4,296 — — 

UAE — — — — 24 235 — — — — 500 9,191 

U.S. 4,830 68,303 10,460 144,351 5,950 71,338 180 1,252 4,801 57,940 9,880 164,540 

Total 11,620 166,449 22,828 318,365 14,795 183,779 7,257 79,313 17,883 212,466 20,684 365,323


reFerences 

Anonymous. 1997. U.S. Environmental Protection Agency Fact Sheet. 1997. Prevention, Pesticides and Toxic 

Substances (7508W), Re registration Eligibility Decision Sheet EPA-738-F-97-002 (February 1997). 

Anonymous. 1986. Essential oils and oleoresins: A study of selected producers and major markets. Int. Trade 

Centre, UNCTAD/GATT, Geneva. 

Anonymous. 2001. WHO International Programme on Chemical Safety: Guidance document for the use of 

chemical specific adjustment factors (CSAFs) for interspecies differences and human variability in dose 

concentration response assessment. 76 pp. World Health Organization, Geneva. 

Anonymous. 2007. Citronella (Oil of Citronella (021901) Fact Sheet), U.S. Environmental Protection Agency. 

Issued 11/99; Updated October 22, 2007. 

Anonymous. 2003–2007a. Monthly Statistics of Foreign Trade of India. Vol. I, Exports and Re-Exports March, 

DG CI&S, Ministry of Commerce and Industry, Govt. of India, Kolkata. 

Anonymous. 2003–2007b. Monthly Statistics of Foreign Trade of India. Vol. II, Imports, Directorate General of 

Commercial Intelligence and Statistics, Ministry of Commerce and Industry, Govt. of India, Kolkata. 

Anonymous. 2004. Re-evaluation of citronella oil and related active compounds for use as personal insect 

repellants, Proposed Acceptability for Continuing Registration PACR 3004–36, September 17, 2004, 

Pest Management Regulatory Agency, Ontario, Canada. 

Anonymous. 2006. Report of an independent science panel on citronella oil used as an insect repellent. 

March 16, 2006, Canada. 

Anonymous 2008. Essential oil dictionary, detailed reference guide and herbal encyclopaedia. http://www. 

deancoleman.com/essentialref.htm. 

Chang Yu S. 2007. Eight MAP species from Malaysia for ICS. Forest Research Institute Malaysia, Workshop 

on NFP, 28029 May 2007, Nanchang, China. 

Husain A. 1993. Essential Oil Plants and Their Cultivation. Central Institute of Medicinal and Aromatic Plants, 

Lucknow, India. 

Lawless J. 1995. The Illustrated Encyclopedia of Essential Oils: Complete Guide to the Use of Oils in Aromatherapy 

and Herbalism, Thorson, U.K. 

Lawrence B. M. 1985. A review of the world production of essential oils (1984). Perfum Flav. 10: 1–16. 

Lawrence B. M. 1986. Essential oil production: A discussion of influencing factors. In T. H. Parliament and 

R. Croteau (Eds.). Biogeneration of Aromas, pp. 363–369. ACS Symposium Series 317 Amer. Chem. 

Soc., Washington, DC. 

Lawrence B. M. 1993. A planning scheme to evaluate new aromatic plants for the flavour and fragrance industries, 

pp. 620–627. In J. Janick and J. E. Simon (Eds.). New Crops, Wiley, New York. 

Oyen L. P. A. and Nguyen X. D. 1999. Plant Resources of South East Asia No. 19: Essential Oil Plants. 

Backhuys Publishers, Leiden. 

Robbins S. R. J. 1983. Selected markets for essential oil of lemongrass, citronella and eucalyptus. Tropical 

Products Research Institute 6171, London. 

Rosalinda C. Torres and Barbara D. J. Tio. Citronella oil industry: challenges and breakthroughs. 

Simon J. E. 1990. Essential oils and culinary herbs. Advances in New Crops, pp. 472–483. In J. Janick and 

J. E. Simon (Eds.). Timber Press, Portland. 

Singh A. K., Gauniyal A. K., and Virmani O. P. 2000. Essential oil of important Cymbopogons: Production 

and trade. In Kumar S. et al. (Eds.). Cymbopogon: The Aromatic Grass Monograph. Central Institute of 

Medicinal and Aromatic Plants, Lucknow, India. 

Smith R. L., Cohen S. M., Doull J., Feron V. Y., Goodman J. I., Marnett L. J., Portoghese P. S., Waddel W. J., 

Wagner B. M., Hall R. L., Higley N. A., Lucas-Gavin C., and Adams T. B. 2005. A procedure evaluation of 

natural flavour complexes used as ingredients in food: Essential oils. Food Chem. Toxicol. 43: 345–363. 

Torres R. C. and Tio B. D. 2001. Citronella (Cymbopogon winterianus) oil industry challenge. 

Trongtokit Y., Rongsriyam Y., Komalamisra N., and Apiwathnasorn C. 2005. Comparative repellency of 38 

essential oils against mosquito bites. Phytother Res. 19(4): 303–309.

6 

contents 


In Vitro Antimicrobial and 

Antioxidant Activities of 

Some Cymbopogon Species 


6.1 Introduction .......................................................................................................................... 167 

6.2 Factors Affecting Antimicrobial Activity of Essential Oils ................................................. 168 

6.2.1 Solubilizing Agents ................................................................................................... 168 

6.2.2 Type of Organism ..................................................................................................... 169 

6.2.2.1 Gram-Positive Bacteria .............................................................................. 169 

6.2.2.2 Gram-Negative Bacteria ............................................................................ 169 

6.2.2.3 Mould and Yeast ........................................................................................ 169 

6.2.3 The Correlation between Oil Components and Activity .......................................... 169 

6.2.4 Methods Commonly Used for Antimicrobial Assessment of Essential Oil ............. 170 

6.2.4.1 The Serial Broth Dilution Method ............................................................. 170 

6.2.4.2 The Agar Diffusion Method ...................................................................... 170 

6.2.4.3 Vapor Contact Assay .................................................................................. 170 

6.3 In Vitro Antioxidant Activity of Some Cymbopogon Species and Their Major 

Components .......................................................................................................................... 178 

6.3.1 Factors Affecting Antioxidant Activity .................................................................... 178 

6.3.1.1 Choice of Oxidizable Substrate and End-Product Evaluation ................... 178 

6.3.1.2 Media ......................................................................................................... 178 

6.3.1.3 Oxidation Conditions ................................................................................. 179 

6.3.1.4 Methods Commonly Used for Testing Antioxidant Activity of 

Essential Oils ............................................................................................. 180 

6.4 Summary .............................................................................................................................. 180 

References ...................................................................................................................................... 181 

Essential oils have been widely used in antimicrobial, antiviral, antiparasitical, insecticidal, medical, 

and cosmetic applications (Bakkali et al. 2008). Cymbopogon species are well known as a source 

of commercially valuable compounds, such as geraniol, geranyl acetate, citral (neral and geranial), 

citronellal, piperitone, eugenol, etc. (Shahi and Tava 1993). Bioactivity of Cymbopogon species 

such as lemongrass (C. citratus), Indian lemongrass (C. flexuosus), Indian palmarosa (C. martinii), 

Java citronella (C. winterianus), and Ceylon citronella (C. nardus) has been reported. Essential oils 

from Cymbopogon species and their components are known for their antimicrobial (de Billerbeck 

et al. 2001; Pattnaik et al. 1995a; Pattnaik et al. 1995b) and antioxidant activities (Hierro et al. 2004; 

Ruberto and Baratta 2000; Lertsatittanakorn et al. 2006). Bioactivity of the same essential oils may 

be markedly different when using different strains of the same microorganism and different sources 

167


of essential oils. According to Oussalah et al. (2006), the major constituents of lemongrass oil 

are citral (77%) and limonene (8.5%); Indian lemongrass has citral (77%); palmarosa has geraniol 

(80%) and gerany1 acetate (8.6%) as main constituents; Java citronella oil contains citronellal (34%), 

geraniol (21.5%), and citronellol (11.5%) as major components; and Ceylon citronella oil contains 

geraniol (19.1%), limonene (9.9%), and camphene (9.0%). Since the oils are poorly soluble in water, 

many factors affect the results of their activities, for example, oil solubilizers, vehicles, method 

of testing, etc. Therefore, this chapter reviews the common methods of testing antimicrobial and 

antioxidant activities of some Cymbopogon species and their major components, as well as factors 

affecting their activities. 

6.2 Factors aFFectIng antImIcrobIal actIVIty oF essentIal oIls 

6.2.1 so l u b i l i z i nG aG e n t s 

The main problem in the study of essential oil bioactivities is that they are poorly soluble in water. In 

order to overcome this problem, many authors have used various solvents. Examples of solubilizing 

agents used are provided in Table 6.1. 

However, interaction between essential oil components and solubilizer has to be taken into consideration. 

For example, Tween 20 (polyoxyethylene (2) sorbitan monolaurate) and Tween 80 (polysorbate 

80), which are the most commonly used nonionic solublizers, may cause either enhancement 

or reduction of antimicrobial activity. Interaction of essential oil with nonionic surfactants could 

be the result of either micellar solubilization or complex formation between the two molecules. The 

activity of essential oil depends on an adequate concentration of free oil existing in aqueous phase 

outside the micelle. At concentrations above critical micelle concentration (CMC) of the surfactants, 

antimicrobials solubilized within the micelles do not contribute to the antimicrobial activity, 

whereas at low concentrations below CMC, antimicrobial activity increases because of an increase 

in bacterial cell permeability to the antimicrobial compound (Russell et al. 1992). Reduction of the 

bioactivity of tea tree oil and thyme oil has been reported. It is possible that Tween 80 might inactivate 

phenolic compounds in those essential oils (cited in Mann and Markham 1998; Manou et al. 

1998). In addition, Hili et al. (1997) reported that the reduction of antimicrobial activity of cinnamon 

oil in the presence of dimethylsulphoxide (DMSO) might be due to the partitioning of the oil 

between the aqueous phase and DMSO, distancing the oil from cells. This effect, however, did not 

table 6.1 

essential oil-solubilizing agents 

oil-solubilizing 

agent 

concentration 

used organism assay method references 

Tween 20 0.001% v/v Fungi Broth microdilution method Devkatte et al. (2005) 

Tween 20 0.1% w/v Fungi Agar dilution method Tampieri et al. (2005) 

Tween 20 5% v/v Bacteria Agar dilution method Hammer et al. (1999) 

Tween 80 1% w/v Bacteria 

Yeast 

Agar diffusion method 

(Paper disk 6 mm) 

Jirovetz et al. (2007) 

Lertsatithanakorn et al. (2006) 

DMSO 0.2% v/v Bacteria Broth microdilution method Ohno et al. (2003) 

DMSO 1% v/v Fungi Agar dilution method Inouye et al. (2001) 

Ethanol 2%v/v Fungi Broth microdilution method Tullio et al. (2007) 

Ethyl acetate Pure Fungi Vapor contact method Inouye et al. (2001) 

DMSO + 

Tween 80 

Ethanol + 

Tween 80 

10% v/v DMSO + 

0.5% v/v Tween 80 

5% Ethanol + 

5% Tween 80 

Bacteria Agar diffusion method 

(Paper disk 6 mm) 

Prabuseenivasan et al. (2006) 

Bacteria 

Yeast 

Broth microdilution method Unpublished data

In Vitro Antimicrobial and Antioxidant Activities of Some Cymbopogon Species 169 

occur when low concentrations (0.15%–0.2% w/v) of bacteriological agar were used as a stabilizer 

of the oil–water mixture (Mann and Markham 1998; Remmal et al. 1993). 

6.2.2 ty Pe o f or G a n i s M 

The action of biocides depends on the type of microorganisms, which is mainly related to their 

cell wall structure and the outer membrane arrangement (Kalemba and Kunicka 2003; Russell 

et al. 1992). 

6.2.2.1 gram-Positive bacteria 

Gram-positive bacteria are more sensitive to biocides, particularly essential oil, than Gram-negative 

bacteria. Probably the main reason for this difference in sensitivity is the relative composition of the 

cell envelope. In general, the cell wall of Gram-positive bacteria is composed basically of peptidoglycan, 

which forms a thick, fibrous layer. Many antimicrobial agents much penetrate the outer and 

cytoplasm membranes to reach their site of action. The effects of various disinfectants, antiseptics, 

and preservatives on Gram-positive bacteria have been well documented. The action of essential 

oils against Gram-positive bacteria and fungi appears to be similar. The oil components destroy 

the bacterial and fungal cell wall and cytoplasmic membrane, causing a leakage of cytoplasm and 

coagulation. They also inhibit the synthesis of DNA, RNA, proteins, and polysaccharides in fungal 

and bacterial cells (Himejima and Kubo 1993; Zani et al. 1991). 

6.2.2.2 gram-negative bacteria 

Gram-negative bacteria, especially Escherichia coli, Klebsiella spp., Proteus spp., Pseudomonas 

aeruginosa, and Seratia macescens, appear to be increasingly implicated as hospital pathogens. 

Gram-positive bacteria are more sensitive to essential oils than Gram-negative bacteria. Pseudomonas 

aeruginosa, for example, is resistant to a wide variety of essential oils due to the hydrophilic 

surface of their outer membrane, which is rich in lipopolysaccharide molecules. Thus, essential oil 

constituents are unable to penetrate the membrane barrier (Nikaido 1994). Essential oils containing 

phenolic compounds such as carvarcrol and thymol cause the outer cell membrane damage 

(Helander et al. 1998). However, palmarosa, lemongrass, peppermint, and eucalyptus oils are found 

to be bactericidal to Escherichia coli strain SP-11. Only peppermint and palmarosa oils induced the 

formation of elongated filamentous forms of E. coli (Pattnaik et al. 1995b). 

6.2.2.3 mould and yeast 

Yeast and mould comprise important groups of microorganisms that are responsible for several 

infections and for causing spoilage of foods, pharmaceutical products, and cosmetic products. Some 

fungal species are of agricultural and industrial importance and many cause disease in plants. 

Antifungal activity of some Cymbopogon species has been reported. For example, the mycelium 

growth of Aspergillus niger is inhibited by C. nardus essential oil. It causes morphological changes 

such as hyphal diameter and hyphal wall thinning, plasma membrane disruption, and mitochondria 

structure disorganization (de Billerberk et al. 2001). Lemongrass oil is an effective postharvest 

fungitoxicant of higher-order plant origin, potentially suitable for protection of foodstuffs against 

storage fungi (Mishra and Dubey 1994). Palmarosa oil had some inhibitory activity against 12 

fungi. The response of this oil is dependent on the species of fungi (Pattnaik et al. 1996). Moreover, 

palmarosa oil also has antimicrobial against yeast cell, Saccharomyces cerevisiae, by passively 

entering the plasma membrane to initiate membrane disruptions followed by accumulation in the 

plasma membrane resulting in the inhibition of cell growth (Prashar et al. 2003). 

6.2.3 th e Co r r e l at i o n b e t w e e n oil Co M P o n e n t s a n d aCtiVity 

Biological activity of an essential oil is in strict direct relationship to its chemical composition. 

The relation between components and activity may be attributed both to their major components


and to the minor ones present in the oils. The antibacterial action of essential oils depends on the 

chemical structure of their components. Phenolic compounds such as eugenol and carvacrol have 

an aromatic nucleus and phenolic OH group that is known to be reactive and to form hydrogen 

bonds with active sites of target enzymes (Farag et al. 1989). Mahmoud (1994) reported that geraniol, 

nerol, and citronellol, which are aliphatic alcohols, are broad-spectrum antifungal agents. The 

effectiveness of essential oil is higher than the activity of each component. It is possible that major 

components and minor compounds may act together synergistically to contribute to the activity 

(Milos et al. 2000). 

6.2.4 Me t h o d s Co M M o n ly used f o r an t iM iC r o b i a l assessMent o f es s e n t i a l oil 

Although there are the nonconventional methods for determining the minimum inhibitory concentration 

of essential oils (Kalemba and Kunicka 2003; Mann and Markham 1998), only the basic 

techniques commonly used for assessment of antibacterial and antifungal activities of essential 

oil, which are serial broth dilution method and agar dilution method, are stated. In the case of estimation 

of essential oil activity on vapor contact assay, the agar diffusion method is slightly modified. 

Antimicrobial activity of some Cymbopogon species and their major components is shown in 

Tables 6.2 and 6.3, respectively. However, Janssen et al. (1987) noted that the antimicrobial activity 

from different methods is not necessarily comparable. 

6.2.4.1 the serial broth dilution method 

Essential oil is dissolved in a solubilizing agent, which is nontoxic to microorganisms, before 

being serially diluted in an appropriate broth or agar. The effectiveness of essential oil is generally 

expressed as minimum inhibitory concentration (MIC), which is defined as the lowest concentration 

of essential oil that inhibits the visible growth, and as minimum bactericidal concentration (MCC) 

and minimum fungicidal concentration (MFC), which are defined as the lowest concentration of 

essential oil that causes more than 99.9% reduction of microorganism number or 3 log reduction 

of microorganisms (Kalemba and Kunicka 2003). 

6.2.4.2 the agar diffusion method 

The agar diffusion method is generally recommended as a prescreening method for a large number 

of essential oils since it is easy to perform and requires a small amount of essential oil. An assay can 

be performed accordingly; an appropriate nutrient agar plate is inoculated with microorganisms, 

either by adding the organism to the agar before it is poured or by streaking the organisms across 

the surface of the plate. The amount of essential oil tested can be accurately incorporated either 

on paper disk or into the well. The effectiveness of essential oil is demonstrated by the size of the 

microorganism inhibition zone around the disk or well, and it is usually expressed as the diameter 

of the zone. However, the disadvantages of this method are that essential oils are likely to evaporate 

with solvent during the incubation period, and they may show limited agar diffusion. Moreover, the 

inhibition zone of the oils depends on the characteristics of the oil components partitioned through 

the agar (Kalemba and Kunicka 2003; Southwell et al. 1993). 

6.2.4.3 Vapor contact assay 

This method is used for evaluating the activity of essential oils that are to be employed as atmospheric 

biocides (Lopez 2005; Tullio et al. 2006). An appropriate nutrient agar plate is inoculated 

with microorganisms. Essential oil is diluted in organic solvent such as ethyl acetate, ethyl 

ether, and ethanol. The exact amount of diluted essential oil is added to a paper disk, attached to 

the lid of a petri dish, and completely sealed; the lid is then inverted and incubated. The results 

are expressed as minimum inhibitory dose (MID), which is defined as the lowest concentration 

of essential oil (mg/L in air) that inhibits visible growth. In some studies, the soaked paper disk 

is placed in the airtight box next to the agar plate (Inouye et al. 2001; Nakahara et al. 2003).


table 6.2 

In Vitro antimicrobial activity of Cymbopogon essential oils 

Cymbopogon Cymbopogon Cymbopogon Cymbopogon Cymbopogon 

Cymbopogon citratus flexuosus (Indian giganteus martinii nardus (ceylon winterianeous 

organisms 

(lemongrass ) 

lemongrass) (tsauri grass) (palmarosa) 

citronella) (Java citronella) references 

bacteria 

Acinetobacter MIC 0.03% v/v MIC 0.12% v/v MIC 0.25% v/v Hammer et al. (1999) 

baumaii 

Aeromonas MIC 0.12% v/v MIC 0.12% v/v nd Hammer et al. (1999) 

sobria 

Bacillus brevis MIC 0.16 µL/mL MICa 1.66 µL/mL Kalemba and Kunicka 

(2003) 

Campylobacter 15 µL in 6 mm paper disk: 

15 µL in 6 mm paper 

Wannissorn et al. 

jejuni 

Inhibition zone 90 mm 

disk: Inhibition 

(2005) 

zone 40 mm 

Clostridium 15 µL in 6 mm paper disk: 



perfringens Inhibition zone 90 mm 


(2005) 

zone 39.5 mm 

Enterococcus MIC 0.12% v/v Leaf and stem MIC 0.25% v/v MIC 1.0% v/v Hammer et al. (1999) 

faecalis 

MIC 60 and 

600 ppm 

Escherichia coli MIC 0.06% v/v 

MIC > 0.8% v/v Leaf and stem MIC 0.06–0.12% v/v MIC 0.25–0.5% v/v MIC > 0.8% v/v Hammer et al. (1999) 

MIC > 0.8% v/v 

MIC 60 ppm MIC 0.12% v/v MIC > 0.8% v/v 

Inouye et al. (2001) 

MCC 0.12% v/v 

MIC 0.2% v/v MCC 0.25% v/v 

Oussalah et al. (2007) 

MCC 1.66 µL/mL 

MCC 1.66 µL/mL 15 µL in 6 mm paper 

Pattnaik (1995a) 

MID 100 mg/L, air 



15 µL in 6 mm paper disk: 

zone 10.5 mm 

(2005) 


Haemophilus MID 1.56 mg/L, air Inouye et al. (2001) 

influenzae 

Helicobacter MIC




Cymbopogon Cymbopogon Cymbopogon Cymbopogon Cymbopogon 

Cymbopogon citratus flexuosus (Indian giganteus martinii nardus (ceylon winterianeous 

(lemongrass ) 

lemongrass) (tsauri grass) (palmarosa) 

citronella) (Java citronella) references 

MIC 0.25% v/v Leaf and stem MIC 0.25% v/v MIC 1.0% v/v Hammer et al. (1999) 

MIC 60 ppm 

MIC 0.4% v/v MIC 0.4% v/v MIC 0.2% v/v MIC 0.8% v/v MIC 0.4% v/v Oussalah et al. (2007) 

organisms 

Lertsatitthanakorn 

et al. (2006) 

MIC 0.6 µL/mL 

MCC 0.6 µL/mL 

Klebsiella 

pneumoniae 

Listeria 

monocytogenes 

Propionibacterium 

acnes 

MIC 0.005– 

0.3 µL/mL 

MCC 0.625– 

1.2 µL/mL 

MIC 1.0% v/v 

Leaf and stem MIC > 2.0% v/v MIC > 2.0% v/v Hammer et al. (1999) 


MIC 60 ppm 

Kalemba and Kunicka 

(2003) 

MIC 0.8% w/v MIC 0.8% w/v MIC 0.2% w/v MIC 0.4% w/v MIC > 0.8% w/v Oussalah et al. (2006) 

Pseudomonas 

aeruginosa 

MIC 0.4% v/v MIC 0.5% v/v 

MIC 0.2% v/v 


Pseudomonas 

putida 

Salmonella 

typhimurium 

MIC 0.4% v/v Hammer et al. (1999) 


(2003) 



MIC > 2.0% v/v 

MIC 0.8% v/v 



zone 24 mm 

MIC 0.25% v/v 

MIC 0.8% v/v 




(2005) 

MIC 0.25% v/v MIC 0.25% v/v MIC > 2.0% v/v Hammer et al. (1999) 

Serratia 

marcescens 

Staphylococcus 

aureus 

MIC 0.05% v/v Hammer et al. (1999) 



(2003) 


MIC 0.12–0.25% v/v 

MIC 0.4% v/v 

MCC 0.25% v/v 

MIC 0.12% v/v 

MIC 0.1% v/v 


MCC 0.12% v/v 

MIC 0.1% v/v Leaf and stem 

MIC 60 ppm 

MIC 0.06% v/v 

MIC 0.1% v/v 


MCC 0.06% v/v 

MID 12.5 mg/L, air


MID 6.25 mg/L, air Inouye et al. (2001) 

MID 6.25 mg/L, air Inouye et al. (2001) 


(2005) 

15 µL in 6 mm 

paper disk: 

Inhibition zone 



Streptococcus 

pyogenes 

Streptococcus 

pneumoniae 

Streptococcus 

enteritidis 

12.8 mm 

Vibrio cholerae MIC 0.3 µL/mL MIC 0.66 µL/mL Kalemba and Kunicka 

(2003) 

MID 800 mg/L, air Pawar and Thaker 

(2006) 

yeast and Fungi 


disk: Hyphae 

inhibition zone 

8 mm 

Spore inhibition 

zone 12 mm 

Aspergillus niger 5 µL in 5 mm paper disk: 

Hyphae inhibition zone 

21 mm 

Spore inhibition zone 

33 mm 

MID 250 mg/L, air Paranagama et al. 

(2003) 

Nakahara et al. (2003) 

Aspergillus flavus MIC 0.6 mg/mL 

MFC 1.0 mg/mL 

MIC 0.6 mg/mL Hammer et al. (1999) 

Devkatte et al. (2005) 

Lertsatithanakorn 

et al. (2005) 

Tampieri et al. (2005) 

Duarte et al. (2005) 

Dutta et al. (2006) 

Jirovetz et al. (2007) 

De Billerbeck et al. 

(2001) 

MID 250 mg/L, air Nakahara et al. (2003) 

MIC 0.12% v/v; 

0.5–1.0% v/v 

MFCa 0.12% v/v; 

2.0% v/v 

Mycelium growth 

inhibited at 

800 mg/L 

MIC 0.06–0.12% v/v 

MFC 0.12% v/v 

Leaf and stem 

MIC 60 ppm 

MIC 500 ppm 

MIC > 0.2 mg/mL 

Candida albicans MIC 0.06% v/v 

MIC 322 µg/mL 

MFC 0.06–0.12% v/v 

Eurotium 

amstelodami 





Cymbopogon 

winterianeous 

(Java citronella) references 

Cymbopogon 

nardus (ceylon 

citronella) 

Cymbopogon 

martinii 

(palmarosa) 

Cymbopogon 

giganteus 

(tsauri grass) 

Cymbopogon 

flexuosus (Indian 

lemongrass) 

Cymbopogon citratus 

(lemongrass ) 

organisms 






MIC 0.2 mg/mL MFC 0.1% v/v Prashar et al. (2003) 

Sacchetti et al. (2005) 

MID 1 µg/mL, air 


MFD 5.2 µg/mL, air 




MIC 50 µg/mL; 0.25 µL/mL 

(2003) 

Eurotium 

chevalieri 

Penicillium 

adametzii 

Penicillium 

citrinum 

Penicillium 

griseofulvum 

Penicillium 

islandicum 

Saccharamyces 

cerevisiae 

Tricophyton 

mentagrophytes 


MFC 15.2 µg/mL 

MID 1 µg/mL, air 


MIC 50 µg/mL 

MFC 15.2 µg/mL 

Tricophyton 

rubrum 

a Does not indicate species.


table 6.3 

In Vitro antimicrobial activity of the major components of Cymbopogon essential oils 

alcohols aldehydes ester terpene hydrocarbons 

references 

Rosato et al. (2007) 

Van Zyl et al. 

(2006) 

geraniol citronellol citral citronellal geranyl acetate limonene mycene 

MIC 234.9 ± 

0.0 mM 

MIC 163.0 ± 

29.0 mM 

MIC 0.70 mg/mL MIC > 207.5 ± 

45.4 mM 

Bacillus cereus MIC 0.7 mg/mL 

MIC 51.9 mM 



Si et al. (2006) 


(2006) 

MID > 800 

mg/L air 

MIC 176.2 ± 

40.4 mM 

MIC > 163.0 ± 

51.0 mM 

MIC 207.5 ± 

64.8 mM 

Bacillus subtilis MIC 0.8 mg/mL MIC 0.35 mg/mL 

Escherichia coli MID > 25 mg/L air MIC 1.4 mg/mL MID > 12.5 mg/L 

MIC 1.4 mg/mL 

air 

MBC 283–300 µg/mL 

MIC 25.9 ± 0.0 mM 

MID 200 mg/L 

air 

MID 6.25 mg/L air MID 3.13 mg/L 

air 

MIC 1000 µg/mL MIC 500 µg/mL Kalemba and 

Kunicka (2003) 

MIC 0.375 mg/mL Kalemba and 


MID 400 mg/L 

air 

MID 200–400 

mg/L air 


air 


air 

Tampieri et al. 

(2005) 


MIC 1000 ppm 

MIC 163.0 ± 

0.0 mM 

MIC 100 ppm MIC 77.8 ± 

0.0 mM 

MIC 100 ppm 

MIC 19.5 ± 0.0 mM 

Haemophilus 

influenzae 

Listeria 

monocytogenes 

Pseudomonas 

aeruginosa 

Streptococcus 

pyogenes 

Streptococcus 

pneumoniae 

Candida 

albicans 

MIC 73.4 ± 0.0 

mM 

(2006) 

MIC 500 µg/mL Kalemba and 


Si et al. (2006) 

(continued on next page) 

MIC 500 µg/mL 

MBC 367 µg/mL 

Salmonella 

typhimurium



In Vitro antimicrobial activity of the major components of Cymbopogon essential oils 

alcohols aldehydes ester terpene hydrocarbons 

geraniol citronellol citral citronellal geranyl acetate limonene mycene references 

MID > 25 mg/L, air MIC 0.70 mg/mL MID 12.5 mg/L, MIC 129.7 ± MIC > 163.0 ± MID 800 mg/L, 


MIC 0.7 mg/mL 

air 

55.1 mM 

35.7 mM air 


MIC 38.9 ± 18.2 mM 

MIC 176.2 ± 


40.4 mM 

(2006) 

MIC 0.125 mg/mL Kalemba and 


No activity No activity No activity Potent activity No activity No activity No activity Nakahara et al. 


(2003) 

MIC 500 ppm MIC 500 ppm No activity Potent activity No activity No activity No activity Kalemba and 

No activity 

No activity 



Nakahara et al. 

(2003) 



(2003) 

1.0 mM growth 1.0 mM growth 1.0 and 2.0 mM 2.0 mM growth 

2.0 mM growth 2.0 mM Kurita et al. 1981 

inhibition > 20 days inhibition > growth 

inhibition 0 days 

inhibition growth 

20 days 

inhibition 3 and 

0 days 

inhibition 

> 20 days, 

0 days 

respectively 



(2003) 


aureus 


epidermidis 

Aspergillus 

candidus 

Aspergillus 

flavus 

Aspergillus 

versicolor 

Aspergillus 

nidulans 

Eurotium 

amstelodami


No activity No activity No activity Nakahara et al. 

(2003) 


(2003) 


(2003) 


(2003) 


(2003) 


No activity Moderate activity Moderate activity Potent activity 


No activity No activity No activity Potent activity 






Moderate activity No activity Moderate activity Potent activity 


MIC 25 µg/mL 

MFC 7.7 ± 

1.85 µg/mL 

MID 0.5 µg/L, air 

MFC 3.9 ± 

1.2 µg/L, air 

1.0 mM growth 1.0 mM growth 1.0 mM growth 1.0 mM growth 

inhibition > 20 days inhibition > inhibition > inhibition 0 days 

20 days 

20 days 

2.0 mM growth 

inhibition 2 days 

Eurotium 

chevalieri 

Penicillium 

adametzii 

Penicillium 

citrinum 

Penicillium 

griseofulvum 

Penicillium 

islandicum 

Tricophyton 

mentagrophytes 

Kurita et al. 1981 

2.0 mM 

growth 

inhibition 

0 days 

2.0 mM growth 

inhibition 

0 days 

Tricophyton 

rubrum


6.3 In VItro antIoxIdant actIVIty oF some Cymbopogon sPecIes 

and theIr maJor comPonents 

Essential oils and their components are gaining increasing interest because of their potential for 

multipurpose functional use. Apart from antimicrobial and antifungal properties, antioxidant and 

radical-scavenging properties are of great interest to health and food science researchers. An antioxidant 

may be defined as any substance that delays or inhibits oxidation of that substrate. In vitro methods 

provide a useful indication of antioxidant activity. Due to the differences between in vitro testing 

and biological environments, the data obtained from in vitro methods are difficult to apply to biological 

systems (Antolovich et al. 2002). Antioxidant activity can be divided into two classes: primary 

(chain-breaking or radical-scavenging antioxidants) and secondary (preventive antioxidants) 

(Laguerre et al. 2007). Frankel and Meyer (2000) pointed out that multifaceted testing of antioxidant 

activity is needed because antioxidants often act via mixed mechanisms. Essential oils are a 

very complex mixture that can contain two or three major components at fairly high concentrations 

and other components in trace amounts (Bakkali et al. 2008). The antioxidant activity of essential 

oils, therefore, would be associated with various mechanisms. In this review, only the common 

in vitro antioxidant testing methods for essential oils are mentioned. 

6.3.1 fa C t o r s affeC tinG an t i o x i d a n t aCtiVity 

The antioxidant activity of essential oils and their components shows the marked difference between 

the reported results (Table 6.4), which depend on many factors. The magnitudes of antioxidant 

activities, therefore, could only be compared for given process conditions. In this review, studies 

on the antioxidant activity of Cymbopogon species and their major components published in the 

literature are reported, and only factors affecting their antioxidant activity, using the three methods 

of testing mentioned earlier, are discussed. 

6.3.1.1 choice of oxidizable substrate and end-Product evaluation 

The choice of an oxidizable substrate depends on whether the antioxidant is for nutritional, therapeutic, 

or preservative purposes. It is important to select a substrate that is representative of in situ 

conditions. Since the aim of assessing antioxidant efficacy of essential oils is to preserve foods, 

the oxidizable substrate normally used to evaluate antioxidant activity is either linoleic acid or 

homogenized egg yolk (Laguerre et al. 2007). Therefore, the methods often used for this assessment 

are β-carotene bleaching assay and TBARS assay. However, a limitation of evaluating antioxidant 

activity by TBARS assay is that thiobarbituric acid not only reacts with MDA, which is a secondary 

oxidation product of lipid peroxidation but also can react with other aldehydes (Janero 1990). 

Thus, essential oils containing aldehyde compounds such as citral, citronellal, heptanal, octanal, 

etc., may cause an underestimation of their antioxidant activity. This evidence can be seen in the 

study of Ruberto and Baratta (2000), which found that antioxidant activity of aldehyde compounds 

can be assessed by determination of conjugate diene hydroperoxides, which are primary oxidation 

products of linoleic acid peroxidation but undetectable with TBARS assay. 

6.3.1.2 media 

There are two major types of media: homogeneous medium and heterogeneous medium. In a heterogeneous 

medium, the type of solvent could affect the antioxidant mechanism. Antioxidants 

behave differently in media with different polarities. For example, DPPH is a stable-free radical, but 

it is sensitive to some Lewis bases, solvent types, light, and oxygen. Polar solvents may decrease the 

odd electron density of the nitrogen atom in DPPH and increase the reactivity of DPPH. In general, 

DPPH in the methanol buffer system shows better stability than in the acetone buffer system (pH 

10) (Ozcelik et al. 2003). Porter (1993) described the “polar paradox”: lipophilic antioxidants are


table 6.4 

In Vitro antioxidant activity of Cymbopogon species and their major components 

sample antioxidant activity method of testing references 

Citronellol AI at 1000 ppm = 27.5% 

AI at 0.001 M = 13.3% 

IC50 =>1000 µg/mL 

AI at 10 µL/mL = 15.9% 

Geraniol AI at 1000 ppm = 34.9% 

AI at .001 M = 26.5% 

IC50 => 1000 µg/mL 

AI at 10 µL/mL = 19.7% 

Limonene AI at 1000 ppm = 27.4% 

AI at 10 µL/mL = 22.2% 

AI at 0.001 M = 21.0% 

Alpha tocopherol AI at 1000 ppm = 93.5% 

AI at 0.001 M = 94.8% 

C. citratus AI at 5 µL/mL = 26.0% 

AI at 10 µL/mL = 31.6% 

IC50 = 27.0 µL/mL 

AI at 10 µL/mL = 63.8% 

AI at 2 µL/mL = approx 50% 

C. nardus IC50 = 2.0 µL/mL 

AI at 5 µL/mL = 89.0% 

AI at 10 µL/mL = 45.5% 

Citronellal AI at 1000 ppm = not detectable 

AI at 0.001 M = 21.9% 

AI at 10 µL/mL = 16.4% 

Citral AI at 1000 ppm = not detectable 

AI at 0.0001 M = 18.3% 

IC50 => 1000 µg/mL 

AI at 10 µL/mL = 21.1% 

TBARS method 

Conjugated diene formation 

DPPH test 

DPPH test 

TBARS method 


DPPH test 

DPPH test 

TBARS method 

DPPH test 



TBARS method 

TBARS method 

TBARS method 

DPPH test 

DPPH test 

β-carotene bleaching assay 

DPPH test 

DPPH test 

TBARS method 

TBARS method 


DPPH test 

TBARS method 


DPPH test 

DPPH test 

Ruberto et al. (2000) 


Hierro et al. (2004) 

Unpublished data 












Lertsatittanakorn et al. (2006) 



Lertsatittanakorn et al. (2006) 










more active in a polar medium, whereas polar antioxidants are more active in a lipophilic medium. 

In a heterogeneous medium, either in oil in water emulsion or aqueous suspensions of liposome or 

LDLs, oxidation is affected by the type of interface and its viscosity, the size distribution of oil and 

liposome droplets, the partition and diffusion of oxygen toward reaction centers, and the antioxidant 

location. According to Porter’s polar paradox, in emulsion media, oxidation occurs at the oil–water 

interface, where lipophilic antioxidants are more efficient than hydrophilic antioxidants. In addition, 

lipid peroxidation is dependent on the pH of water in oil emulsion and in liposomes (Laguerre 

et al. 2007). Frankel (1998) reported that lipid oxidation is generally lower at high pH and, consequently, 

the oxidation rate increases as pH decreases. 

6.3.1.3 oxidation conditions 

Heat: Since essential oils are very volatile and undergo thermal degradation at high temperature, 

temperature is an important factor when assessing the extent of oxidation. It is, 

therefore, important to carry out tests at temperatures close to natural conditions, such as 

ambient or physiological temperatures (Laguerre et al. 2007). 

ROO peroxy radicals: ROO · peroxy radicals are a prime target for assessing antiradical activity. 

Azoinitiators are commonly used for ROO · generation. In β-carotene and TBARS


assays, a water-soluble 2,2′-Azobis(2-amidopropane)dihydrochloride (AAPH or ABAP) is 

most commonly used for ROO · generation. Hanlon and Seybert (1997) found that ABAP 

dramatically increased the rate of lipid peroxidation as pH increased from 5 to 7, and 

began to plateau at a pH of about 8. In addition, the rate of lipid peroxidation depends on 

temperature and the viscosity of the medium. It is likely that as the rate of ROO · diffusion 

increases, the rate of lipid peroxidation increases (Laguerre et al. 2007). 

6.3.1.4 methods commonly used for testing antioxidant activity of essential oils 

Three common methods used to evaluate antioxidant activity of essential oils are the β-carotene 

bleaching method, DPPH free radicals scavenging method, and thiobarbituric acid reactive species 

assay (TBARS). The principles of the assays are described in the following subsections. 

6.3.1.4.1 β-Carotene Bleaching Assay 

This method is based on the result of β-carotene oxidation by linoleic acid degradation products, 

which are catalyzed by heat. Tween is used for dispersion of linoleic acid and β-carotene in the aqueous 

phase. The addition of an antioxidant results in retarding β-carotene bleaching. Quantitative 

analysis of β-carotene is measured by UV spectrophotometry at 470 nm (Laguerre et al. 2007). 

Results are expressed as the percentage inhibition of β-carotene bleaching (Gachkar et al. 2007; 

Kulisic et al. 2004; Sacchetti et al. 2005; Wang et al. 2008), the relative antioxidant activity (RAA%) 

of the sample and butylated hydroxyltoluene (BHT) (Obame et al. 2007), or IC 50, which is a sample 

concentration providing 50% inhibition (Khadri et al. 2008). 

6.3.1.4.2 2,2-Diphenyl-1-Perylhydrazyl Free Radicals Scavenging Test (DPPH Test) 

The DPPH test is based on the reduction of 2,2-diphenyl-1-perylhydrazyl free radicals (DPPH) in 

the presence of hydrogen-donating antioxidant or free radical scavenging agent (Kulisic et al. 2004). 

The DPPH radical absorbs at 517 nm, and antioxidant activity can be determined by monitoring the 

decrease of DPPH radical. Results are expressed as EC 50, that is, the amount of antioxidant necessary 

to decrease the initial DPPH concentration by 50% (Antolovich et al. 2002; Lertsatitthanakorn 

et al. 2006; Demirci et al. 2007), or the percentage inhibition of DPPH radical (Gachkar et al. 2007; 

Khadri et al. 2008; Kulisic et al. 2004; Obame et al. 2007; Sacchetti et al. 2005; Singh et al. 2005; 

Wang et al. 2008). 

6.3.1.4.3 Thiobarbituric Acid Reactive Substances (TBARS) Assay 

This method is commonly used to detect lipid oxidation. This procedure measures malonaldehyde 

(MDA) formation, which is the split product and endoperoxide of unsaturated fatty acids resulting 

from oxidation of a lipid substrate. The MDA is reacted with thiobarbituric acid to form a pink pigment 

that is measured spectrophotometrically at 532–535 nm (Antolovich et al. 2002). Results may 

be expressed as the percentage inhibition of oxidation (AI%) (Ruberto and Baratta 2000; Kulisic 

et al. 2004) or thiobarbituric acid value (meq of malonaldehyde/g) (Singh et al. 2005). 

6.4 summary 

The results given in the literature suggest that essential oils from some Cymbopogon species show 

antimicrobial activity against a wide range of bacteria and fungal species, and also have a weakto-moderate 

antioxidant activity. Although the oils are used as fragrance in perfumery and in the 

food and beverage industry, they may also have great potential for protection of food and cosmetics 

from microbial spoilage and as a topical antiseptic. However, because it has weak-to-moderate 

antioxidant activity, using the oils to prevent oxidative deterioration of lipids in food might be helpful 

for a certain period of time.


reFerences 

Antolovich, M., Prenzler, P., Patsalides, E., McDonald, S., Robards, K., 2002. Methods for testing antioxidant 

activity. Analyst 127, 183–198. 

Bakkali, F., Averbeck, A., Averbeck, V.D., Idaomar, M., 2008. Biological effects of essential oils—A review. 

Food and Chemistry Toxicology 46, 446–475. 

de Billerbeck, V., Roque, C., Bessiere, J., Fonvieille, J., Dargent, R., 2001. Effects of Cymbopogon nardus (L.) 

W. Watson essential oil on the growth and morphogenesis of Aspergillus niger. Canadian Journal of 

Microbiology 47, 9–17. 

Demirci, B., Kosar, M., Demirci, F., Dinc, M., Baser, K.H.C., 2007. Antimicrobial and antioxidant activities of 

the essential oil of Chaerophyllum libanoticum Boiss. et Kotschy. Food Chemistry 105, 1512–1517. 

Devkatte, A.N., Zore, G.B., Karuppayil, S.M., 2005. Potential of plant oils as inhibitors of Candida albicans 

growth. FEMS Yeast Research 5, 867–873. 

Duarte, M.C., Figueira, G.M., Sartoratta, A., Rehder, V.L., Delarmeliva, C., 2005. Anti-candida activity of 

Brazilian medicinal plants. Journal of Ethnopharmacology 97, 305–311. 

Dutta, B.K., Karmakar, S., Naglot, A., Aich, J.C., Begam, M., 2006. Anticandidial activity of some essential 

oils of a mega biodiversity hotspot in India. Mycoses 50, 121–124. 

Farag, R.S., Daw, Z.Y., Abo-Raya, S.H., 1989. Influence of some spice essential oils on Aspergillus parasiticus 

growth and production of aflatoxins in a synthetic medium. Journal of Food Science 54, 74–76. 

Frankel, E., 1998. Lipid Oxidation. The Oily Press, Dundee, U.K. 

Frankel, E., Meyer, A., 2000. The problems of using one-dimensional methods to evaluate multifunctional food 

and biological antioxidants. Journal of Science Food Agriculture 80, 1925–1941. 

Gachkar, L., Yadegari, D., Rezaei, M.B., Taghizadeh, M., Astaneh, S.A., Rasooli, I., 2007. Chemical and biological 

characteristics of Cuminum cyminum and Rosmarinus officinalis essential oils. Food Chemistry 

102, 898–904. 

Hammer, K.A., Carson, C.F., Riley, T.V., 1999. Antimicrobial activity of essential oils and other plant extracts. 

Journal of Applied Microbiology 86, 985–990. 

Hanlon, M., Seybert, D., 1997. The pH dependence of lipid peroxidation using water-soluble azo initiators. 

Free Radical Biological Medicine 23, 712–719. 

Helander, I.M., Alakomi, H., Latva-Kala, K., Mattila-Sandholm, T., Pol, I., Smid, E., Gorris, L.G.M., 

von Wright, A., 1998. Characterization of the action of selected essential oil components on Gramnegative 

bacteria. Journal of Agricultural and Food Chemistry 46, 3590–3595. 

Hierro, I., Valero, A., Perez, P., Gonzalez, P., Cabo, M.M., Montilla, M.P., Navarro, M.C., 2004. Action of different 

monoterpenic compounds against Anisakis simplex s.l. L3 larvae. Phytomedicine 11, 77–82. 

Hili, P., Evans, C.S., Veness, R.G., 1997. Antimicrobial action of essential oils: The effect of dimethylsulphoxide 

on the activity of cinnamon oil. Letters in Applied Microbiology 24, 269–275. 

Himejima, M., Kubo, I., 1993. Fungicidal activity of polygodial in combination with anethole and indole 

against Candida albicans. Journal of Agricultural and Food Chemistry 41, 1776–1779. 

Inouye, S., Takizawa , T., Yamaguchi, H., 2001. Antibacterial activity of essential oils and their major constituents 

against respiratory tract pathogens by gaseous contact. Journal of Antimicrobial Chemotherapy 47, 565–573. 

Inouye, S., Uchida, K., Abe, S., 2006. Vapor activity of 72 essential oils against a Trichophyton mentagrophytes. 

Journal of Infection and Chemotherapy 12, 210–216. 

Janero, D.R., 1990. Malondialdehyde and thiobarbituric acid-reactivity as diagnostic indices of lipid peroxidation 

and peroxidative tissue injury. Free Radical Biology and Medicine 9, 515–540. 

Janssen, A.M., Scheffer, J.J.C., Svendsen, A.B., 1987. Antimicrobial activity of essential oils: A 1976–1986 

literature review. Aspects of the test methods. Planta Medica 53, 395–398. 

Jirovetz, L., Buchbauer, G., Gernot, N., Benoit, M.M., Pierre, M., 2007. Composition and antimicrobial activity 

of Cymbopogon giganteus (Hochst.) Chiov. Essential flower, leaf and stem oils from Cameroon. Journal 

of Essential Oil Research 19, 485–489. 

Kalemba, D., Kunicka, A., 2003. Antibacterial and antifungal properties of essential oils. Current Medicinal 

Chemistry 10, 813–829. 

Khadri, A., Serralheiro, M.L.M., Nogueira, J.M.F., Neffati, M., Smiti, S., Araujo, M.E.M., 2008. Antioxidant 

and antiacetylcholinesterase activities of essential oils from Cymbopogon schoenanthus L. Spreng. 

Determination of chemical composition by GC-mass spectrometry and 13C NMR. Food Chemistry 109, 

630–637. 

Kulisic, T., Radonic, A., Katalinic, V., Milos, M., 2004. Use of different methods for testing antioxidative activity 

of oregano essential oil. Food Chemistry 85, 633–640.


Kurita, N., Miyaji, M., Kurane, R., 1981. Antifungal activity of components of essential oils. Agricultural and 

Biological Chemistry 45, 945–952. 

Laguerre, M., Lecomte, J., Villeneuve, P., 2007. Evaluation of the ability of antioxidants to counteract lipid 

oxidation: Existing methods, new trends and challenges. Progress in Lipid Research 46, 244–282. 

Lertsatitthanakorn, P., Taweechaisupapong, S., Aromdee, C., Khunkitti, W., 2006. In vitro bioactivities of 

essential oils used for acne control. International Journal of Aromatherapy 16, 43–49. 

Lopez, P., Sanchez, C., Batlle, R., Nerin, C., 2005. Solid- and vapor-phase antimicrobial activities of six essential 

oils: Susceptibility of selected foodborne bacterial and fungal strains. Journal of Agricultural and 

Food Chemistry 53, 6939–6946. 

Mahmoud, A.L., 1994. Antifungal action and antiaflatoxigenic properties of some essential oil constituents. 

Letters in Applied Microbiology 19, 110–113. 

Mann, C.M., Markham, J.L., 1998. A new method for determining the minimum inhibitory concentration of 

essential oils. Journal of Applied Microbiology 84, 538–544. 

Manou, I., Bouillard, L., Devleeschouwer, M.J., Barel, A.O., 1998. Evaluation of the preservative properties of 

Thymus vulgaris essential oil in topically applied formulations under a challenge test. Journal of Applied 

Microbiology 84, 368–376. 

Milos, M., Mastelic, J., Jerkovic, I., 2000. Chemical composition and antioxidant effect of glycosidically bound 

volatile compounds from oregano (Origanum vulgare L. ssp. hirtum). Food Chemistry 71, 79–83. 

Mishra, A.K., Dubey, N.K., 1994. Evaluation of some essential oils for their toxicity against fungi causing 

deterioration of stored food commodities. Applied and Environmental Microbiology 60, 1101–1105. 

Nakahara, K., Alzoreky, N., Yoshihashi, T., Nguyen, H., Trakoontivakorn, G., 2003. Chemical composition 

and antifungal activity of essential oil from Cymbopogon nardus (Citronella grass). Japan Agricultural 

Research Quarterly 37, 249–252. 

Nikaido, H., 1994. Prevention of drug access to bacterial targets: Permeability barriers and active efflux. 

Science 264, 382–388. 

Obame, L., Koudou, J., Chalchat, J., Boassole, I., Edou, P., Ouattara, A., Traore, A., 2007. Volatile components, 

antioxidant and antibacterial activities of Dacryodes buettneri H.J. Lam. essential oil from Gabon. 

Scientific Research and Essay 2, 491–495. 

Ohno, T., Kita, M., Yamaoka, Y., Imamura, S., Yamamoto, T., Mitsufuji, S., Kodama, T., Kashima, K., Imanishi, 

J., 2003. Antimicrobial activity of essential oils against Helicobacter pylori. Helicobacter 8, 207–215. 

Oussalah, M., Caillet, S., Saucier, L., Lacroix, M., 2006. Antimicrobial effects of selected plant essential oils on 

the growth of a Pseudomonas putida strain isolated from meat. Meat Science 73, 236–244. 

Ozcelik, B., Lee, J.H., Min, D.B., 2003. Effects of light, oxygen, and pH on the absorbance of 2,2-diphenyl-1picrylhydrazyl. 

Journal of Food Science 68, 487–490. 

Paranagama, P.A., Abeysekera, K.H.T., Abeywickrama, K., Nugaliyadde, L., 2003. Fungicidal and anti-aflatoxigenic 

effects of the essential oil of Cymbopogon citratus (DC.) Stapf. (lemongrass) against Aspergillus 

flavus Link. isolated from stored rice. Letters in Applied Microbiology 37, 86–90. 

Pattnaik, S., Subramanyam, V.R., Kole, C., 1996. Antibacterial antifungal activity of ten essential oils in vitro. 

Microbios 86, 237–246. 

Pattnaik, S., Subramanyam, V.R., Kole, C.R., Sahoo, S., 1995a. Antibacterial activity of essential oils from 

Cymbopogon: Inter- and intra-specific differences. Microbios 84, 239–245. 

Pattnaik, S., Subramanyam, V.R., Rath, C.C., 1995b. Effect of essential oils on the viability and morphology of 

Escherichia coli. Microbios 84, 195–199. 

Pawar, V.C., Thaker, V.S., 2006. In vitro efficacy of 75 essential oils against Aspergillus niger. Mycoses 49, 

316–323. 

Porter, W., 1993. Paradoxical behavior of antioxidants in food and biological systems. In: Williams, G. (Ed.), 

Antioxidants: Chemical, Physiological, Nutritional and Toxicological Aspects, Princeton Scientific, 

Princeton, pp. 93–122. 

Prabuseenivasan, S., Jayakumar, M., Ignacimuthu, S. 2006. In vitro antibacterial activity of some plant essential 

oils. BMC Complementary and Alternative Medicine, 6, 39, doi:10.1186/1472-6882-1186-1139. 

Prashar, A., Hili, P., Veness, R.G., Evans, C.S., 2003. Antimicrobial action of palmarosa oil (Cymbopogon 

martinii) on Saccharomyces cerevisiae. Phytochemistry 63, 569–575. 

Remmal, A., Bouchikhi, T., Rhayour, K., Ettayebi, M., Tantaoui-Elaraki, A., 1993. Improved method for 

the determination of antimicrobial activity of essential oils in agar medium. Journal of Essential Oil 

Research 5, 179–184. 

Rosato, A., Vitali, C., De Laurentis, N., Armenise, D., Antonietta Milillo, M., 2007. Antibacterial effect of some 

essential oils administered alone or in combination with Norfloxacin. Phytomedicine 14, 727–732.


Ruberto, G., Baratta, M.T., 2000. Antioxidant activity of selected essential oil components in two lipid model 

systems. Food Chemistry 69, 167–174. 

Russell, A.D., Hugo, W.B., Ayliffe, G., 1992. Principles and Practice of Disinfection, Preservation and Sterilization. 

2nd ed. Blackwell Science, Oxford. 

Sacchetti, G., Maietti, S., Muzzoli, M., Scaglianti, M., Manfredini, S., Radice, M., Bruni, R., 2005. Comparative 

evaluation of 11 essential oils of different origin as functional antioxidants, antiradicals and antimicrobials 

in foods. Food Chemistry 91, 621–632. 

Shahi, A.K., Tava, A., 1993. Essential oil composition of three cymbopogon species of Indian Thar Desert. 

Journal of Essential Oil Research 5, 639–643. 

Si, W., Gong, J., Tsao, R., Zhou, T., Yu, H., Poppe, C., Johnson, R., Du, Z., 2006. Antimicrobial activity of 

essential oils and structurally related synthetic food additives towards selected pathogenic and beneficial 

gut bacteria. Journal of Applied Microbiology 100, 296–305. 

Singh, G., Paimuthu, P., Murali, H., Bawa, A., 2005. Antioxidative and antibacterial potentials of essential oils 

and extracts isolated from various spice materials. Journal of Food Safety 25, 130–145. 

Southwell, I.A., Hayes, A.J., Marham, J., Leach, D.N., 1993. The search for optimally bioactive Australian tea 

tree oil. Acta Horticulturae 334, 256–265. 

Tampieri, M.P., Galuppi, R., Macchioni, F., Carelle, M., Falcioni, L., Cioni, P., Morelli, I., 2005. The inhibition 

of Candida albicans by selected essential oils and their major components. Mycopathologia 159, 

339–345. 

Tullio, V., Nostro, A., Mandras, N., Dugo, P., Banche, G., Cannatelli, M.A., Cuffini, A.M., Alonzo, V., Carlone, 

N.A., 2007. Antifungal activity of essential oils against filamentous fungi determined by broth microdilution 

and vapour contact methods. Journal of Applied Microbiology 102, 1544–1550. 

van Zyl, R., Seatlholo, S., van Vuuren, S., Viljoen, A.M., 2006. The biological activities of 20 nature identical 

essential oil constituents. Journal of Essential Oil Research 19–133. 

Wang, W., Wu, N., Zu, Y.G., Fu, Y.J., 2008. Antioxidative activity of Rosmarinus officinalis L. essential oil 

compared to its main components. Food Chemistry 108, 1019–1022. 

Wannissorn, B., Jarikasem, S., Siriwangchai, T., Thubthimthed, S., 2005. Antibacterial properties of essential 

oils from Thai medicinal plants. Fitoterapia 76, 233–236. 

Zani, F., Massimo, G., Benvenuti, S., Bianchi, A., Albasini, A., Melegari, M., Vampa, G., Bellotti, A., Mazza, P., 

1991. Studies on the genotoxic properties of essential oils with Bacillus subtilis rec-assay and Salmonella/ 

microsome reversion assay. Planta medica 57, 237–241.

7 Thrombolysis-Accelerating 

Activity of Essential Oils 

contents 


Hiroyuki Sumi and Chieko Yatagai 

7.1 Introduction .......................................................................................................................... 185 

7.2 Test I ..................................................................................................................................... 186 

7.2.1 Results ....................................................................................................................... 186 

7.3 Test II .................................................................................................................................... 186 

7.3.1 Standard Fibrin Plate Method................................................................................... 186 

7.3.2 Euglobulin: Fibrin Plate Method .............................................................................. 186 

7.3.3 Results ....................................................................................................................... 187 

7.4 Test III ................................................................................................................................... 188 

7.4.1 Effects on Tissue Plasminogen Activator (tPA)-Producing Cells ............................. 188 

7.4.2 Platelet Aggregation Test .......................................................................................... 189 

7.4.3 Results ....................................................................................................................... 189 

7.5 Test IV .................................................................................................................................. 189 

7.5.1 In Vivo Fibrinolytic Activity of Euglobulin ............................................................. 189 

7.5.2 Effects on Blood Coagulation Activity ..................................................................... 189 

7.5.3 Results ....................................................................................................................... 189 

7.5.4 Discussion ................................................................................................................. 192 

7.6 Summary .............................................................................................................................. 193 

Acknowledgments .......................................................................................................................... 194 

References ...................................................................................................................................... 194 

We have presented reports that ingestion of various types of alcoholic drinks (Sumi et al. 1988, 

1998) and coffee (Sumi 1997) results in changes in blood coagulation–fibrinolysis systems; in particular, 

a rather lengthy period of promotion of fibrinolysis in the blood was observed with drinking 

of Oturui shochu liquors (distilled only once, retaining the character of the original ingredients and 

known as “authentic” shochu). Studies have been made on properties of the components bringing 

about such effects (Sumi 2003). It has also been generally recognized that essential oils have natural 

healing effects, and the psychological effect of inducing a feeling of relaxation. However, regarding 

the physiological effects of essential oils on blood circulation, especially their direct effects on 

blood coagulation–fibrinolysis systems, no report has yet been presented to our knowledge. 

Lemongrass being a well-known herb, we used the CLT method to check its effects on the 

blood coagulation system and the fibrinolysis system. Lemongrass has the effects of facilitating blood 

coagulation and inhibiting fibrinolysis, but it has been reported that the substantial citral and geraniol 

content in lemongrass contributes to strong inhibitory activity against platelet aggregation, producing 

fibrinolytic effects in vivo as a result. Imai et al. discovered that lemongrass oil, the essential oil 

component (Cymbopogon citrus) of lemongrass (oil yield: 0.2%), shows strong platelet-aggregation 

inhibitory activity (Imai et al. 1986). They reported that, when using platelet-rich plasma of humans, 

185


rabbits, and rats, aggregation through the application of ADP, collagen, and arachidonic acid was 

inhibited by adding lemongrass oil at an amount 1/12,000 of the amount of plasma. It was reported 

that the component of the oil was citral and that trans-citral was more effective than cis-citral. 

In the current study, we conducted tests regarding the effects of more than 100 types of essential 

oils (herbs) on the blood coagulation–fibrinolysis systems, using lemongrass as the control. 

7.2 test I 

Thirty types of essential oils purchased from Holistic Origin Pvt. Ltd. (Singapore) were used. The 

CLT test for essential oils was conducted in the following way: 

Solutions were mixed in a glass test tube (1.0 × 120 mm 2 ). They included 50 μL of a solution of 

each essential oil diluted with dimethyl sulfoxide (DMSO), 250 μL of 0.17 M borate-saline buffer 

with pH 7.8, 500 μL of bovine plasma fibrinogen manufactured by Sigma Co., Ltd. that was dissolved 

in 250 μL of 0.17 borate-saline buffer with pH 7.8 with a concentration of 0.6% and filtered 

with filter paper, and 100 μL of urokinase, a fibrinolytic enzyme in 20 IU/mL of saline. After incubation 

at 37°C for 1 min, 100 μL of bovine thrombin (2.25 IU/mL saline) was added and stirred, 

followed by another incubation. Measurements were then conducted for the time until coagulation 

and until complete lysis of the artificial thrombus (fibrin) were generated, in order to test the blood 

coagulation–fibrinolysis activity of the essential oils (Sumi 2000). 

7.2.1 re s u lt s 

As shown in the left part of Figure 7.1, lysis time was found to be longer for many samples in comparison 

with the control with no additions (broken line), which means that these samples had inhibitory 

effects on coagulation. Each value in the figure is the average value of five repetitions of the test. 

As shown on the right in Figure 7.1, lysis time was seen to be longer for many samples in comparison 

with the control with no additions (broken line), meaning these samples had inhibitory effects on 

fibrinolysis. Overall, there were considerable differences among the aroma essences with regard to 

the blood coagulation–fibrinolysis systems. As shown by the arrows, the results for lemongrass here 

were that it promoted coagulation (index 6/30 = 0.20) and reduced fibrinolysis (24/30 = 0.80). 

7.3 test II 

Essential oils (plant, animal, and synthetic aroma essences) supplied by Kanebo Cosmetics, Inc., 

were used for the test. 

7.3.1 st a n d a r d fib r in Pl at e Me t h o d 

In a round, 90-mm-diameter petri dish, 30 μL of each of the samples, 30 μL of a solution with the 

sample diluted by an equal amount of 10 IU/mL urokinase, and 30 μL of 1% ethanol as the control 

were applied to the artificial thrombus (fibrin) plates, created with 10 mL of fibrinogen solution with 

a final concentration of 0.5% and 0.5 mL of 50 U/mL thrombin. After incubation at 37°C for 4 h, 

the area (mm 2 ) of the lysis area was measured. 

7.3.2 eu G l o b u l i n: fib r in Pl at e Me t h o d 

Citrate blood was drawn from the tail veins of etherized Wistar male rats, and the blood plasma 

obtained through centrifugal separation (3000 rpm, 10 min, room temperature) was diluted 20 times

Thrombolysis-Accelerating Activity of Essential Oils 187 

2.5% Neroli in Jojoba 

2.5% Eucalyptus in Jojoba, 

Eucalyptusglobubus 

2.5% Chamomile in Jojoba, German 

2.5% Chamomile in Jojoba, Roman 

with 0.016% acetic acid. After being left standing for 30 min at 4°C, another centrifugal separation 

(3000 rpm, 5 min, room temperature) resulted in euglobulin fractions, which were dissolved with 

1/15 M phosphate buffer (pH 6.8) containing an amount of 0.9% sodium chloride equivalent to the 

amount of plasma. The euglobulin solution diluted with the same amount of each of the samples, 30 

μL of the mixture was applied to the fibrin plate and after incubation at 37°C for 4 h, the area (mm 2 ) 

of the lysis area was measured. 

7.3.3 re s u lt s 

Citrus bergamia 

Pinus sylvestris 

Pogostemon patchouli 

Boswellia thurifera 

Santalum album 

Cananga odorata 

Vetiveria Aizanoides 

Rosmarinus officinalis 

Origanum marjorana 

Citrus aurantium 

Citratus Lemon 

Lavendula officinalis 

Cupressus sempervirens 

Juniperus virginiana 

Ocimum basiliicum 

Control 

Mentha piperita 

Salvia officinalis 

Thymus vulgaris 

Foeniculum Vulgare 

Commiphora myrrha 

Pelagonium graveolens 

25% Tea Tree in Jojoba, 

Melaleuca alternifolia 

Salvia sclarea 

Juniperus communis 

Cymbapogon Citratus 

2.5% Rose Otto in Jojoba 

0 10 

20 30 40 50 60 

Lysis Time (hr) 

FIgure 7.1 Effects of 30 types of aroma essences on the blood coagulation–fibrinolysis systems. Each 

sample dissolved to a concentration of 20% with DMSO, along with urokinase solution, was added to the 

fibrinogen solution. After adding thrombin solution, measurements were conducted for the time until coagulation 

(left, in minutes) and the time until the lysis of the coagulated fibrin (artificial thrombus). 

Lemongrass resulted in an index of 20/84 = 0.24 for the standard fibrin plate, 23/84 = 0.27 for 

ELT and for CLT, clotting promotion of 65/84 = 0.77 and a fibrinolytic reduction of 40/84 = 0.48. 

In comparison, results of the standard fibrin plate, ELT and CLT tests with the addition of 84 

types of diluted essential oils showed that elder, cashew, and grapefruit have strong fibrinolytic 

activity, whereas celery, fir tree, baca, olive, and rosemary have strong inhibitory effects against 

fibrinolysis.


7.4 test III 

Vetiveria Aizanoides 

Pogostemon patchouli 

Origanum marjorana 

Cymbapogon Citratus 

Rosmarinus officinalis 

Cananga odorata 

Commiphora myrrha 

Mentha piperita 

Lavendula officinalis 

Boswellia thurifera 

Salvia sclarea 

Juniperus virginiana 

Ocimum basiliicum 

Control 

25% Tea Tree in Jojoba, 

Melaleuca alternifolia 

Citratus Lemon 

Pelagonium graveolens 

Foeniculum Vulgare 

Cupressus sempervirens 

Juniperus communis 

Salvia officinalis 

Citrus aurantium 

Santalum album 

Citrus bergamia 

2.5% Chamomile in Jojoba, German 

2.5% Neroli in Jojoba 

2.5% Rose Otto in Jojoba 

2.5% Eucalyptus in Jojoba, 

Eucalyptusglobubus 

2.5% Chamomile in Jojoba, Roman 

FIgure 7.1 (continued). 

Thymus vulgaris 

Pinus sylvestris 

0 5 10 15 20 25 

Lysis Time (min) 

Similarly, 84 types of essential oils were used for this test. Pyrazin, its derivatives of 2-ethyl pyrazine, 

2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine, and 2,6-dimethyl pyrazine and aspirin were 

purchased from Sigma–Aldrich, Inc. 

7.4.1 effeC ts o n ti s s u e Pl asMinoGen aC t iVat o r (tPa)-Pr o d u C i nG Cells 

Tissue plasminogen activator-free human cells were supplied by physiology Assistant Professor 

Yoshida of Miyazaki Medical University. After multiplying these cells using a 24-well microtest 

plate (Falcon) to confluence, the cultured solution inside the wells was removed using an aspirator. 

The cells were then washed twice with PBS(−), 450 μL of a new culture solution and 50 μL of each 

sample were added and incubated for 24 h, following which the culture solution was recovered (first 

medium). After again washing the cells twice with PBS(−), 500 μL of a new culture solution was 

added and incubated again for 24 h, and the culture solution was recovered (second medium). For 

the fibrinolytic activity, the area (mm 2 ) of the lysis area was measured through the standard fibrin 

plate method.


7.4.2 Pl at e l e t aG G r e G at i o n test 

As the aggregation-inducing substance, 22 μL of 300 μM ADP or of 1.2 mg/mL collagen (final 

concentration of 30 μM or 1.2 mg/mL) was added, and the platelet aggregation rate was measured 

for 5 min at 37°C using an aggregometer (PAT-4A: Mebanix). With 100% light transmittance set for 

PPP, platelet aggregation activity was measured. 

7.4.3 re s u lt s 

The effects of lemongrass on tPA-producing cells and platelet aggregation are shown with arrows. 

Regarding the comparative effects of the addition of other essential oils, promotion of tPA was 

observed for orange, basil, and clove (see Figure 7.2). In the case of orange in particular, adding 

450 μL of the cultured solution and 50 μL of the added sample and incubating for 24 h inside a 5% 

CO 2 incubator at 37°C (first medium) showed that, compared with the control, approximately eight 

times the fibrinolytic activity was seen. 

Regarding the effects on platelet aggregation, using ADP as the aggregation-inducing substance 

showed that the inhibitory activity of basil (77%) and tolu (64%) is fairly strong (see Figure 7.3). 

Platelet-aggregation inhibitory activity was also detected in coffee and white peach. The pyradine 

compounds contained in coffee had strong inhibitory effects on platelet aggregation, with strength 

equivalent to that of aspirin in many cases (Table 7.1). 

7.5 test IV 

As in the previous tests, 84 types of essential oils were used for this test. 

7.5.1 in Vi V o fi b r i n o ly t iC aCtiVity o f eu G l o b u l i n 

The aroma essences were diluted 200 times with 0.5% ethanol–0.9% sodium chloride solution, and 

5 mL per kg of body weight (aroma essence volume: 25 μL/kg) was orally administered to Wistar 

male rats using a feeding tube. Blood was drawn from the rat tail veins 1 h prior to oral administration 

and 1 and 2 h after administration. 

For the ELT, 0.1 mL of the blood plasma obtained from citrate blood through centrifugal separation 

(3000 rpm, 10 min, room temperature) was diluted 20 times with 0.016% acetic acid, and left 

standing for 30 min at 4°C. Centrifugal separation (3000 rpm, 5 min, room temperature) resulted 

in euglobulin fractions, which were dissolved with 0.1 mL of 0.1 M tris-hydrochloric acid buffer 

(pH 7.4) to obtain the sample. 90 μL of the euglobulin solution and 10 μL of 100 U/mL thrombin 

were mixed inside a 96-well microtest plate and incubated at 37°C, following which turbidity 

of the dissolving thrombi was measured every 10 min at 405 nm using a Well reader (SK601: 

Seikagaku Corp.). 

7.5.2 effeC ts o n bl o o d Co a G u l at i o n aCtiVity 

For the measurements, Data-Fi aPTT (Dade Behring) was used for the activated partial thromboplastin 

time (aPTT), and thromboplastin C plus (Dade Behring) was used for the prothrombin time (PT). 

All the animals used in the tests were healthy and all provisions of the Declaration of Helsinki 

(1964) were met. 

7.5.3 re s u lt s 

Finally, several essential oils were orally administered to rats and changes in their blood were 

tested for through ELT. For mainly coffee and lemongrass, the reduction of ELT was observed,


Lemongrass 

Almond 

Angelica 

Artemisia 1 

Artemisia 2 

B.Megastigma 

Baka 

Balsamic 

Basil 

Cacao beans 

Cachute 

Cafe 

Camomile 

Cardamon 

Carnation 

Carrot 

Celery 

Citronellol 

Clove 

Coconuts 

Coffee 

Coriander 

Crocus 

Curry 

Elder 

Fir tree 

Fusel oil 

Galbanum 

Geraniol 

Ginger 

Grape fruits 

Helichrysum 

Herb 1 

Herb 2 

Hibiscus 

Immortelle 

Ionon A 

Ionon B 

Isopropanol 

Jatamansi 

Lemongrass 

a b c d e f g h 

a b c d e f g h 

Zymography of the conditioned media 

by HeLa S3 cells in the presence of 

aroma essences 

Loading sample was 20 µ l, and 

incubation time was 24 hrs. at 37°C. 

I: first medium, II: second medium. 

(a) Clove, (b) Violet-like synthetic 

aroma 1, (c) Resin 2, (d) Basil, (e) 0.1% 

EtOH, (f) Milli Q, (g) 2 IU/ml tPA, 

(h) 1 IU/ml UK. 

Jonquil 

Juniper 

Lacton synthetic aroma 

Lavender 

Linalool 

Lycoris 

Musklike synthetic aroma 

Nerol 

Niaouli 

Nigelle 

Olibanum 

Olive 

Opoponax 

Orange 

Parsley 

Pepper 

Pistacia 

Porto 

Reglis 

Resin 1 

Resin 2 

Resin 3 

Riz 

Rose 

Rosemary 1 

Rosemary 2 

Rovensara 

Rum 

Sage 1 

Sage D 

Sage S 

Shobu 

Synthetic aroma 

α-Terpineol 

Tolu 

Valerian 

Violetlike synthetic aroma 1 




Whisky 

White peach 1 

White peach 2 

Yuzu 

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 

Ratio (sample/0.1% EtOH) 

FIgure 7.2 tPA activity generated through cultivation of tissue plasminogen activator-free cells. Further 

isolation of each activity through zymography possible (partial results shown). Average values (n = 3) shown; 

■: first medium, □: second medium.


Lemon grass 

Almond 

Angelica 

Artemisia 1 

Artemisia 2 

B.Megastigma 

Baka 

Balsamic 

Basil 

Cacao beans 

Cachute 

Cafe 

Camomile 

Cardamon 

Carnation 

Carrot 

Celery 

Citronellol 

Clove 

Coconuts 

Coffee 

Coriander 

Crocus 

Curry 

Elder 

Fir tree 

Fusel oil 

Galbanum 

Geraniol 

Ginger 

Grape fruits 

Helichrysum 

Herb 1 

Herb 2 

Hibiscus 

Immortelle 

Ionon A 

Ionon B 

Isopropanol 

Jatamansi 

Jonquil 

Juniper 

Lacton synthetic aroma 

Lavender 

Linalool 

Lycoris 

Musklike synthetic aroma 

Nerol 

Niaouli 

Nigelle 

Olibanum 

Olive 

Opoponax 

Orange 

Parsley 

Pepper 

Pistacia 

Porto 

Reglis 

Resin 1 

Resin 2 

Resin 3 

Riz 

Rose 

Rosemary 1 

Rosemary 2 

Rovensara 

Rum 

Sage 1 

Sage D 

Sage S 

Shobu 

Synthetic aroma 

α-Terpineol 

Tolu 

Valerian 





Whisky 

White peach 1 

White peach 2 

Yuzu 

Lemongrass 

Right Transmission(%) 

0 10 

20 30 40 50 60 70 80 90 

Inhibition (%) 

Incubation Time (min) 

4 3 

Inhibitory effect of aroma essences on ADP aducted 

platelet aggregation. 

Platelet aggregation was inhibited after preincubation 

of 50 µl rat-PRP, 100 µl Tyrode buffer and aroma 

essences for 5 min at 37°C. Final concentration of ADP 

in the reaction mixture was 30 µM. For determination, 

aggregometer PAT-4A was used with continuous stirring 

at 1000 rpm. 

1 : Basil, 2 : Whisky, 3 : Juniper, 4 : Control 

(0.225% EtOH) 

FIgure 7.3 Effects of essential oils on platelet aggregation activity. For rat blood platelets, 30 μM ADP 

used as aggregation-inducing substance. Aggregation patterns from aggregometer shown. Average values 

(n = 3) shown. 

1 

2


table 7.1 

antiplatelet aggregation effects of Pyradine compounds 

Pyridine 

2-ethyl 

pyridine 

2,5-dimethyl 

pyridine 

2,3,5-trimethyl 

pyridine 

2,6-dimethyl- 

3-methyl 

pyridine 

Aspirin 

H 3 C 

H3 C 

H 3 C 

meaning a tendency to promote fibrinolysis (Figure 7.4). The aPTT (38 ± 7 s) and PT (12 ± 3 s) 

values as a result of the effects of coffee and lemongrass were investigated, but the changes were 

not significant. 

7.5.4 di sC u s s i o n 

components aggregation 50 mg/ml 5 mg/ml 1 mg/ml 0.5 mg/ml 

N 

N 

COOH 

N 

N 

N 

N 

N 

N 

N 

N 

C 2 H 5 

CH 3 

CH 3 

CH 3 

CH 3 

CH 3 

OOCCH 3 

Collagen ||| || | — 

ADP ||| || | — 

Collagen ||| ||| || — 

ADP ||| ||| ||| | 

Collagen ||| ||| | — 

ADP ||| ||| — — 

Collagen ||| ||| — — 

ADP ||| ||| ||| | 

Collagen ||| ||| — — 

ADP ||| || | — 

Collagen ||| ||| | — 

ADP ||| ||| || — 

Note: In the order of the strength of platelet aggregation, reactions as viewed with the naked eye are shown. 

Various tests related to the blood coagulation–fibrinolysis systems were conducted using essential 

oils I and II, but the results were not consistent. However, it seemed that there were effects on the 

promotion of tPA from vascular endothelial cells and on platelets, and a fibrinolytic tendency was 

observed in the test using lemongrass cells. In the case of coffee, it seemed that there were effects 

of the activity of pyridine compounds in promoting fibrinolysis. Yamamoto (2003) selected 6 out of


ELT(min) 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

26 types of herbs for their blood fluidity, through a test in which each herb (aroma essence) was 

added to blood and fluidity of the blood was measured. The six types selected were echinacea, 

thyme, hip, marigold, lavender, and lemongrass. 

The primary purpose of aroma therapy using essential oils is deemed to be bringing about relaxation, 

but many essential oils have antibacterial activity and are effective in the sterilization of skin. 

Takarada et al. (2004) used manuka oil and rosemary oil to compare and study their antibacterial 

activities against bacteria in the mouth, which cause dental caries and periodontitis. Many applications 

have recently been filed for patents related to lemongrass. Examples include a stress reliever 

(Suntory Ltd. 2003) containing aromatic components of alcoholic drinks as effective components, 

bath tablets (Cosme Park 2005) containing herb ingredients, fragrances (Nitto Pharmaceutical 

2005) containing 0.1%–5% lemongrass oil per weight, and an aroma essence for increasing memory 

(Pola Chemical Industries 2001). 

If practical effects can be achieved merely by smelling aroma essences rather than ingesting 

them, it is possible that aromatic components may constitute a wholly new category of functional 

materials. In tests adding aromatic components using sweet potato-based shochu liquor, we have 

already shown that the amount of fibrinolytic enzymes produced from human vascular endothelial 

cells increases (Sumi et al. 2001). It has also been reported that many aroma essences are generated 

at the time of heating and distilling unprocessed shochu liquor for Otsurui shochu liquors, particularly 

sweet potato-based shochu liquors (Ota 1991). A more detailed analysis of each essential 

oil and identification of the in vivo effects of each essential oil would be issues to address from 

now on. 

7.6 summary 

Control 

(0.5% EtOH) 

Lemongrass Baca Clove Coffee Rosemary 1 

FIgure 7.4 Oral administration. Changes in the blood caused by oral administration of several essential 

oils as measured by plasma ELT. Values are means ± SE (n = 4); ■, 1 h before administration; □, 1 h after 

administration; , 2 h after administration. 

Tests conducted on more than 100 types of essential oils showed that some of them had fibrinolytic 

activity similar to lemongrass. However, no correlation was found among the results of the standard 

fibrin plate, ELT, and CLT methods. It is thought that promoting the release of tissue plasminogen 

activators from cells and inhibiting platelet aggregation are significant reactions, which were 

revealed to be the result of complex configurations.


acKnoWledgments 

We are grateful to Mr. S. Murakami for excellent technical assistance. Essential oils were kindly 

supplied by Kanebo Cosmetics, Inc. (Kanagawa). 

reFerences 

Cosme Park. 2005. Bath tablets, Published Patent Application 112794 (in Japanese). 

Imai H, Tamada T, Sawai Y, Yoshida M, Takao K, Endo E, Ohshiba S, Kojisawa Y. 1986. Blood platelet 

aggregation inhibitory activity of lemongrass oil. 28th Convention of the Japanese Society of Clinical 

Hematology, Extracts, 279 (in Japanese). 

Nitto Pharmaceutical Industries Ltd. 2005. Fragrances, Published Patent Application 023044 (in Japanese). 

Ota T. 1991. Aroma of sweet potato-based shochu liquor, Tokyo 86: 250–254 (in Japanese). 

Pola Chemical Industries Inc. 2001. Aroma essences and components containing aroma essences for increasing 

memory, Published Patent Application 288493 (in Japanese). 

Sumi H, Hamada H, Tsushima H, Mihara H. 1988. Urokinase-like plasminogen activator increased in plasma 

after alcohol drinking. Alcohol Alcoholism 23: 33–43. 

Sumi H, Iijima Y, Komine S, Sasahira T. 2001. Kagoshima Industry Support Center, Report on Commissioned 

Research and Development Project 2000: 1–6. 

Sumi H. 1997. Abnormalities in the blood coagulation and fibrinolysis systems. Nippon Rinsho 712: 233–239 

(in Japanese). 

Sumi H. 2000. Blood circulation: Analysis of foods and aroma essences related to blood coagulation– 

fibrinolysis systems. Food Technology 20: 64–70 (in Japanese). 

Sumi H. 2003. Improvements in blood circulation and disease prevention by food components, Food Style 

21(7): 47–53 (in Japanese). 

Sumi H, Kozaki Y, Yatagai C, Hamada H. 1998. Effects of wine on plasma fibrinolytic and coagulation systems. 

Japanese Journal of Alcohol Studies and Drug Dependence 33: 263–272. 

Suntory Ltd. 2003. Stress reliever, Published Patent Application 171286 (in Japanese). 

Takarada K, Kimizuka R, Takahashi N, Honma K, Okuda K, Kato T. 2004. A comparison of the antibacterial 

efficacies of essential oils against oral pathogens. Oral Microbiology and Immunology 19(1): 61–64. 

Yamamoto N. 2003. Effects of herbs on blood fluidity. Food Style 21: 61–63 (in Japanese).

8 

contents 


Analytical Methods 

for Cymbopogon Oils 

Ange Bighelli and Joseph Casanova 

8.1 Introduction .......................................................................................................................... 195 

8.2 Methods for EO Analysis: A Summary ................................................................................ 196 

8.2.1 Chemical Methods and Fractional Distillation......................................................... 196 

8.2.2 Chromatographic Techniques ................................................................................... 197 

8.2.2.1 Thin-Layer Chromatography (TLC) .......................................................... 197 

8.2.2.2 Gas Chromatography ................................................................................. 197 

8.2.3 Hyphenated Techniques ............................................................................................ 198 

8.2.3.1 GC-MS and GC-MS Combined with GC(RI) ........................................... 198 

8.2.3.2 GC×GC-MS ............................................................................................... 199 

8.2.3.3 GC-MS-MS ................................................................................................ 199 

8.2.3.4 GC-FTIR, GC-MS-FTIR ...........................................................................200 

8.2.3.5 HPLC-MS, HPLC- 1 H NMR, and HPLC-GC-MS .....................................200 

8.2.3.6 Essential Oil Analysis by 13 C NMR ..........................................................200 

8.2.3.7 Enantiomeric Differentiation ..................................................................... 201 

8.2.3.8 Two-Step Procedure ...................................................................................202 

8.3 Analysis of Cymbopogon Oils ..............................................................................................203 

8.3.1 Earliest Studies: Analysis by Chemical Methods (Isolation of Compounds and 

Miscellaneous Methods) ...........................................................................................204 

8.3.2 Analysis by Chromatographic Techniques [TLC, HPLC, GC(RT) or GC(RI)] ......205 

8.3.3 Analysis by Mass Spectrometry Coupled with Gas Chromatography .....................206 

8.3.4 Combined Analysis by Chromatographic and Spectroscopic Techniques: TLC, 

CC, GC(RT) or GC(RI) and GC-MS .......................................................................206 

8.3.4.1 Cymbopogon Oils of Commercial Interest ................................................207 

8.3.5 Other Cymbopogon Oils ...........................................................................................209 

8.3.6 Enantiomeric Differentiation by Chiral GC ............................................................. 210 

8.3.7 Combined Analysis of Cymbopogon Oils by Various Techniques: TLC, CC, 

IR, GC(RI), GC-MS, and 13 C NMR ......................................................................... 211 

8.3.8 Analysis of C. Giganteus Oil: A Summary of Analytical Methods Involved in 

the Analysis of Cymbopogon Oils ............................................................................ 212 

8.4 Conclusion ............................................................................................................................ 215 

Acknowledgments .......................................................................................................................... 215 

References ...................................................................................................................................... 215 

The Cymbopogon genus comprises 56 species, and most of them produce essential oil (EO) by 

hydrodistillation or steam distillation of aerial parts. Various Cymbopogon species, such as C. nardus 

(L.) Rendle, C. winterianus Jowitt, C. citratus Stapf, C. flexuosus Stapf and C. martinii (Roxb.) 

195


Wats., are well known as sources of commercially valuable compounds such as geraniol, geranyl 

acetate, citral (neral and geranial), and citronellal (Surburg and Panten 2006). The other species 

contribute to the conservation of the biodiversity through the world. 

EOs, which are the raw materials used in the perfume, fragrance, and flavor industries, are, in 

general, complex mixtures of more than 100 individual components, containing mainly monoterpenes 

and sesquiterpenes that present various frameworks and functions. The identification of these 

compounds would be carried out using various techniques. Obviously, the choice of the analytical 

methods depends on whether the final objective is structural identification of an unknown substance 

or recognition of a substance that has already been identified. 

In this chapter, we first summarize the analytical methods developed for identification of individual 

components of EOs; then we apply these techniques and methods to the analysis of Cymbopogon 

EOs, including studies carried out in our laboratories using a combination of various analytical 

techniques. 

8.2 methods For eo analysIs: a summary 

Identification of the individual components of an EO is a difficult task that first requires an adequate 

choice of analytical technique and then a careful utilization of the instruments, software, spectral 

data libraries and, sometimes, statistical tools. 

Depending on the objective of analysis (routine, quality control, detailed analysis of an EO investigated 

for the first time, etc.) and the complexity of the mixture (number and structure of the components 

and heat sensitivity), various schemes can be drawn up. 

In routine analysis, identification of a component was achieved by combination of “on-line” 

chromatographic separation and spectroscopic identification. For instance, a fast-scanning mass 

spectrometer directly coupled with a gas chromatograph is the basic equipment of control in the 

field of EO analysis. Nevertheless, misuse—or abuse—of modern instrumentation is not unknown. 

Nowadays, a conventional analysis of an EO is carried out by matching against computerized mass 

spectral libraries and comparison of the retention indices with those of authentic samples (GC[RI] 

and GC-MS). However, more sophisticated techniques are needed for the analysis of EOs, and 

a wide variety of combinations of analytical techniques are being developed, including complex 

hybrids such as GC-MS-FTIR, HPLC-GC-MS, or HPLC- 1 H NMR. In a similar fashion, individual 

components of an EO may be identified by comparison of the chemical shift values in the 13 C NMR 

spectrum of the mixture with those of reference compounds. 

Despite the improvement of these on-line analytical techniques, the misidentification of some 

compounds, especially sesquiterpenes, still occurs. For this reason, several research groups developed 

a two-step procedure in which a small quantity of a substance is separated by a chromatographic 

technique and then identified by comparison of its spectral data, including 1 H NMR and 

sometimes 13 C NMR, with those of reference compounds. This “off-line” sequence is obviously 

more accurate but very time consuming. 

Nowadays, in numerous research laboratories, the chemical composition of complex EOs is analyzed 

by combination of various techniques, the oil being prefractionated by fractional distillation 

and/or column chromatography and, eventually, by HPLC or preparative gas chromatography (PGC). 

Prefractionation of the EO considerably reduces the number of coeluted compounds. Then, analysis of 

the fractions is achieved by combination of spectroscopic techniques, such as MS, IR, and/or NMR. 

8.2.1 Ch e M iC a l Me t h o d s a n d fr a C t i o n a l distill ation 

The procedures that were mostly used during the last century for the isolation of EO constituents 

were chemical methods and fractional distillation. Concerning chemical methods, a preparative 

separation of an EO into different groups of components was achieved. In this procedure, the 

oil was successively treated by aqueous sodium carbonate (5%), aqueous sodium hydroxide (5%),

Analytical Methods for Cymbopogon Oils 197 

methanolic sodium hydroxide (0.5N), sodium hydrogen sulfite or Girard reagent and phthalic anhydride 

to separate various families of compounds: acids, phenols, esters and lactones, aldehydes 

and ketones, and alcohols (primary and secondary). Esters and lactones can be hydrolyzed, and the 

resulting acids separated as salts. The final residue, consisting of tertiary alcohols, ethers, and hydrocarbons, 

must be separated by physical methods such as fractional distillation, crystallization, or 

liquid–liquid extraction (on the basis of the difference of solubility of the components in various 

solvents) (Kubeczka 1985). 

Fractional distillation had an important role in the preparative isolation of EO constituents, 

although it is seldom possible to obtain chemically pure components by this technique. The development 

of efficient distillation columns (spinning-band columns) enables one to fractionate milliliter 

amounts of EOs under mild conditions. For instance, by using a so-called Spaltrohr column, 

amounts of a few milliliters may be distilled at reduced pressure, which allows the distillation 

of thermally unstable components. With this type of column, up to 100 theoretical plates may 

be achieved. The efficiency of this device is clearly demonstrated by the separation of citronellyl 

acetate and geranyl acetate (boiling points at 1 mbar: 73.5°C and 77.0°C, respectively). However, 

pure compounds from EOs are rarely obtained by fractional distillation since isomerization and 

decomposition of labile components occasionally take place (Kubeczka, 1985). 

8.2.2 Ch r o M at o G r a P h iC te C h n i q u e s 

8.2.2.1 thin-layer chromatography (tlc) 

Thin-layer chromatography is a type of liquid chromatography that can separate different chemical 

compounds based on the rate at which they move through a support under defined conditions. 

The support, known as the plate, is a layer of support material (silica gel or alumina) that has been 

spread out and dried on a sheet of material such as glass. The mobile phase is a solvent or a mixture 

of solvents. Individual components of a mixture are identified after separation by migration, by 

comparison of their Rf values with those of reference compounds obtained under the same experimental 

conditions. Due to its simplicity and speed, TLC was an important pioneering method in the 

analysis of EOs (Kubeczka 1985; Rouessac and Rouessac 1994). 

TLC can also be used for preparative separation. By means of plates up to 1 m long and a layer 

thickness up to 2 mm, several grams of a mixture of compounds can be applied as a line. The various 

bands are scraped off, collected, and the components eluted with appropriate solvents. 

8.2.2.2 gas chromatography 

Gas chromatography (GC), which allows the separation of volatile compounds from complex mixtures 

as well as their quantification, has become one of the most important tools in the analysis of 

EOs (Kubeczka, 1985). Nowadays, the development of efficient capillary columns allows the individualization 

of several hundreds of components. For instance, more than 200 compounds have been 

distinguished in the chromatogram of labdanum oil (Cistus ladanifer oil) or vetiver oil (Weyerstahl 

et al. 1998, 2000). Concerning the identification of individual components, the comparison of their 

retention times with those of reference compounds is generally not sufficient, even using two columns 

of different polarity. For that reason, utilization of retention indices is generally preferred. 

Retention indices are determined relative to the retention times of a series of n-alkanes with constant 

temperature (Kováts indices [KIs]) (Kováts 1965) or with linear temperature programmed 

(retention indices [RIs]) (Van Den Dool and Kratz 1963). Identification is then carried out by comparison 

of retention indices with those of authentic compounds or literature data (Figure 8.1). 

However, identifying sesquiterpenes (or diterpenes) by comparison of their RIs remains a difficult 

task. Indeed, as mentioned by Joulain (1994), more than 230 natural sesquiterpenes, which possess 

a molecular mass of 204, have been reported, and the values of their GC RIs differ by less than 

30 points. Moreover, RI values reported in the literature for the same compound can vary by more


GC-MS 

Chromatogram 

Mass spectrum 

Computer program 

Mass spectra libraries 

(Joulain, Nist, Wiley) 

• Comparison with 

reference spectra 

• Structure proposal 

than 10 points, particularly those concerning the polar column (Grundschober 1991). Consequently, 

identification of all the components of a complex EO using only GC appeared very difficult, if not 

impossible, for sesquiterpenes, even by taking into account their RIs on polar and apolar columns. 

8.2.3 hy P h e n at e d te C h n i q u e s 

ESSENTIAL OIL 

GC(RI) 

Chromatogram (apolar and 

polar columns) 

RI apolar 

RI polar 

Reference Indices 

RIs apolar 

RIs polar 

Comparison with 

RIs of reference 

compounds 

Identification of individual components 

13 C NMR 

Essential oil spectrum 

Computer program 

Spectral data libraries 

• «Laboratory» library 

• «Literature» library 

• Number of observed signals 

• Number of overlaped signals 

• Chemical shift variations 

FIgure 8.1 Combined analysis of essential oils by GC-MS, GC(RI) and 13 C NMR. 

8.2.3.1 gc-ms and gc-ms combined with gc(rI) 

A fast-scanning mass spectrometer using electronic impact (EI) mode, directly coupled with a gas 

chromatograph (GC-MS), is the basic equipment of control in the field of EO analysis. The two 

most-used analyzers in this field are the quadrupole and ion-trap types. Identification of the components 

in the oil is achieved by computer matching with laboratory-made or commercial mass spectral 

libraries containing several thousands spectra (Figure 8.1). Among the best-known commercial 

computerized libraries, we could mention the Wiley Registry of Mass Spectral Data (McLafferty 

and Stauffer 1994), the National Institute of Standards and Technology EPA/NIH Mass Spectral 

Library (NIST 1999), and the Terpenoids and Related Constituents of Essential Oils library (König 

et al. 2001). Comparison of experimental spectra may be done with those of literature data compiled 

in various paper libraries published, among others, by McLafferty and Stauffer (1988), Joulain


and König (1998), and Adams (2007). Better reliability is generally obtained when comparing the 

experimental spectra with those of reference compounds recorded in the laboratory with the same 

experimental conditions. 

Analysis of EOs by GC-MS began in the 1960s and was applied to common EOs of commercial 

interest. However, it is quite difficult to avoid misidentification of some compounds, especially those 

that possess insufficiently differentiated mass spectra. This problem concerns not only epimers 

such as α-cedrene and α-funebrene, stereoisomers such as (Z)-β-farnesene and (E)-β-farnesene, or 

diastereoisomers such as α-bisabolol and α-epi-bisabolol, but also compounds with different skeletons, 

such as (E,Z)-α-farnesene (linear sesquiterpene) and cis-α-bergamotene (bicyclic sesquiterpene) 

(Schultze et al. 1992), or 1-endo-bourbanol (tricyclic sesquiterpene) and 1,6- germacradien-5-ol 

(monocyclic sesquiterpene) (Joulain and Laurent 1989). 

For that reason, and although analyses by GC-MS are unfortunately still reported in the literature, 

identification of a component is much more accurate when GC-MS is used in combination with 

GC(RI) (Figure 8.1). Today, it is considered by specialized reviews that analysis of an EO by at least 

two techniques, for instance, MS in combination with RIs measured on two columns of different 

polarity, should be done to make the work publishable. 

Vernin et al. (1986, 1990) developed a computerized procedure based on the combination of 

mass spectral data and retention index on polar and apolar columns to identify the individual components 

of several EOs. Cavaleiro (2001) used the same procedure for the characterization of several 

Juniperus EOs. 

In some cases, positive or negative chemical ionization mass spectrometry [(PCI)MS or (NCI) 

MS] allows the identification of compounds that possess similar mass spectra. Chemical ionization 

produces mass spectra that exhibit “quasi-molecular” ions from which the molecular mass of the 

compounds can be easily deducted; that is not always possible using EI. As in the case of EI mode, 

the quadrupole or ion-trap analyzer can be used in the chemical ionization mode. Utilization of 

(CI)MS allowed the differentiation of alcohols, such as the four isomers of isopulegol (Lange and 

Schultze 1988a), or esters (Lange and Schultze 1988b), whereas the mass spectra of these compounds 

are generally similar when EI mode is used. In the same way, several isomers bearing the 

pinane skeleton (α-pinene, β-pinene, and cis-δ-pinene; pinocamphone and isopinocamphone; nopinone 

and isonopinone) were differentiated by (PCI)MS by using ammoniac as reactive gas (Badjah 

Hadj et al. 1988). The choice of the reactive gas (methane, isobutene, or ammoniac for PCI and a 

mixture of N 2O and methane or ammoniac for NCI) to differentiate some isomers depends on the 

structure and the functionalization of the molecules under consideration. For instance, GC-(CI) 

MS with isobutane and ammonia chemical ionization allowed the distinguishing of sesquiterpene 

hydrocarbons (Schultze et al. 1992). (PCI)MS and (NCI)MS proved to be useful for the analysis 

of complex EOs (Paolini et al. 2005). However, due to the difficulty of obtaining reproducible spectra, 

chemical ionization mass spectrometry is not usable as unique technique, but it is recommended 

in combination with GC-(EI)MS for the analysis of complex EOs. 

8.2.3.2 gc×gc-ms 

In some very complex mixtures in which the low peak resolution in GC prevents good characterization, 

the use of two-dimensional GC (GC×GC) can be useful to improve the resolution (Dugo et al. 

2000). For instance, using this two-dimensional technique, Mondello et al. (2005) eluted separately 

β-bisabolene, neryl acetate, and bicyclogermacrene in an EO of citrus, these three compounds being 

coeluted by conventional GC. 

8.2.3.3 gc-ms-ms 

Combination of GC and 2D mass spectrometry (GC-MS-MS) has been used for the analysis of complex 

EOs. For instance, Decouzon et al. (1990) clearly identified the four stereoisomers of dihydrocarveol 

using MS-MS (NCI) by observation of some characteristic fragments, which is not possible


by monodimensional mass spectrometry [(NCI)MS]. Cazaussus et al. (1988) identified khusimone, 

a particular sesquiterpene, by GC-MS-MS in EI mode, in the oxygenated fraction of a complex 

vetiver EO that contained more than 100 components. 

8.2.3.4 gc-FtIr, gc-ms-FtIr 

The improvement of the threshold of detection of FTIR in the last decade allowed the development 

of this on-line technique for the analysis of various families of organic compounds (Coleman et al. 

1989). Concerning EO components, GC-FTIR is particularly well suited to identifying compounds 

that possess insufficiently differentiated mass spectra. For instance, this technique has been used 

to identify two sesquiterpene alcohols, 1-endo-bourbanol (tricyclic) and 1,6-germacradien-5-ol 

(monocyclic) (Joulain and Laurent 1989), on the basis of their infrared mass spectra combined with 

their RIs. CG-FTIR is also well suited for analysis of compounds that suffer rearrangement in MS, 

such as germacrene-B and bicyclogermacrene, correctly identified by this method in citrus EOs 

(Chamblee et al. 1997). Conversely, it has been also reported that GC-FTIR was not appropriate to 

distinguish β-gurjunene and cis-1,3-dimethylcyclohexane, two compounds that possess quite different 

structure (Hedges and Wilkins 1991). 

It seems that GC-FTIR is not really appropriate for the analysis of EOs, but it provides useful 

information when utilized in combination with GC-MS. For that reason, hyphenated techniques 

such as GC-FTIR-MS have been developed and successfully used in the field of EOs. For example, 

Hedges and Wilkins (1991) identified, by GC-FTIR-MS, 26 minor components together with 

the main compound, 1,8-cineole, in an EO from Eucalyptus australiana. A better separation of the 

components was obtained when multidimensional GC is directly combined with FTIR and MS for 

analysis of eucalyptus EOs (Krock et al. 1994). 

8.2.3.5 hPlc-ms, hPlc- 1 h nmr, and hPlc-gc-ms 

Some EOs contain a variable amount of poor volatile compounds. Their analysis can be carried out 

by HPLC directly coupled with MS. Utilization of these combined techniques allowed the identification 

of oxygen heterocyclic compounds, coumarins, psoralenes, and flavones in citrus EOs (Dugo 

et al. 2000). 

More recently, HPLC has also been combined with 1 H NMR, which provides important structural 

information. Two methods can be used: (1) stopped flow, in which the elution is stopped to 

record the spectra of a component, and (2) continuous flow, in which the spectra of a component 

is recorded during the elution of the liquid. Today, the use of high-field spectrometers (up to 21 T) 

allows one to record spectra of pure compounds with a quantity near to 1 ng (Korhammer and 

Bernreuther 1996). 

Even though HPLC- 1 H NMR is mainly used in the pharmaceutical industry, it was also regularly 

used to identify some terpenes such as three sesquiterpene lactones present in a solvent extract of 

Zaluzania grayana (Spring et al. 1995). 

With the aim of limiting the number of coeluted compounds that can occur in complex EOs, 

HPLC was combined with another chromatographic technique such as GC before spectroscopic 

identification. This method (HPLC-GC-MS) has been used to identify very minor compounds in 

citrus EOs (Mondelo et al. 1995, 1996). 

8.2.3.6 essential oil analysis by 13 c nmr 

Since its discovery, NMR has been a powerful tool for structure elucidation of organic molecules. 

Even 1 H NMR spectra recorded with low field spectrometers provided structural information not 

available with other techniques at that time. The introduction of high-field spectrometers, combined 

with the discovery of Fourier Transform NMR and two- and three-dimensional NMR (2D and 3D 

NMR), made the use of that technique essential in structure elucidation of natural compounds isolated 

from plants (Derome 1987).


Concerning the analysis of natural mixtures, the chief idea was to take benefit of the information 

provided by 13 C NMR, avoiding, or at least limiting as far as possible, the separation steps. 

Carbon-13 is preferred to proton, despite its low natural isotopic abundance (1.1%), for several 

reasons: 

1. Carbon constitutes the backbone of organic molecules, and the slightest structural modification 

induces measurable chemical shift variations. 

2. The sweep width, around 240 ppm, is much wider than that of protons, leading to a better 

spectral dispersion. 

3. 13 C NMR spectra can easily be simplified by complete decoupling of protons, so that each 

signal appears as a singlet. 

4. Transverse relaxation time, T 2, is higher than that of the proton, leading a better resolution. 

5. To avoid any thermal degradation, spectra were recorded at room temperature. Furthermore, 

the sample may be recovered and then submitted to other spectroscopic analyses. 

In their pioneering work, Formácek and Kubeczka (1982a,b) used 13 C NMR, in combination with 

GC, to confirm the occurrence of a compound previously identified (or suspected) by GC. Since that 

time, 13 C NMR has been regularly employed, in various laboratories, to contribute to the analysis of 

EOs (De Medici et al. 1992; Alencar et al. 1997; Ramidi et al. 1998; Ahmad and Jassbi 1999; Núñez 

and Roque 1999; Ferreira et al. 2001a, 2001b; Al-Burtamani et al. 2005). A computerized procedure 

has been proposed by Ferreira et al. (2001a, 2001b). 

In 1992, our group developed a computerized method, based on the analysis of the 13 C NMR 

spectrum, that allows the direct identification of the (major) components of a mixture (Corticchiato 

and Casanova 1992; Tomi et al. 1995). 

In that procedure, there is neither separation nor individualization of the components before 

their identification. The computer program, made up in our laboratories from Microsoft Access, 

compared the chemical shift of each carbon in the experimental spectrum with the spectra of pure 

compounds listed in our spectral libraries (Figure 8.1). Each compound is then identified, taking 

into account three parameters that are directly available from the computer program: 

1. The number of observed carbons with respect to the number of expected signals 

2. The number of overlapped signals of carbons that possess the same chemical shift 

3. The difference of the chemical shift of each signal in the mixture spectrum and in the 

reference spectra 

Two complementary spectral data libraries were created, the first one containing spectra of mono-, sesqui-, 

and diterpenes, and phenylpropanoids recorded in our laboratories under the same experimental 

conditions (solvent, concentration, pulse sequence). The reference compounds were commercially available 

or isolated from essential oils and extracts. The second library was constructed with literature data. 

Quantitative determination of some components may be carried out by NMR when necessary 

(nonvolatile compounds, thermolabile compounds) (Rezzi et al. 2002; Baldovini et al. 2001). 

Analysis of complex EOs may be achieved by a combination of CC and 13 C NMR (Gonny et al. 

2004; Blanc et al. 2006). 

Our results have been reviewed (Bradesi et al. 1996; Tomi and Casanova 2000) with a special 

insight into the application of NMR to the analysis of EOs from Labiatae (Tomi and Casanova 

2006). 

8.2.3.7 enantiomeric differentiation 

EOs contain mainly terpenes that are present in pure enantiomeric form or as a nonracemic mixture 

of both enantiomers. This point is quite important since olfactory characteristics of a terpene 

are generally different, depending on the considered enantiomer. For instance, (R)-(+)-limonene


smells like orange, while the (S)-(−)-enantiomer smells like turpentine. (−)-Menthol smells and 

tastes sweetish-minty and is fresh and strongly cooling, in contrast to the (+)-enantiomer, which 

smells and tastes herby-minty and is weakly cooling. (S)-(+)-Carvone possess the typical odor of 

caraway, and its (R)-(−)-enantiomer smells more like peppermint (Bretmaier 2006). 

Moreover, in an aromatic plant, the two enantiomers of a compound usually have different origin. 

For instance, (+)-limonene is the major component of orange zest oil, whereas (−)-limonene 

is characteristic of eucalyptus, mint, or pine oils (Mosandl 1988). Coriander oil contains mainly 

(+)-linalool, whereas (−)-linalool is present in basil oil (Boelens et al. 1993). 

Therefore, measurement of enantiomeric excess of selected terpenes in EOs is an important 

parameter for the characterization of a plant as well as for quality control. For example, the presence 

of pure (+)-fenchone in fennel EO indicates the natural origin of this oil. Conversely, (−)-fenchone 

is present only in Artemisia and cedar oils (Ravid et al. 1992). 

The enantiomeric differentiation of monoterpenes and monoterpenoids, and the quantitative 

determination of the enantiomers, is typically carried out using a chiral GC column. Permethylated 

cyclodextrins are the most commonly used chiral phases as they are efficient for many terpenoids 

present in various EOs (Bicchi et al. 1997, 1999). 

Using a single chiral column is not recommended since the enantiomeric differentiation of most 

components of the oil induces an increase of the number of peaks in the chromatogram and, consequently, 

the number of coelution. So, it is not easy to attribute the right peak to one enantiomer of a 

compound. In such a case, GC needs to be coupled with MS. 

Two-dimensional GC is preferred. The components of the oil are first separated on a nonchiral 

column contained in the first oven of the chromatograph and, then, only some compounds (selected 

with respect to their retention time and order of elution) are injected into the second chiral column 

where they are enantiomerically differentiated. 

Enantiomeric differentiation of oxygenated terpenes could be carried out using ( 1 H and 13 C) 

NMR spectroscopy and a chiral lanthanide shift reagent (CLSR). Although that technique was 

hardly used, some examples have been reported. The enantiomeric composition of linalool isolated 

from the oil of coriander was established by 1 H NMR, and the result was in agreement with that 

obtained by conventional polarimetry (Ravid et al. 1985). 13 C NMR and CLSR were successfully 

employed by Fraser et al. (1973) for the determination of the enantiomers of alcohols and acetates. 

In our laboratories, enantiomeric differentiation was performed for oxygenated monoterpenes in the 

pure form and in EOs: camphor and fenchone in Lavandula stoechas EO (Ristorcelli et al. 1998) 

and bornyl acetate in the EO of Inula graveolens (Baldovini et al. 2003). 

8.2.3.8 two-step Procedure 

In this procedure, a small quantity of a substance is separated by fractionated distillation or a chromatographic 

technique—liquid chromatography (LC), HPLC, preparative GC—and then identified 

by comparison of its spectral data—MS, FTIR, UV, 1 H NMR, and sometimes 13 C NMR—with 

those of reference compounds. 

Weyerstahl et al. (2000) have used this procedure for several years to fully characterize very 

complex EOs. For instance, they partitioned Haitian vetiver oil by fractionated distillation, column 

chromatography, and transformation of alcohols into their methyl esters. In total, they identified by 

GC-MS and NMR more than 150 components. Among them, several tens are new sesquiterpenes; 

they were fully characterized by 1 H and 13 C NMR. In the same way, these authors analyzed an 

EO of Cistus ladaniferus gum (Weyerstahl et al. 1998). They fractionated 400 g of a commercial 

sample by various methods (treatment by alkaline solution, fractionated distillation, CC, and TLC). 

Compounds present as mixtures were identified by GC-MS, whereas pure components were fully 

characterized by usual spectroscopic techniques: MS and 1 H, and 13 C NMR. The authors identified, 

in total, 186 components; among them, 26 are new compounds. 

Bicchi et al. (1998) used the same techniques to fractionate an essential oil from Artemisia roxburghiana. 

They identified 108 components, mainly by GC(RI) and GC-MS. However, 23 of these


components were sesquiterpene isomers, and their identification required the use of 1 H NMR and, 

sometimes, 13 C NMR. 

This two-step procedure is obviously more accurate, but it is very time consuming and requires 

a large quantity of EO. 

8.3 analysIs oF Cymbopogon oIls 

The composition of Cymbopogon oils was investigated a long time ago, in connection with 

the properties of the oils. Most studies concerned oils of commercial importance: citronella, 

lemongrass, and palmarosa oils. Citronella oils are usually divided into two types: Ceylon type 

and Java type obtained from C. nardus (L.) Rendle and C. winterianus Jowitt. Lemongrass oil 

is found either in Cymbopogon citratus Stapf (sometimes known as West Indian lemongrass) or 

in C. flexuosus Stapf. Palmarosa oil is produced from C. martinii (Roxb.) Wats. var martinii. 

The compositions of these oils have been reviewed by Lawrence (1979, 1989, 1993, 1995, 2003, 

2006). However, the compositions of various oils obtained from other species of Cymbopogon 

are reported in the literature, among others: C. afronardus, C. distans, C. giganteus, C. jawarancusa, 

C. microstachys, C. olivieri, C. parkeri, C. travancorensis, and C. validus. 

Cymbopogon oils contain mainly oxygenated monoterpenes: geranial, neral (citral), citronellol, 

geraniol, etc. (Figure 8.2). However, a great variety of compounds was reported as minor components: 

monoterpene hydrocarbons, sesquiterpene hydrocarbons and oxygenated sesquiterpenes, 

phenylpropanoids, and nonterpenic acyclic compounds. 

Depending on the various techniques (chemical, chromatographic, spectroscopic) used to 

identify and quantify the individual components of Cymbopogon EOs, we first remember the analysis 

by chemical methods. Then, we shall develop the analysis by chromatographic techniques, 

analysis by mass spectrometry coupled with gas chromatography, and analysis by hyphenated 

techniques. We shall summarize the enantiomeric differentiation of terpenes by chiral GC and 

by NMR. Finally, the combined analysis of EOs by various techniques will be exemplified on 

C. giganteus oil. 

O 

1 2 

3 

OH 

O O 

OH 

4 5 6 

FIgure 8.2 1 = geranial, 2 = citronellal, 3 = neral, 4 = geraniol, 5 = citronellol, 6 = myrcene.


8.3.1 ea r l i e s t st u d i e s: an a ly s i s by Ch e M iC a l Me t h o d s (is o l at i o n o f Co M P o u n d s 

a n d Mi sC e l l a n e o u s Me t h o d s) 

According to Lawrence (1989c), the first studies date back to 1948 when Dasgupta and Narain 

used fractional distillation and chemical derivatization in combination with physicochemical data to 

identify geraniol and a few derivatives in a sample of palmarosa oil from India. Later, the content of 

citral in lemongrass oil was determined by condensation with barbituric acid (Lawrence 1995b). 

Several sesquiterpene hydrocarbons were isolated from citronella oil from Java: β-bourbonene, 

δ-cadinene, α-cubebene, β-elemene, and α-selinene (Lawrence 1989a). 

Various physical and chemical methods were developed to isolate the major constituents of 

Cymbopogon oils. For instance, the sodium method was used to isolate the alcoholic constituents 

(mostly geraniol and citronellol) of the EO of Java citronella, and it was suggested that this method 

was more efficient than removal of alcohols by fractionated distillation (Lawrence 1979a). Various 

chemical and chromatographic methods were compared to evaluate the total citral content in lemongrass 

oil: bisulfite method, oxime method, barbituric acid method, GC with internal standard, 

and the GC method after NaBH 4 reduction. The authors recommended that the GC method using 

phenylethyl alcohol as internal standard was the most accurate method for determination of citral 

(Lawrence 1995b). 

Only a few new compounds have been isolated from Cymbopogon oils and their structure 

elucidated. 

C. flexuosus oil contained iso-intermedeol, a sesquiterpene alcohol (Thappa et al. 1979; Huffman 

and Pinder 1980), and later, both the oil and the alcohol were investigated for their ability to induce 

apoptosis in human leukemia HL-60 cells because dysregulation of apoptosis is the hallmark of 

cancer cells (Kumar et al. 2008). 

Evans et al. (1982) reported that the sesquiterpene diol proximadiol (Figure 8.3), with antispasmodic 

properties, earlier isolated from Cymbopogon proximus, is in fact identical with cryptomeridiol. 

An eudesmandiol, [2R-(2α,4aβ,8α,8aα)]-decahydro-8a-hydroxy-α,α4a,8-tetramethyl-2-naphthalene 

methanol, was isolated from the EO of Cymbopogon distans. It was studied spectroscopically, 

and the absolute configuration was determined by means of x-ray diffraction (Mathela et al. 1989). 

HO 

OH 

H 

H OH 

OH 

OH OOH OH H OH 

7 8 

9 

H 

H 

OH 

10 

OH 

11 12 

FIgure 8.3 7 = proximadiol, 8 = 5α−hydroperoxy-β-eudesmol, 9 = 3-eudesmen-1β,11-diol, 10 = selin- 

4(15)-en-1β,11-diol, 11 = 7α,11-dihydroxycadin-10(14)ene, 12 = α-oxobisabolene. 

O


Cymbodiacetal, a novel dihemiacetal bis-monoterpenoid, isolated from the EO of C. martinii, 

was identified by means of x-ray diffraction (Bottini et al. 1987). 

Recently, various sequiterpene alcohols, including two new compounds, 5α-hydroperoxy-βeudesmol 

and 7α,11-dihydroxycadin-10(14)-ene (Figure 8.3), have been isolated from a pentane 

extract of C. proximus (El-Askari et al. 2003). 

Finally, it should be noted that the presence of α-oxobisabolene (bisabolone) (12%) (Figure 8.3) 

was reported in a sample of Ethiopian C. citratus oil (Abegaz et al. 1983). Melkani et al. (1985) also 

reported the occurrence of that compound in concentrations ranging from 18% to 68% in one of the 

oils of two varieties of C. distans. Isolation of (+)-1-bisabolone from C. flexuosus and its utilization 

as antibacterial agent has been patented. 

However, the chemical techniques were supplanted by the introduction, first of chromatographic 

techniques (TLC and, obviously, GC) and later of spectroscopic techniques (MS, IR, NMR). 

8.3.2 an a ly s i s by Ch r o M at o G r a P h iC te C h n i q u e s [tlC, hPlC, GC(rt) o r GC(ri)] 

Due to the complexity of the EOs (number of constituents, diversity of the structures and functionalities, 

and also similarities resulting from the biosynthesis of terpenes from the same building block, 

the isoprene unit), TLC has not been considered a practical tool for analysis of Cymbopogon oils. 

Nevertheless, TLC has been used to characterize the quality of lemongrass oil from Bangladesh 

(Lawrence 1995). The authors concluded that the oil could be competitive on the market of citralrich 

oils. 

Following an improvement of the column for gas chromatography that allowed a good individualization 

of the components of essential oil, this technique became more and more useful for 

analysis of Cymbopogon EOs. 

The first experiments concerned the (tentative) identification of individual components, by comparison 

of their retention times with those of reference compounds: 

• As early as 1962, retention times were used to identify ten monoterpene hydrocarbon components 

in Ceylon citronella oil (Lawrence 1989a). 

• A few years later, eugenol and methyl eugenol were identified in the same way, besides 

monoterpenes, in a sample of Java citronella oil dominated by citronellal and geraniol 

(Lawrence 1989a); 

• In the meantime, Peyron (1973) was able to distinguish, among other monoterpenes, (Z) 

and (E) isomers of ocimene in palmarosa oil from Brazil, largely dominated by geraniol; 

• The same year, Wijesekera et al. (1973) reported the utilization of GLC profiles to distinguish 

both varieties of citronella oil, although both types contained comparable amounts of 

geraniol: Ceylon variety (Lenabatu) contained large amounts of monoterpene hydrocarbons, 

while the Java variety (Mahapengiri) contained only small amounts. In addition, the Ceylon 

type contained tricyclene, methyl eugenol, methyl isoeugenol, eugenol, and borneol; 

• Mohammad et al. (1981) determined the composition of two oil samples of lemongrass 

(C. flexuosus) and detected trace constituents using the peak enrichment technique (addition 

of a known compound in the EO and comparison of the new chromatogram with that 

of the pure oil). Besides neral and geranial, by far the main components, the authors identified 

various monoterpenes as well as decanal. The two samples also contained appreciable 

contents of farnesol and farnesal. However, the correct isomer of the two acyclic sesquiterpenes 

was not identified. 

More than 20 years later, Rauber et al. (2005) investigated a completely different approach to 

the quantitative determination of citral in C. citratus volatile oil. An HPLC method was developed 

(Spherisorb ® CN column, n-hexane: ethanol mobile phase, and UV detector) and validated


(precision, accuracy, linearity, specificity, quantification, and detection limits). The concentration 

of citral in C. citratus volatile oil obtained with this assay was 75%. 

8.3.3 an a ly s i s by Ma s s sPeC troM e try Co u P l e d w i t h Ga s Ch r o M at o G r a P h y 

In parallel, during the 1970s, owing to the improved sensitivity of mass spectrometers, identification 

of components became possible by comparison of their mass spectra with those of reference 

compounds. A gas chromatograph coupled with a mass spectrometer became the basic instrument 

for EO analysis. Using this technique, any volatile known compound, even present at the trace level, 

could be theoretically identified by comparison of its mass spectral data with those of reference 

compounds compiled in either paper or “computerized” libraries. 

A GC-MS study of the hydrocarbon fraction and the fraction containing oxygenated compounds 

showed the presence of 12 monoterpene hydrocarbons (28.4%), 13 sesquiterpene hydrocarbons 

(32.8%), 3 sesquiterpene alcohols (27.2%), 2 esters (7.2%), and 3 carbonyl compounds 

(4.4%) in the EO of C. distans. Among these, 27 compounds have been identified (Mathela and 

Joshi 1981). 

Analysis of an oil sample of C. flexuosus of Indian origin, by GC-MS, allowed the identification 

of monoterpenes (including perillene), various sesquiterpene hydrocarbons, as well as methyl 

eugenol and elemicin (Taskinen et al. 1983). 

In practice, the main drawback of that technique, particularly for the analysis of EOs, consists 

in the occurrence of insufficiently differentiated spectra for compounds built up with the same 

isoprene unit. Therefore, it was determined that sesquiterpenes bearing quite different skeletons 

exhibit similar (if not identical) mass spectra. Moreover, superimposable mass spectra are commonly 

observed for isomers (stereoisomers, diastereoisomers). Consequently, it is not surprising that 

the correct isomer of various monoterpenes and overall sesquiterpenes could not be identified by 

MS. In his excellent reviews, Lawrence pointed out the lack of specification of the correct isomer. 

For instance: 

• The correct isomer of various monoterpenes (menthone, isopulegols, and rose oxide) was 

not specified in the composition of citronella oils from Java and Sri Lanka investigated by 

GC-MS (Lawrence 1989a); 

• The isomer of verbenol contained in lemongrass ( C. citratus) grown in Zambia was not 

reported (Chisowa et al. 1998). Conversely, both isomers were found, as minor components, 

in oil samples from the Ivory Coast (Chalchat et al. 1998). 

• The correct isomer of elemene remained frequently unassigned in old papers and more 

surprisingly, in recent papers, as well as the stereoisomer of farnesol (Lawrence 2006d). 

Moreover, misidentification frequently occurred when the analysis was carried out only by MS. 

Concerning Cymbopogon oils, Lawrence, in his reviews, pointed out misidentified common compounds 

simply by the observation of the order of elution on apolar (or polar) column. Misidentifications 

concerned, in general, minor compounds but, sometimes, compounds present at appreciable 

contents. 

Anyway, year after year, MS became essential in EO analysis. Reliable results are obtained by combination 

of GC and MS. The combined use of both techniques will be developed in the next subsection. 

8.3.4 Co M b i n e d an a ly s i s by Ch r o M at o G r a P h iC a n d sP e C t r o s C o P iC 

te C h n i q u e s: tlC, CC, GC(rt) o r GC(ri) a n d GC-Ms 

In the previous text, we have seen the importance of both GC and MS for identification of individual 

components of EOs. Combination of the two techniques appeared really useful for analysis


of volatiles. Identification of individual components resulted from comparison of mass spectral data 

in the case of MS and retention times or retention indices in the case of GC with those of reference 

compounds. More accurate and reproducible results are obtained by using retention indices 

(Van Den Dool and Kratz 1963; Kováts 1965) instead of retention times (see Part I). 

Reliable results are obtained when individual components of EO are identified by MS in combination 

with RIs measured on two columns of different polarity (apolar and polar). Nowadays, it is 

considered by specialized reviews that analysis of an EO by at least two techniques should be done, 

to keep the work publishable. To facilitate identification of components, prefractionation of the oil 

by liquid chromatography (LC) could be useful. 

8.3.4.1 Cymbopogon oils of commercial Interest 

The first combined analyses, by GC and GC-MS, of Cymbopogon oils of commercial interest (citronella, 

lemongrass, and palmarosa oils), were published in the 1970s and have been reviewed by 

Lawrence (1979, 1989, 1993, 1995, 2003, 2006). Although the oil composition was always dominated 

by oxygenated monoterpenes (geranial, neral, and geraniol), the number and the structure of 

identified compounds varied substantially from paper to paper. 

The composition of lemongrass oil (C. flexuosus) from Guatemala was reported in 1976. Among 

unusual monoterpenes, the nonterpenic aldehyde decanal, as well as germacrene D and γ-cadinene were 

identified. The correct isomer of ocimene and allo-ocimene was not specified (Lawrence 1979b). 

A few years later, 2-undecanone was detected, by GC and GC-MS, in an Indian lemongrass oil 

sample containing more than 72% of citral (Lawrence 1989b). 

In 1983, two samples of Turkish lemongrass oil (C. citratus) were investigated by GC and GC-MS, 

after prefractionation of the oil by liquid chromatography. Both oils were dominated by citral, and 

they contained appreciable amounts of myrcene (up to 19%) as well as nonanal and 2-undecanone 

(Lawrence 1989b). 

Retention times and GC-MS data were taken into account to investigate an oil sample of 

C. winterianus from Bangladesh. Usual monoterpene hydrocarbons and monoterpenols were identified, 

as well as elemol and α-eudesmol. The authors also found 2,3-dimethyl-5-heptenal probably 

misidentified, according to Lawrence (1995a), instead of methylheptenone. 

Twelve samples of palmarosa oil produced in Madagascar were investigated by GC(KI) and 

GC-MS. Besides geraniol (major component) and usual monoterpenes, numerous sesquiterpenes 

were identified, although the coelution of various sesquiterpene hydrocarbons was observed. 

Three isomers of farnesol, (Z,E), (E,Z), and (E,E), were found and differentiated (Figure 8.4) 

(Randriamiharisoa and Gaydou 1987). The same authors reported the detailed analysis of the hydrocarbon 

fraction of that oil (4.75%), separated by CC (SiO 2) and analyzed by GC-MS in combination 

13 (E,E) 

13 (Z,E) 

13 (E,Z) 

FIgure 8.4 Structure of farnesol stereoisomers 13. 

OH 

OH 

OH


with KI. Twenty-eight sesquiterpene hydrocarbons were identified. In addition, long-chain alkanes 

were characterized. We note also the occurrence of the three isomers of cymene (Gaydou and 

Randriamiharisoa 1987). 

Ntezurubanza et al. (1992) identified the individual components of lemongrass oil from Rwanda, 

using MS in combination with RIs measured on two columns of different polarity (apolar and 

polar). They found 2-tridecanone and lavandulyl acetate, besides the usually seen monoterpenes. 

The chemical composition of commercial citronella oils of various geographical origins has been 

examined, using MS data and RIs (ethyl esters). Fifty-five compounds were identified, including 

various sesquiterpenes and phenyl propanoids (eugenol, methyl eugenol, E and Z isomers of methyl 

isoeugenol) (Lawrence 2003a). 

A Brazilian citronella oil sample, examined using GC(KI) and GC-MS, was found to contain 

citronellal and neral as major components while the content of geranial was very low. The phenyl 

propanoid elemicin accounted for 7% of the oil, which also contained β-elemene (0.5%) and elemol 

(3.7%) (Lawrence 1995a). 

Despite the improvement of analytical techniques, the analysis of complex mixtures, such as 

EOs, remains a difficult task and needs careful work. Unfortunately, despite using two analytical 

techniques (GC and GC-MS), misidentification of individual components still occurs as illustrated 

by the analysis of C. nardus oil from Zimbabwe, where numerous sesquiterpenes appeared misidentified 

on the basis of their relative elution order (Lawrence 2003a). 

The EO from seeds of Indian Cymbopogon martinii (Roxb.) Wats. var. motia Burk. collected from 

three different geographical locations was analyzed by capillary GC (KI measured on apolar and 

polar columns and peak enrichment by co-injection of authentic samples) and GC-MS (Mallavarapu 

et al., 1998). The composition of the oil samples was compared with that of the oil of flowering 

palmarosa herb. Besides the main constituent, geraniol (74.5%–81.8%), 55 other constituents were 

identified in the seed EOs. Although the composition of the seed oils is similar to that of the herb 

oil, quantitative differences in the concentration of some constituents were observed. The seed oil 

was found to contain lower amounts of geranyl acetate and higher amounts of (E,Z)-farnesol than 

the herb oil (two isomers of farnesol were differentiated in the oils). 

The composition of the leaf oil of C. citratus (DC) Stapf, growing on the campus of Lagos State 

University (Nigeria), was determined by the use of GC (KI on polar column) and GC-MS (Kasali 

et al. 2001). Twenty-three (97.3%) constituents were identified. The main components were geranial 

(33.7%), neral (26.5%), and myrcene (25.3%). An unusual saturated monoterpene hydrocarbon 

(0.1%) was also detected and probably misidentified as 2,6-dimethyloctane. 

The steam-distilled volatile oil obtained from partially dried grass (citronella grass) C. nardus 

(Linn.) Rendle, cultivated in the Nilgiri Hills, India, was analyzed by capillary GC and GC-MS 

(Mahalwal and Ali 2003). The prominent monoterpenes were citronellal (29.7%), geraniol 

(24.2%), γ-terpineol (9.2%), and cis-sabinene hydrate (3.8%). The predominant sesquiterpenes 

were (E)-nerolidol (4.8%), β-caryophyllene (2.2%), and germacren-4-ol (1.5%). An irregular 

monoter pene compound eluted among sesquiterpenes was identified as 3,3,6-trimethylhepta-1,5diene, 

and two 1,2-benzenze dicarboxylic acid derivatives were tentatively identified (although they 

are probably not naturally occurring substances). 

The EOs of palmarosa (C. martinii (Roxb.) Wats. var. motia Burk) flowering herbs from three 

different geographical locations in India (Hyderabad, Lucknow, and Amarawati) were analyzed by 

high-resolution GC (apolar column) and GC–MS (Raina et al. 2003). In all three samples, geraniol 

(67.6%–83.6%) was the major constituent. However, quantitative differences in the concentration of 

some constituents were observed. Among the three oils analyzed, Amarawati oil was of the highest 

quality due to higher geraniol (83.6%) and lower geranyl acetate (2.3%) and geranial (1.0%) content. 

Isopropyl propionate and butyrate (as well as cyclohexanone!) were detected in that oil. 

The supercritical fluid extraction (SFE) of C. citratus was performed in sequential and dynamic 

extraction modes (Sargenti and Lanças 1997). Principal compounds in the SFE extract were analyzed 

by GC and GC-MS and identified as neral, geraniol, and geranial. Nerolic acid and geranic


acid were identified as minor components in the essential oil. Different chromatographic profiles 

were obtained depending of the experimental conditions. 

The same technique was applied by Marongiu et al. (2006) who analyzed the influence of pressure 

on the supercritical extraction, in order to maximize citral content in the extract oil. Dried and 

ground leaves of lemongrass (C. citratus Stapf) were used as a matrix. The collected extracts were 

analyzed by GC-MS, and their composition was compared with that of the EO isolated by hydrodistillation 

and by steam distillation. At optimum conditions (90 bar and 50°C) citral represented 

more than 68% of the extract. At higher solvent density, the extract aspect changes because of the 

extraction of high-molecular-mass compounds. 

8.3.5 ot h e r Cy m b o p o g o n oils 

The composition of EO of other species has been also investigated: 

• The composition of the essential oil of C. jawarancusa (Khavi grass), was investigated by 

GC in combination with GC-MS (Saeed et al. 1978), and 64 compounds were identified. 

The oil exhibited a high content of piperitone (Figure 8.5; 60%–70%), which is mainly 

responsible for the smell of Khavi grass. The chemical variability of that oil was evidenced, 

and races rich in piperitone, phellandrene, and other chemical constituents have 

been identified (Dhar et al. 1981). 

• Analysis of the volatile oil of C. parkeri has been carried out by GC-MS (Rizk et al. 1983). 

To facilitate identification, prefractionation of the oil by adsorption high-performance liquid 

chromatography was performed. The major compounds are geraniol (33.5%), nerol 

(22.2%), geranyl acetate (8.9%), neryl acetate (3.8%), and farnesol (3.7%). A sesquiterpene 

alcohol that accounted for 4.8% remained unidentified. A quite different composition, 

determined by the use of GC and GC-MS, was reported for an oil sample obtained 

from aerial parts of C. parkeri Stapf, collected at flowering stage from Kerman province 

of Iran. The main constituents were piperitone (80.8%) and germacrene D (5.1%) (Bagheri 

et al. 2007). 

• The chemical composition of the essential oil of C. travancorensis Bor (Poaceae) was 

investigated by capillary GC and GC-MS. Thirty-five compounds were identified. The 

oil contains terpenes and phenyl propanoids (22.04%). The main constituents of the oil 

are limonene (18%), elemicin (17%), camphene (12%), elemol (11%), and borneol (10%) 

(Mallavarapu et al. 1992). 

• The steam-distilled oils from wild and cultivated C. validus (Stapf) Stapf ex Burtt Davy 

(Gramineae) were analyzed by GC and GC-MS (Chagonda et al. 2000). The major components 

from wild C. validus were the following: myrcene (23.1%–35.6%), (E)-β-ocimene 

(10.3%–11.5%), geraniol (3.4%–8.3%), linalool (3.2%–3.7%), and camphene (5.2%–6.0%). 

O 

14 

OH 

15 

OCH 3 

OCH 3 

OCH 3 

H 3 CO 

16 17 

FIgure 8.5 14 = piperitone, 15 = eugenol, 16 = (E)-methyl isoeugenol, 17 = elemicin. 

OCH 3 

OCH 3


• 

Cultivated mature plants contained myrcene (11.6%–20.2%), (E)-β-ocimene (6.0%–12.2%), 

borneol (3.9%–9.5%), geraniol (1.7%–5.0%), and camphene (3.3%–8.3%) as the major 

components. Young nursery crop/seedlings (20–30 cm high) contained oil with myrcene 

(20.6%), geraniol (17.1%), and germacrene-D-4-ol (8.3%) as main components. Geranyl 

acetate (4.5%), linalol (4.5%), and borneol (2.9%) were notable minor components. 

The constituents of the essential oil obtained by hydrodistillation of the aerial parts of 

C. olivieri (Boiss.) Bor, growing wild in Iran, was investigated by GC (RI on apolar column) 

and GC-MS (Norouzi-Arasi et al. 2002). Forty-two components, representing 97.6% 

of the oil, were identified, of which piperitone (53.3%), α-terpinene (13.6%), elemol (7.7%), 

β-eudesmol (4.4%), torreyol (3.3%), limonene (2.9%), and α-cadinol (2.1%) were the major 

components. 

C. microstachys (Hook.f.) Soenarko is reported to be found wild in some pockets of the Himalayan 

foothills of Assam, Uttar Pradesh, and West Bengal. Mathela et al. (1990) have studied the composition 

of its oil and identified 31 compounds. The oil was found to contain about 60% of phenyl propanoids 

with methyl eugenol (19.5%), methyl isoeugenol (4.2%), elemicin (25.3%), and isoelemicin 

(11.0%) (Figure 8.5). Another sample of C. microstachys had quite a different composition, with 

(E)-methyl isoeugenol being the main constituent (56.4%–60.7%) and myrcene (7.8%–12.2%) (Rout 

et al. 2005). 

C. afronardus oils, analyzed by GC and GC-MS, contained myrcene and intermedeol as major 

constituents. The oil is used in Uganda in the formulation of locally manufactured toothpaste (Baser 

et al. 2005). 

8.3.6 enantioMeriC differ entiation by Ch i r a l GC 

Ravid et al. (1992) carried out the enantioselective analysis of citronellol (10.2% in an oil sample 

of citronella) through a trifluoroacetyl derivative of the isolated compound; the (R)-(+)/(S)-(−) ratio 

was 74/26. 

Mosandl et al. (1990) used a combination of heart-cutting 2D GC and chiral GC to determine 

the enantiomeric distribution of monoterpene hydrocarbons in citronella oil: α-pinene [(+)/(−) = 

77/23] and limonene [(+)/(−) = 4/96] (Figure 8.6), and in lemongrass oil: α-pinene [(+)/(−) = 4/96], 

limonene [(+)/(−) = 0/100], and β-pinene [(+)/(−) = 0/100]. The enantiomeric composition of oxygenated 

monoterpenes was investigated: citronellol, linalool (Figure 8.6), terpinen-4-ol, cis and trans 

rose-oxides (Kreis and Mosandl 1994), linalool (Wang et al. 1995) lemongrass, and borneol (Ravid 

et al. 1996). 

The EO from aerial parts of C. winterianus Jowitt, cultivated in Southern Brazil, was analysed by 

GC-MS. Enantiomeric ratios of limonene [(R)-(+)/(S)-(−) = 13/87], linalool [(R)-(−)/(S)-(+) = 39/61]), 

citronellal [(R)-(+)/(S)-(−) = 91/09]), and β-citronellol [(R)-(+)/(S)-(−) = 85/15] were obtained by 

HO HO 

18(R) 18(S) 19(S) 19(R) 

FIgure 8.6 18(R) = (R)-(+)-limonene, 18(S) = (S)-(−)-limonene, 19(R) = (R)-(−)-linalool, 19(S) = (S)-(+)linalool.


multidimensional gas chromatography, using a developmental model setup with two GC ovens. The 

enantiomeric distributions are discussed as indicators of origin authenticity and quality of this oil 

(Lorenzo et al. 2000). 

8.3.7 Co M b i n e d an a ly s i s o f Cy m b o p o g o n oils by Va r i o u s te C h n i q u e s: 

tlC, CC, ir, GC(ri), GC-Ms, a n d 13 C nMr 

In various examples, the analysis was carried out by combination of chromatographic (TLC and 

GC) and spectroscopic (IR) techniques. This type of work is illustrated by the analysis of lemongrass 

oil (C. citratus) from Egypt. About 28 compounds were clearly detected by GC, from which 

17 were identified, citral being mentioned as a major component. The components belonged mostly 

to the acyclic-oxygenated monoterpenes. δ-Cadinene and (E)-β-caryophyllene were also identified 

(Abdallah et al. 1975). The oil was also analyzed by TLC, with a gradient of solvents as eluent. 

Citral, citronellal, and various alcohols were detected (Zaki et al. 1975). Finally, the infrared spectrum 

of the lemongrass oil proved that the changes in the samples during storage could be detected, 

especially the changes of the carbonyl groups (Foda et al. 1975). 

A combined analysis of citronella oil (C. winterianus) by fractional distillation, TLC, GC, IR, 

and NMR was described: besides citronellal and geraniol, the main components, four acyclic oxygenated 

monoterpenes, a cyclic one, a sesquiterpenol (elemol), and a phenylpropanoid (eugenol) 

were identified (Lawrence 1989a). 

An elegant and unusual technique was used to analyze the nitrogenous fraction of palmarosa oil. 

The compounds were separated by preparative GC and characterized using a combination of GC 

(nitrogen and sulfur detectors), GC-MS, IR, and NMR. Eighteen pyrazines, as many pyridines, four 

thiazoles, and a few other nitrogen-containing compounds were identified (Lawrence 1993). 

Very recently, the composition of the sample of palmarosa oil that has proven antimicrobial 

properties against cells of Saccharomyces cerevisiae was determined as 65% geraniol and 20% 

geranyl acetate, as confirmed by GC–FTIR (Prashar et al. 2003). 

In the early 1980s, NMR began to be employed to analyze EO. In 1981, Chiang et al. used proton 

NMR to quantify citronellal in Taiwanese citronella oil (average: 38.4%) (Lawrence 1989a). One 

year later, Formácek and Kubeczka (1982a) used a combination of GC and 13 C NMR to identify 

various monoterpenes, as well as 2-nonanone and (E)-β-caryophyllene in East Indian lemongrass. 

More recently, the same authors again used a combination of techniques, capillary GC, and 13 C 

NMR to compare the composition of citronella oil (C. nardus) and Java-type oil (C. winterianus) 

(Kubeczka and Formácek 2002). Both oils differed overall by the content of monoterpene hydrocarbons 

(camphene, limonene), oxygenated monoterpenes (citronellal, citronellol, borneol), and 

(E)-methyl isoeugenol. Forty-eight compounds were identified, including various sesquiterpenols 

and phenylpropanoids. 

Seven oil samples of C. schoenanthus were recently analyzed by GC(RI), GC-MS, and 13 C 

NMR, without fractionation (Khadri et al. 2008). The composition of samples was dominated by 

monoterpene hydrocarbons, limonene, β−phellandrene, and δ-terpinene. The last samples contained 

higher amounts of sesquiterpenes, including β-eudesmol, valencene, and δ-cadinene. All 

the components were identified by GC-MS and GC(RI). The identification of 17 components was 

confirmed by 13 C NMR. 

In our laboratories, we developed a computerized procedure allowing the identification of individual 

components of EOs, as illustrated in the first part of this chapter. We applied this method to 

the analysis of two samples of C. winterianus and a sample of C. tortilis, all cultivated in Vietnam 

(Ottavioli et al. 2008a). In all, 47 components were identified by a combination of GC(RI) on two 

columns of different polarity, GC-MS and 13 C NMR, in C. winterianus leaf oil. The composition 

of the first sample was largely dominated by geraniol (43.3%), citronellal (15.0%), citronellol 

(9.2%), and geranial (8.9%). It is noteworthy that all the 12 compounds, accounting for 91.6% of


HO 

H 

O 

CHO 

HO 

20 21 

FIgure 8.7 Structure of 20 = trans-7-hydroxy-3,7-dimethyl-3,6-oxyoctanal, 21 = cis-7-hydroxy-3,7dimethyl-3,6-oxyoctanal. 

the composition of the oil, were identified by GC-MS and by NMR. The composition of the second 

sample was also dominated by geraniol (50.2%) and geranial (8.3%), but citronellal and citronellol 

were present at very low levels. In that sample, 46 components were identified, 13 of these 

(accounting for 0.6%–50.2% each) by NMR. The same procedure was applied to the analysis of an 

oil sample from C. tortilis, without fractionation. The composition of that sample was dominated 

by geranial (32.0%) and neral (19.1%). The oil contained epoxyneral and epoxygeranial as well as 

caryophyllene oxide at appreciable contents. It differed drastically from the methyl-eugenol-rich oil 

from China (Liu et al. 1981). 

A leaf oil sample of C. flexuosus was analyzed by GC(RI), GC-MS, and 13 C NMR (Ottavioli 

et al. 2008b). The composition of the investigated sample was dominated by geranial (39.2%) 

and neral (24.1%), and was somewhat similar to that of various samples reported in the literature 

(Surburg and Panten 2006). Most of the identified compounds were classical components found in 

EOs, and they were identified by GC-MS by computer matching against commercial mass spectral 

data libraries and by comparison of their retention indices with those of reference compounds on 

two columns of different polarity. All the compounds, present at appreciable contents, were also 

identified by 13 C NMR, following the computerized method described earlier. However, two compounds, 

accounting for 4.5% and 4.4%, respectively, remained unassigned. Their retention indices 

on apolar and polar columns (compound A: RI = 1252 and 1957; compound B: RI = 1257 and 1940) 

led us to suspect two oxygenated monoterpenes. Computer matching of the 13 C NMR data against 

a home-made library constructed with literature data suggested the occurrence of cis- and trans-7hydroxy-3,7-dimethyl-3,6-oxyoctanal 

(Figure 8.7). 

To ensure the occurrence of both isomers, the oil from C. flexuosus was partitioned by flash chromatography 

on silica gel. Indeed, in the most polar fraction, eluted with diethyl oxide, both compounds 

accounted for 21.5% and 21.3%, respectively. Their NMR data were in agreement with those reported 

by Yarovaya et al. (2002). In parallel, analysis of the other fractions of chromatography by 13 C NMR 

confirmed the presence of minor monoterpenes, borneol, nerol, as well as sesquiterpenes, trans-αbergamotene, 

1,5-diepi-aristolochene, δ-cadinene, cuparene, β-elemol, and (2E,6E)-farnesol. 

To conclude this chapter, we illustrate the various techniques or combination of techniques and methods 

developed for analyzing EOs on a unique Cymbopogon species. To do that, we chose C. giganteus. 

8.3.8 an a ly s i s o f C. gi g a n t e u s oil: a su M M a r y o f an a ly t i C a l Me t h o d s 

in V o lV e d in t h e an a ly s i s o f Cy m b o p o g o n oils 

C. giganteus (Hochst.) Chiovenda is a perennial and sweet-smelling grass that grows spontaneously in the 

savannahs of Asian and African tropical regions. Aerial parts (leaves, flowers, stems) produce by vapor 

distillation or water distillation an EO whose composition has been studied by various techniques. 

The physiochemical properties of an oil sample (leaf and flower oil) from Côte d’Ivoire have 

been measured: density and refraction index as well as viscosity. The authors concluded that the oil 

is not Newtonian (Kanko et al. 2004). 

The composition of essential oils, obtained from aerial parts of plants growing in different countries, 

has been investigated: Benin (Ayedoun et al. 1997; Alitonou et al. 2006), Burkina Faso (Menut 

H 

O 

CHO


OH HO 

OH OH 

22 23 24 

25 

FIgure 8.8 Structure of 22 = trans-p-mentha-2,8-dien-1-ol, 23 = cis-p-mentha-2,8-dien-1-ol, 24 = trans-pmentha-1(7),8-dien-2-ol, 

25 = cis-p-mentha-1(7),8-dien-2-ol. 

et al. 2000), Cameroon (Ouamba 1991; Jirovetz et al. 2007), Côte d’Ivoire (Kanko et al. 2004; 

Boti et al. 2006), and Mali (Popielas et al. 1991; Keita 1993; Sidibe et al. (2001). 

Most analyses were carried out by a combination of GC(RI) and GC-MS, and the number of 

identified components varied substantially from 6 to 55. Whatever the origin, the composition 

of C. giganteus oils was dominated by monoterpenes, mostly oxygenated p-menthane derivatives, 

such as cis- and trans-p-mentha-2,8-dien-1-ols, cis- and trans-p-mentha-1(7),8-dien-2-ols, cis- and 

trans-isopiperitenols, limonene oxides, carvone, and limonene, the only monoterpene hydrocarbon 

found at appreciable content (Figure 8.8). 

Conversely, the oils differed from sample to sample by the occurrence of different minor components. 

Indeed, although several tens of compounds were identified in total in all the studies, only 

the six main compounds were identified in all the oil samples: cis- and trans-p-mentha-2,8-dien-1ols, 

cis- and trans-p-mentha-1(7),8-dien-2-ols, carvone, and limonene. Conversely, numerous compounds 

were identified only in one paper, including monoterpenes, acyclic nonterpenic compounds, 

and benzenoid derivatives. 

The first study on the chemical composition of C. giganteus essential oil was reported in 1991, 

for an oil sample from Bamako, Mali (flowering stage), investigated by GC(RT) and GC-MS (apolar 

column) (Popielas et al. 1991). Eighteen compounds were identified, the major ones being p-mentha- 

2,8-dien-1-ol (10.7%, isomer nonspecified), cis and trans-p-mentha-1(7),8-dien-2-ols (17.2% and 

20.4%, respectively). 1,2-Limonene oxide (13.7%, isomer nonspecified) was also among the major 

components. Isopiperitenol and trans-carveol coeluted. 

The next year, Keita (1993) published a short analysis of another oil sample of the plant of 

the same geographical origin, also carried out by GC(RT) and GC(MS). The menthadienols were 

not identified, although they were probably the main components (quoted as unidentified). Isopiperitenone 

accounted for 10.2% and carveol (isomer unspecified) for 8.0%. 

Finally, C. giganteus oil of Mali was also investigated by Sibidie et al. (2001) by GC (polar column) 

and GC-MS. Beside p-menthadienols, by far the main components, two p-menthatrienes and 

(Z)-2-phenylbut-2-ene were also identified. 

Ayedoun et al. (1997) investigated three oil samples hydrodistilled from plants harvested in 

different provinces of Benin. The three samples were characterized by high amounts of limonene 

(18%–24%) beside the four p-menthadienols. The essential oil of C. giganteus of Benin was 

also analyzed by GC and GC-MS. Once again, the major constituents were as follows: trans-p- 

1(7),8-menthadien-2-ol (22.3%), cis-p-1(7),8-menthadien-2-ol (19.9%), trans-p-2,8-menthadien-1-ol 

(14.3%), and cis-p-2,8-menthadien-1-ol (10.1%). This study reports the inhibitory effect produced by 

the chemical constituents of the essential oil, in vitro on 5-lipoxygenase (Alitonou et al. 2006). 

In the course of their studies on aromatic plants of tropical West Africa, Menut et al. (2000) 

reported the composition of an oil sample of C. giganteus from Burkina Faso. The analysis was


carried out by GC (two columns, apolar and polar) and GC-MS. The oil contained mainly limonene 

and a set of p-menthadienols. Two unusual esters, 3-methylbutyl hexanoate and octanoate, were 

also identified as minor components. The oil’s antioxidant and antiradical activities, which are low, 

were studied. 

The composition of C. giganteus oil from Cameroon has been first investigated by Ouemba 

(1991). A more detailed study was published very recently (Jirovetz et al. 2007). The EOs of fresh 

flowers, leaves, and stems of C. giganteus were investigated by GC and GC-MS. More than 55 

components have been identified in the three oil samples, the major ones being, as usual, the four 

p-menthadienol isomers. Additional components in higher concentrations, responsible for the characteristic 

aroma of these samples, are especially limonene, trans-verbenol, and carvone, as well as 

some other mono- and sesquiterpenes. Antimicrobial activities of the four oils were found against 

Gram-(+)- and Gram-(−)-bacteria, as well as the yeast Candida albicans, and these results were 

discussed with the compositions of each sample. 

The Cymbopogon giganteus oil from Côte d’Ivoire was only briefly investigated some time ago 

(nine components identified; Ouemba 1991). A more recent paper was no more informative (six 

compounds identified, method of analysis unspecified; Kanko et al. 2004). 

In order to get better insight into the composition of C. giganteus leaf oil from Côte d’Ivoire, a 

sample was analyzed using a combination of CC, GC(RI), GC-MS, and 13 C NMR (Boti et al. 2006). 

The bulk sample was analyzed by GC(RI), GC-MS, and 13 C NMR, and the fractions of chromatography 

were investigated by GC(RI) and 13 C NMR. In all, 46 constituents, which represented 

91.0% of the oil, were identified. As expected, cis- and trans-p-mentha-2,8-dien-1-ols (8.7% and 

18.4%), cis- and trans-p-mentha-1(7),8-dien-2-ols (16.0% and 15.7%), and limonene (12.5%) dominated 

largely the composition. Beside the main components, various compounds were present at 

appreciable contents: 3,9-oxy-mentha-1,8(10)-diene (2.2%), cis- and trans-isopiperitenols (2.2% and 

3.1%), carveol (2.2%), and carvone (2.7%). 

It should be pointed out that 22 compounds were identified by the three techniques. Obviously, 

all the major components were included in this group, which also contained some unusual compounds 

in C. giganteus oil, such as p-cymenene, 3-methylbutyl hexanaote and octanoate, safrole, 

precocene I, and caryophyllene oxide. A few other sesquiterpenes were identified for the first time in 

C. giganteus oil by GC-MS (β-elemene, (E)-β-caryophyllene, β-selinene, and δ-cadinene), besides 

nonterpenic esters (2-phenylethyl hexanoate and 2-phenylethyl octanoate). 

It is noteworthy that various compounds that were not identified by GC-MS of the whole oil 

sample were identified by 13 C NMR in the fractions of chromatography, in combination with RIs 

on apolar and polar columns: trans-dihydroperillaldehyde, geraniol, geranial, perillaldehyde, 

thymol, and ascaridole. The same association was useful for the identification of compounds 

that coeluted on apolar column, and consequently, although they were suggested by MS, they 

could not be accurately identified by this technique. For instance, trans- dihydrocarvone and cisdihydroperillaldehyde 

(RI = 1171) were identified by 13 C NMR in the fractions of chromatography, 

and then quantified by GC(FID) in the EO by comparison of their RIs on apolar and polar 

columns. 

A last interesting point is the identification of 3,9-oxy-p-mentha-1,8(10)-diene, not present in our 

MS and 13 C NMR data libraries. Its structure was determined by extensive NMR studies carried out 

on a fraction of chromatography where the oxide accounted for 80.0%, and then the NMR data were 

compared with those reported in the literature. 

In conclusion, the detailed analysis carried out by a combination of chromatographic and spectroscopic 

techniques, after fractionation of the bulk sample, gives better insight into the composition 

of the C. giganteus leaf oil from Côte d’Ivoire. Indeed, 25 compounds were reported for the first 

time in C. giganteus leaf oil, including oxygenated acyclic monoterpenes (citronellal, geraniol, geranial), 

oxygenated menthane derivatives (cis- and trans-dihydroperylaldehydes, thymol), phenylpropanoids 

(safrole), phenylethyl derivatives (hexanoate, octanoate), and oxides (ascaridole, precocene,


caryophyllene oxyde), as well as sesquiterpene hydrocarbons (β-elemene, (E)-β-caryophyllene, 

β-selinene, δ-cadinene) and linear aldehydes (nonanal, decanal) and alkanes. 


Nowadays, identification and quantitative determination of the individual components of EOs 

isolated from various species of Cymbopogon is mostly achieved by a combination of “on-line” 

chromatographic separation and spectroscopic identification. For that reason, a fast-scanning mass 

spectrometer directly coupled with a gas chromatograph is the basic equipment for such analyses. 

However, MS data should be considered in combination with retention indices (RIs). In summary, a 

component is identified (1) by comparison of its GC retention indices on polar and apolar columns, 

determined relative to the retention times of a series of n-alkanes with linear interpolation with those 

of authentic compounds or literature data; (2) on computer matching against laboratory-made and 

commercial mass spectral libraries and comparison of spectra with those of laboratory-made library 

or literature data. Identification by only one of the two techniques should be avoided, even for routine 

analysis. 

13 C NMR spectroscopy is an alternative method that has been used, at the beginning, to confirm 

the occurrence of a component, previously identified (or suggested) by MS or by RIs. Actually, the 

computerized comparison of the chemical shifts of signals in the 13 C NMR spectrum of the essential 

oil (EO) with those of reference spectra compiled in a library allows the identification of its 

main components, without previous separation. 

When the composition of an EO is investigated for the first time, more sophisticated techniques 

could be needed and a wide variety of combinations of analytical techniques are being developed, 

including complex hybrids such as GC-MS-MS, GC-MS-FTIR, HPLC-GC-MS, and HPLC- 1 H 

NMR-MS. Concerning Cymbopogon oils, to the best of our knowledge, none of these techniques 

have been used. Conversely, analyses of Cymbopogon oils have been carried out by a combination 

of various techniques, the oil being prefractionated by fractional distillation and/or column chromatography. 

Then, the fractions of chromatography have been analyzed by complementary techniques, 

GC(RI), GC-MS, 1 H, and 13 C NMR. Such types of analyses, which obviously are time consuming, 

provide unequivocal identification of the individual components present in EOs. Use of NMR spectroscopy 

for the analysis of natural mixtures is strongly encouraged by perfume, fragrance, and 

flavor manufacturers and quality control organizations. 


The authors are indebted to their coworkers and PhD students, who contributed substantially to this 

research. They appreciated the cooperation of colleagues of the universities of Corsica, Abidjan 

(Ivory Coast), and Hanoi (Vietnam). They acknowledge the Collectivité Territoriale de Corse and 

the European Community for partial financial support. 

reFerences 

Abd Allah M. A., Foda Y. H., Saleh M., Zaki M. S. A., and Mostafa M. M. (1975) Identification of the volatile 

constituents of the Egyptian lemongrass oil. Part I. Gas chromatographic analysis. Nahrung, 19, 

195–200. 

Abegaz B., Yohannes P. G., and Dieter R. K. (1983) Constituents of the essential oil of Ethiopian Cymbopogon 

citratus Stapf. J. Nat. Prod., 46, 424–426. 

Adams R. P. (2007) Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry, 

4th ed., Allured Publishing, Carol Stream, IL. 

Ahmad V. U. and Jassbi A. R. (1999) Analysis of the essential oil of Echinophora sibthorpiana Guss. by means 

of GC, GC/MS and 13C-NMR techniques. J. Essent. Oil Res., 11, 107–108.


Al-Burtamani S. K. S., Fatope M. O., Marwah R. G., Onifade A. K., and Al-Saidi S. H. (2005) Chemical composition, 

antibacterial and antifungal activities of the essential oil of Haplophyllum tuberculatum from 

Oman. J. Ethnopharmacol., 96, 107–112. 

Alencar J. W., Vasconcelos Silva M. G., Lacerda Machado M. I., Craveiro A. A., Abreu Matos F. J., and 

de Abreu Magalhães R. (1997) Use of 13 C-NMR as complementary identification tool in essential oil 

analysis. Spectroscopy, 13, 265–273. 

Alitonou G. A., Avlessi F., Sohounhloue D. K., Agnaniet H., Bessiere J. -M., and Menut C. (2006) Investigations 

on the essential oil of Cymbopogon giganteus from Benin for its potential use as an anti-inflammatory 

agent. Internat. J. Aromatherapy, 16, 37–41. 

Ayedoun M. A., Moudachirou M., and Lamaty G. (1997) Composition chimique des huiles essentielles de deux 

espèces de Cymbopogon du Bénin exploitable industriellement. Bioressources, Energie, Développement, 

Environnement, 8, 4–6. 

Badjah Hadj Ahmed A. Y., Meklati B. Y., and Fraisse D. (1988) Mass spectrometry with positive chemical 

ionization of some α-pinene and β-pinene derivatives. Flavour Fragr. J., 3, 13–18. 

Bagheri R., Mohamadi S., Abkar A., and Fazlollahi A. (2007) Essential oil compositions of Cymbopogon parkeri 

STAPF from Iran. Pakistan J Biol. Sci., 10, 3485–3486. 

Baldovini N., Tomi F., and Casanova J. (2003) Enantiomeric differentiation of bornyl acetate by carbon-13 

NMR using a chiral lanthanide shift reagent. Phytochem. Anal., 14, 241–244. 

Baldovini N., Tomi F., and Casanova J. (2001) Identification and quantitative determination NMR of furanodiene, 

a heat-sensitive compound, in essential oils by 13 C-NMR. Phytochem. Anal., 12, 58–63. 

Baser K. H. C., Özek T., and Demirci B. (2005) Composition of the essential oil of Cymbopogon afronardus 

Stapf from Uganda. J. Essent. Oil Res., 17, 139–140. 

Bicchi C., D’Amato A., and Rubiolo P. (1999) Cyclodextrin derivatives as chiral selectors for direct gas chromatographic 

separation of enantiomers in the essential oil, aroma and flavour fields. J. Chromatogr. A, 

843, 99–121. 

Bicchi C., D’Amato A., Manzin V., and Rubiolo P. (1997) Cyclodextrin derivatives in GC separation of racemic 

mixtures of volatiles. Part XI. Some applications of cyclodextrin derivatives in GC enantioseparations 

of essential oil components. Flavour Fragr. J., 12, 55–61. 

Bicchi C., Rubiolo P., Marschall H., Weyerstahl P., and Laurent R. (1998) Constituents of Artemisia roxburghiana 

Besser essential oil. Flavour Fragr. J., 13, 40–46. 

Blanc M. C., Bradesi P., Gonçalves M. J., Salgueiro L., and Casanova J. (2006) Essential oil of Dittrichia viscosa 

ssp. viscosa: Analysis by 13 C-NMR and antimicrobial activity. Flavour Fragr. J., 21, 324–332. 

Boelens M. H., Boelens H., and Van Germert L. J. (1993) Sensory properties of optical isomers, Perf. Flav., 

18, 1–16. 

Boti J. B., Muselli A., Tomi F., Koukoua G., N’Guessan T. Y., Costa J., and Casanova J. (2006) Combined analysis 

of Cymbopogon giganteus Chiov. Leaf oil from Côte d’Ivoire by GC/RI, GC-MS and 13C-NMR. 

C.R. Chimie, 9, 164–168. 

Bottini A. T., Dev V., Garfagnoli D. J., Hope H., Joshi P., Lohani H., Mathela C. S., and Nelson T. E. (1987) 

Isolation and crystal structure of a novel dihemiacetal bis-monoterpenoid from Cymbopogon martini. 

Phytochemistry, 26, 2301–2302. 

Bradesi P., Bighelli A., Tomi F., and Casanova J. (1996) L’analyse des mélanges complexes par RMN du 

carbone-13. Can. J. Appl. Spectrosc., 41, 15–24 and 41, 41–50. 

Bretmaier E. (2006) Terpenes, Flavors, Fragrances, Pharmaca, Pheromones. Wiley-VCH-Verlag GmbH and 

Co., Weinheim. 

Cavaleiro C. (2001) Öleos essenciais de Juniperus de Portugal. Thèse de doctorat, Université de Coïmbra. 

Cazaussus A., Pes R., Sellier N., and Tabet J. C. (1988) GC-MS and GC-MS-MS analysis of a complex essential 

oil. Chromatographia, 25, 865–869. 

Chagonda L. S., Makanda C., and Chalchat J. C. (2000) The essential oils of wild and cultivated Cymbopogon 

validus (Stapf) Stapf ex Burtt Davy and elionurus muticus (Spreng.) Kunth from Zimbabwe. Flavour 

Fragr. J., 15, 100–104. 

Chalchat J. C., Garry R. P., Harama M., and Sidibé L. (1998) A study of aromatic plants from Mali. Chemical 

composition of essential oils of two Cymbopogon varieties. Cymbopogon citratus and Cymbopogon 

giganteus. Riv. Ital. EPPOS, Spec. Num., 741–752. 

Chamblee T. S., Karelitz R. L., Radford T., and Clark B. C. (1997) Identification of sesquiterpenes in Citrus 

essential oils by cryofocusing GC/FT-IR. J. Essent. Oil Res., 9, 127–132. 

Chisowa E. H., Hall D. R., and Farman D. I. (1998) Volatile constituents of the essential oil of Cymbopogon 

citratus Stapf frown in Zambia. Flavour Fragr. J., 13, 29–30.


Coleman III W. M., Gordon B. M., and Lawrence B. M. (1989) Examinations of the matrix isolation Fourier 

transform infrared spectra of organic compounds: part XII, Appl. Spectrosc., 43, 298–304. 

Corticchiato M. and Casanova J. (1992) Analyse des mélanges complexes par RMN du Carbone-13. Application 

aux huiles essentielles. Analusis, 20, M51–57. 

De Medeci D., Pieretti S., Salvatore G., Nicoletti M., and Rasoanaivo P. (1992) Chemical analysis of essential 

oils of Malagasy medicinal plants by gas chromatography and NMR spectroscopy. Flavour Fragr. J., 7, 

275–281. 

Decouzon M., Géribaldi S., Rouillard M., and Sturla J. -M. (1990) A new look at the spectroscopic properties 

of dihydrocarveol stereoisomers. Flavour Fragr. J., 5, 147–152. 

Derome A. E. (1987) Modern NMR Techniques for Chemistry Research, Vol. 6, Organic chemistry series, 

J. E. Baldwin Ed., Pergamon Press, Oxford. 

Dhar A. K., Thappa R. K., and Atal C. K. (1981) Variability in yield and composition of essential oil in 

Cymbopogon jawarancus. Planta Med., 41, 386–388. 

Dugo P., Mondello L., Dugo L., Stancanelli R., and Dugo G. (2000) LC-MS for the identification of oxygen 

heterocyclic compounds in citrus essential oils. J. Pharm. Biomed. Anal., 24, 147–154. 

El-Askari H. I., Meselhy M. R., and Galal A. M. (2003) Sesquiterpenes from Cymbopogon proximus. 

Molecules, 8, 670–677. 

Evans F. E., Miller D. W., Cairns T., Vernon Baddeley G., and Wenkert E. (1982) Structure analysis of proximadiol 

(cryptomeridiol) by 13 C NMR spectroscopy. Phytochemistry, 21, 937–938. 

Ferreira M. J. P., Costantin M. B., Sartorelli P., Rodrigues G. V., Limberger R., Henriques A. T., Kato M. J., and 

Emerenciano V. P. (2001a) Computer-aided method for identification of components in essential oils by 

13 C NMR spectroscopy. Anal. Chim. Acta, 447, 125–134. 

Ferreira M. J. P., Brant A. J. C., Rodrigues G. V., and Emerenciano V. P. (2001b) Automatic identification 

of terpenoids skeletons through 13 C nuclear magnetic resonance data disfunctionalization. Anal. Chim. 

Acta, 429, 151–170. 

Foda Y. H., Abdallah M. A., Zaki M. S., and Mostafa M. M. (1975) Identification of the volatile constituents of 

the Egyptian lemongrass oil. Part III. Infrared spectroscopy. Nahrung, 19, 395–400. 

Formácek V. and Kubeczka K. H. (1982a) Essential Oils Analysis by Capillary Gas Chromatography and 

Carbon-13 NMR Spectroscopy, John Wiley & Sons, Chichester. 

Formácek V. and Kubeczka K. H. (1982b) 13C NMR Analysis of Essential Oils, in Aromatic Plants: Basic and Applied 

Aspects, pp. 177–18, Margaris N., Koedam A., Vokou D., Eds., Martinus Nijhoff Publishers, La Haye. 

Fraser R. R., Stothers J. B., and Tan C. T. (1973) Determination of optical purity with chiral shift reagents and 

13 C magnetic resonance. J. Magn. Reson., 10, 95–97. 

Gaydou E. M. and Randriamiharisoa R. P. (1987) Gas chromatographic diastereomer separation of linalool 

derivatives. Application to the determination of the enantiomeric purity of linalool in essential oils. 

J. Chromatogr., 396, 378–381. 

Gonny M., Bradesi P., and Casanova J. (2004) Identification of the components of the essential oil from wild 

Corsican Daucus carota L. using 13 C-NMR spectroscopy. Flav. Fragr. J., 19, 424–433. 

Grundschober F. (1991) The identification of individual components in flavorings and flavoured foods. 

Z. Lebensm Unters Forsch., 192, 530–534. 

Hedges L. M. and Wilkins C. L. (1991) Components analysis of eucalyptus oil by gas chromatography–Fourier 

transform–infrared spectrometry–mass spectrometry. J. Chromatogr. Sci., 29, 345–350. 

Huffman J. W. and Pinder A. R. (1980) Comments on the structure of isointermedeol, a sesquiterpene reported 

from Cymbopogon flexuosus. Phytochemistry, 19, 2468–2469. 

Jirovetz L., Buchbauer G., Eller G., Ngassoum M. B., and Maponmetsem P. M. (2007) Composition and antimicrobial 

activity of Cymbopogon giganteus (Hochst.) Chiov. Essential flower, leaf and stem oils from 

Cameroon. J. Essent. Oil Res., 19, 485–489. 

Joulain D. (1994) Methods for analyzing essential oils. Modern analysis methodologies: use and abuse. 

Perfurmer and Flavorist, 19, 5–17. 

Joulain D. and Laurent R. (1989) Two closely related sesquiterpenols: 1-endo-bourbonanol and 1,6-germacradien-5-ol. 

J. Essent. Oil Res., 1, 299–301. 

Joulain D. and König W. A. (1998) The atlas of spectral data of sesquiterpene hydrocarbons, E.B. Verlag, 

Hamburg. 

Kanko C., Koukoua G., N’Guessan Y. T., Fournier J., Pradère J. P., and Toupet L. (2004) Etude des propriétés 

physico-chimiques des huiles essentielles de Lippia multiflora, Cymbopogon citratus, Cymbopogon nardus, 

Cymbopogon giganteus. C.R. Chimie, 7, 1039–1042. 

Kasali A. A., Oyedeji A. O., and Ashilokun A. O. (2001) Volatile leaf oil constituents of Cymbopogon citratus 

(DC) Stapf. Flavour Fragr. J., 16, 377–378.


Keita A. (1993) Terpènes de l’huile essentielle des inflorescences de « ce kala » Cymbopogon anteus (Chiov.). 

Médecine Afr. Noire, 40, 229–233. 

Khadri A., Serralheiro M. L. M., Nogueira J. M. R., Neffati M., Smiti S., and Araujo M. E. M. (2008) Antioxidant 

and antiacetylcholinesterase activities of essential oils from Cymbopogon schoenanthus L. Spreng. 

Deter mi na tion of chemical composition by GC–mass spectrometry and 13 C NMR. Food Chemistry, 109, 

630–637. 

König W. A., Hochmuth D. H., and Joulain D. (2001) Terpenoids and related constituents of essential oils. 

Library of MassFinder 2.1, Institute of Organic Chemistry, Hamburg. 

Korhammer S. A. and Bernreuther A. (1996) Hyphenation of high-performance liquid chromatography (HPLC) 

and other chromatographic techniques (SFC, GPC, GC, CE) with nuclear magnetic resonance (NMR): A 

review. Fresenius J. Anal. Chem., 354, 131–135. 

Kováts E. (1965) Gas chromatographic characterization of organic substances in the retention index system, in 

Advances in Chromatography, vol. 1, pp. 229–247, Giddings J.C., and Keller R.A., Eds., Marcel Dekker, 

New York. 

Kreis P. and Mosandl A. (1994) Chiral compounds of essential oils. VVVII: Simultaneous stereoanalysis of 

Cymbopogon oil constituents. Flavour Fragr. J., 9, 257–260. 

Krock K. A., Ragunathan N., and Wilkins C. L. (1994) Multidimensional gas chromatography coupled with 

infrared and mass spectrometry for analysis of Eucalyptus essential oils, Anal. Chem., 66, 425–430. 

Kubeczka K. H. (1985) Progress in isolation techniques for essential oil constituents, in Essential Oils and 

Aromatic Plants, pp. 107–126, Baerheim Svendsen and Scheffer Eds., Nijhoff Junk pub, Dordrecht. 

Kubeczka K. H. and Formácek V. (2002) Essential oils analysis by capillary gas chromatography and carbon-13 

NMR spectroscopy. Second ed. John Wiley & Sons, NY, pp. 67–80. 

Kumar A., Malik F., Bhushan S., Sethi V. K., Shahi A. K., Kaur J., Taneja S. C., Qazi G. N., and Singh J. (2008) 

An essential oil and its major constituent isointermedeol induce apoptosis by increased expression of 

mitochondrial cytochrome C and apical death receptors in human leukaemia HL-60 cells. Chem.-Biol. 

Interactions, 171, 332–347. 

Lange G. and Schultze W. (1988a) Differentiation of isopulegol isomers by chemical ionization mass spectrometry, 

in Bioflavour ‘87, p. 115–122, P. Schreier Ed., W. de Gruyter and Co., Berlin. 

Lange G. and Schultze W. (1988b), Studies on terpenoid and non-terpenoid esters using chemical ionization 

mass spectrometry in GC/MS coupling, in Bioflavour’87, pp. 105–114, Schreier P. Ed., de Gruyter W. 

and Co., Berlin. 

Lawrence B. M. (1979a) Citronella oil, in Essential Oils 1976–1978, p. 22, Allured Publishing Co., Carol 

Stream, IL. 

Lawrence B. M. (1979b) Lemongrass oil, in Essential Oils 1976–1978, p. 20 and pp. 30–31, Allured Publishing, 

Carol Stream, IL. 

Lawrence B. M. (1989a) Citronella oil, in Essential Oils 1981–1987, pp. 29–31 and pp. 147–149, Allured Publishing, 


Lawrence B. M. (1989b) Lemongrass oil, in Essential Oils 1981–1987, p. 111, Allured Publishing, Carol 

Stream, IL. 

Lawrence B. M. (1989c) Palmarosa oil, in Essential Oils 1981–1987, pp. 237–239, Allured Publishing, Carol 

Stream, IL. 

Lawrence B. M. (1993) Palmarosa oil, in Essential Oils 1988–1991, pp. 81–82, Allured Publishing, Carol 

Stream, IL. 

Lawrence B. M. (1995a) Citronella oil, in Essential Oils 1992–1994, pp. 82–83 and p. 196, Allured Publishing, 


Lawrence B. M. (1995b) Lemongrass oil, in Essential Oils 1992–1994, p. 60, Allured Publishing, Carol 

Stream, IL. 

Lawrence B.M. (2003a) Citronella oil, in Essential Oils 1995–2000, pp. 52–53 and pp. 201–203, Allured Publish 

ing, Carol Stream, IL. 

Lawrence B. M. (2003b) Ginger grass oil, in Essential Oils 1995–2000, pp. 345–346, Allured publishing, Carol 

Stream, IL. 

Lawrence B. M. (2003c) Lemongrass oil, in Essential Oils 1995–2000, pp. 206–210, Allured Publishing, Carol 

Stream, IL. 

Lawrence B. M. (2003d) Palmarosa oil, in Essential Oils 1995–2000, pp. 334–335, Allured Publishing, Carol 

Stream, IL. 

Lawrence B. M. (2006a) Citronella oil, in Essential Oils 2001–2004, pp. 142–145, Allured Publishing, Carol 

Stream, IL.


Lawrence B. M. (2006b) Lemongrass oil, in Essential Oils 2001–2004, pp. 128–132, Allured Publishing, Carol 

Stream, IL. 

Lawrence B. M. (2006c) Palmarosa oil, in Essential Oils 2001–2004, pp. 77–78 and pp. 313–314, Allured 

Publishing, Carol Stream, IL. 

Lawrence B. M. (2006d) Citronella oil. Perf. Flav., 31, 10, 46. 

Liu C., Zhang J., Yiao R., and Gan L. (1981) Chemical studies on the essential oils of Cymbopogon genus. 

Huaxue Kuebao 241–247. 

Lorenzo D., Dellacassa E., Atti-Serafini L., Santos A. C., Frizzo C., Paroul N., Moyna P., Mondello L., and 

Dugo G. (2000) Composition and stereoanalysis of Cymbopogon winterianus Jowitt oil from Southern 

Brazil. Flavour Fragr. J., 15, 177–181. 

Mahalwal V. S. and Ali M. (2003) Volatile constituents of Cymbopogon nardus (Linn.) Rendle. Flavour 

Fragr. J., 18, 73–76. 

Mallavarapu G. R., Rajeswara Rao B. R., Kaul P. N., Ramesh S., and Bhattacharya A. K. (1998) Volatile 

constituents of the essential oils of the seeds and the herb of palmarosa (Cymbopogon martinii (Roxb.) 

Wats. var. motia Burk. Flavour Fragr. J., 13, 167–169. 

Mallavarapu G. R., Ramesh S., Kulkarni R. N., and Syamasundar K. V. (1992) Composition of the essential oil 

of Cymbopogon travancorensis. Planta Med., 58, 219–220. 

Marongiu B., Piras A., Porcedda S., and Tuveri E. (2006) Comparative analysis of the oil and supercritical CO 2 

extract of Cymbopogon citratus Stapf. Nat. Prod. Res., 20, 455–459. 

Mathela C. S., Melkani A. B., Pant A., Dev V., Nelson T. E., Hope H., and Bottini A. T. (1989) A eudesmanediol 

from Cymbopogon distans. Phytochemistry, 28, 936–938. 

Mathela C. S. and Joshi P. (1981) Terpenes from the essential oil of Cymbopogon distans. Phytochemistry, 20, 

2770–2771. 

Mathela C. S., Pandey C., Pant A. K., and Singh A. K. (1990) Phenylpropanoid constituents of Cymbopogon 

microstachys. J. lnd. Chem. Soc., 67, 526–528. 

McLafferty F. W. and Stauffer D. B. (1988) Wiley/NBS Registry of Mass Spectral Data, 4th ed., Wiley- 

Interscience, New York. 

McLafferty F. W. and Stauffer D. B. (1994) Wiley Registry of Mass Spectral Data. 6th ed. Mass Spectrometry 

Library Search System Bench–Top/PBM, version 3.10d, Palisade, Newfield, UK. 

Melkani A. B., Joshi P., Pant A. K., Mathela C. S., and Dev V. (1985) Constituents of the essential oils from 

two varieties of Cymbopogon distans. J. Nat. Prod., 48, 995–997. 

Menut C., Bessiere J. M., Samate D., Djibo A. K., Buchbauer G., and Schopper B. (2000) Aromatic plants of 

tropical west Africa. XI. Chemical composition, antioxidant and antiradical properties of the essential 

oils of three Cymbopogon species from Burkina Faso. J. Essent. Oil Res., 12, 207–212. 

Mohammad F., Nigam M. C., and Rahman W. (1981) Detection of new trace constituents in the essential oils 

of Cymbopogon flexuosus. Perf. Flav., 6, 29–31. 

Mondello L., Casilli A., Tranchida P. Q., Dugo P., and Dugo G. (2005) Comprehensive two-dimensional GC for 

the analysis of citrus essential oils. Flavour Fragr. J., 20, 136–140. 

Mondello L., Dugo G., Dugo P., and Bartle K. D. (1996) On-line HPLC-HRGC in the analytical chemistry of 

Citrus essential oils. Perf. Flav., 21, 25–49. 

Mondello L., Dugo P., and Bartle K. D. (1995) Automated HPLC-HRGC: A powerful method for essential oils 

analysis. Part V. Identification of terpene hydrocarbons of bergamot, lemon, mandarin, sweet orange, bitter 

orange, grapefruit, clementine and Mexican lime oils by coupled HPLC-HRGC-MS (ITD). Flavour 

Fragr. J., 10, 33–42. 

Mosandl A. (1988) Chirality in flavour chemistry—recent developments in synthesis and analysis. Food Rev. 

Intern., 4, 1–43. 

Mosandl A., Hener O., Kreis P., and Schmorr H. G. (1990) Enantiomeric distribution of a-pinene, b-pinene and 

limonene in essential oils and extracts. Part I. Rutaceae and gramineae. Flavour Fragr. J., 5, 193–199. 

NIST (1999) National Institute of Standards and Technology, PC Version 1.7 of The NIST/EPA/NIH mass 

spectral library. Perkin–Elmer Corp., Norwalk, CT. 

Norouzi-Arasi H., Yavari I., Ghaffarzade F., and Mortazavi M. S. (2002) Volatile constituents of Cymbopogon 

olivieri (Boiss.) Bor. from Iran. Flavour Fragr. J., 17, 272–274. 

Ntezurubanza L., Collin G., Deslauriers G., and Nizeyimana J. B. (1992) Huiles essentielles de Geranium et 

de lemongrass cultivées au Rwanda. Rivista Ital. EPPOS (Num. Spec.), 631–639. 

Núñez C. V. and Roque N. F. (1999) Sesquiterpenes from the stem bark of Guarea guidonia (L.) Sleumer 

(Meliaceae). J. Essent. Oil Res., 11, 439–440. 

Ottavioli J., Bighelli A., Casanova J., Bui Thi Bang, and Pham Van Y. (2008a) unpublished results.


Ottavioli J., Bighelli A., Casanova J., Bui Thi Bang, and Pham Van Y. (2008b) submitted. 

Ouamba J.-M. (1991) Valorisation chimique des plantes aromatiques du Congo. Extraction et analyse des huiles 

essentielles, Oximation des aldéhydes naturels, Thèse de Doctorat d’Etat, Université Montpellier II. 

Paolini J., Costa J., and Bernardini A. F. (2005) Analysis of the essential oil from aerial parts of Eupatorium 

cannabinum subsp. corsicum (L.) by gas chromatography with electron impact and chemical ionisation 

mass spectrometry, J. Chromatogr. A., 1076, 170–178. 

Peyron L. (1973) Sur quelques essences en provenance du Mato Grosso. Parfum. Cosmet. Savon. France, 3, 

371–378. 

Popielas L., Moulis C., Kéita A., Fouraste I., and Bessière J. M. (1991) The essential oil of Cymbopogon giganteus, 

Planta Med., 57, 586–587. 

Prashar A., Hili P., Veness R. G., and Evans C. S. (2003) Antimicrobial action of palmarosa oil (Cymbopogon 

martinii) on Saccharomyces cerevisiae. Phytochemistry, 63, 569–575. 

Raina V. K., Srivastava S. K., Aggarwal K. K., Syamasundar K. V., and Khanuja S. P. S., (2003) Essential oil 

composition of Cymbopogon martinii from different places in India, Flavour Fragr. J., 18, 312–315. 

Ramidi R., Ali M., Velasco-Negueruela A., and Pérez-Alonso M. J. (1998) Chemical composition of the seed 

oil of Zanthoxylum alatum Roxb. J. Essent. Oil Res., 10, 127–130. 

Randriamiharisoa R. P. and Gaydou E. M. (1987) Composition of palmarosa (Cymbopogon martini) essential 

oil from Madagascar. J. Agr. Food Chem., 35, 62–66. 

Rauber C. S., da Guterres S. S., and Schapoval E. E. S. (2005) LC determination of citral in Cymbopogon citratus 

volatile oil. J. Pharm. Biomed. Anal., 37, 597–601. 

Ravid U., Putievsky E., and Katzir I. (1992) Chiral GC analysis of enantimerically pure fenchone in essential 

oils. Flavour Fragr. J., 7, 169–172. 

Ravid U., Putievsky E., and Katzir I. (1996) Stereochemical analysis of borneol in essential oils using permethylated 

beta-cyclodextrin as a chiral stationary phase. Flavour Fragr. J., 11, 191–195. 

Ravid U., Putievsky E., Weinstein V., and Ikan R. (1985) Determination of the enantiomeric composition of 

natural flavouring agents by 1H-NMR spectroscopy, pp. 135–138 in Essential Oils and Aromatic Plants, 

Baerheim Svendsen and Scheffer Eds., Nijhoff Junk, Dordrecht. 

Rezzi S., Bighelli A., Castola V., and Casanova J. (2002) Direct identification and quantitative determination 

of acidic and neutral diterpenes using 13 C-NMR spectroscopy. Application to the analysis of oleoresin of 

Pinus Nigra. Appl. Spectrosc., 56, 312–317. 

Ristorcelli D., Tomi F., and Casanova J. (1998) Carbon-13 NMR as a tool for identification and enantiomeric 

differentiation of major terpenes exemplified by the essential oil of Lavandula Stoechas. Flavour 

Fragr. J., 13, 154–158. 

Rizk A. M., Heiba H. I., Sandra P., Mashaly M., and Bicchi C. (1983) Constituents of plants growing in qarar, 

constituents of the volatile oil of Cymbopogon Parkeri. J. Chromatogr., 279, 145–150. 

Rouessac F. and Rouessac A. (1994) Analyse chimique. Méthodes et Techniques Instrumentales Modernes. 

Masson, Ed., Paris. 

Rout P. K., Sahoo S., Rao Y. R. (2005) Essential oil composition of Cymbopogon microstachys (Hook.) 

Soenarke occurring in Manipur. J. Essent. Oil Res., 17, 358–360. 

Saeed T., Sandra P., and Verzele M. (1978) Constituents of essential oil of Cymbopogon jawarancusa. 

Phytochemistry, 17, 1433–1434. 

Sargenti S. R. and Lanças F. M. (1997) Supercritical fluid extraction of Cymbopogon citratus. Chromatographia, 

46, 285–290. 

Schultze W., Lange G., and Schmaus G. (1992) Isobutane and ammonia chemical ionization mass spectrometry 

of sesquiterpene hydrocarbons. Flavour Fragr. J., 7, 55–64. 

Sidibé L., Chalchat J. C., Garry R. P., and Lacombe L. (2001) Aromatic plants of Mali (IV): Chemical composition 

of essential oils of Cymbopogon citratus (DC) Stapf and Cymbopogon giganteus (Hochst) Chiov. 

J. Essent. Oil Res., 13, 110–112. 

Spring O., Buschmann H., Vogler B., Schilling E. E., Spraul M., and Hofmann M. (1995) Sesquiterpene lactone 

chemistry of Zaluzania grayana from on-line LC-NMR measurements. Phytochemistry, 39, 609–612. 

Surburg H. and Panten J. (2006) Common Fragrance and Flavor Materials, 5th ed., Wiley-VCH Verlag GmbH 

and Co., Weinheim. 

Taskinen Jyrki, Mathela D. K., and Mathela C. S. (1983) Composition of the essential oil of Cymbopogon 

flexuosus. J. Chromatogr. A, 262, 364–366. 

Thappa R. K., Dhar K. L., and Atal C. K. (1979) Isointermedeol, a new sesquiterpene alcohol from Cymbopogon 

flexuosus. Phytochemistry, 18, 671–672. 

Tomi F. and Casanova J. (2000) Contribution de la RMN du carbone-13 à l’analyse des huiles essentielles. Ann. 

Fals Expert. Chim., 93, 313–330.


Tomi F. and Casanova J. (2006) 13 C NMR as a tool for identification of individual components of essential oils 

from Labiatae—A review. Acta Horticult., 723, 185–192. 

Tomi F., Bradesi P., Bighelli A., and Casanova J. (1995) Computer-aided identification of individual components 

of essential oil using carbon-13 NMR spectroscopy. J. Magn. Reson. Anal., 1, 25–34. 

Van Den Dool H. and Kratz P. D. (1963) A generalization of the retention index system including linear temperature 

programmed gas-liquid partition chromatography, J. Chromatogr., 11, 463–471. 

Vernin G., Metzger J., Suon K.N., Fraisse D., Ghiglione C., Hamoud A., and Párkányi C. (1990) GC–MS– 

SPECMA bank analysis of essential oils and aromas. GC-MS (EI-PCI) data bank analysis of sesquiterpenic 

compounds in juniper needle oil—Application of the mass fragmentometry SIM technique, 

Lebensmittel-Wissenschaft Technol., 23, 25–33. 

Vernin G., Petitjean M., Poite J. C., Metzger J., Fraisse D., and Suon K. N. (1986) Computer Aids to Chemistry, 

Chap. VII, pp. 294–333, Vernin G., Chanon M., Horwood E., Eds., Mass Spectra and Kováts’ Indices 

Databank of Volatile Aroma Compounds, Chichester. 

Wang X. H., Jia C. R., and Wan H. (1995) The direct chiral separation of some optically active compounds in 

essential oils by multidimensional gas chromatography. J. Chromatogr. Sci., 33, 22–25. 

Weyerstahl P., Marschall H., Splittgerber U., and Wolf D. (2000) 1,7-Cyclogermacra-1(10),4-dien-15-al, a 

sesquiterpene with a novel skeleton, and other sesquiterpenes from Haitian vetiver oil. Flavour Fragr. J., 

15, 61–83. 

Weyerstahl P., Marschall H., Weirauch M., Thefeld K., and Surburg H. (1998) Constituents of commercial 

Labdanum oil. Flavour Fragr. J., 13, 295–318. 

Wijesekera R. O. B., Jayewardene A. L., and Fonseka B. D. (1973) Varietal differences in the constituents of 

citronella oil, Phytochemistry, 12, 2697–2704. 

Yarovaya O. I., Salomatina O. V., Korchagina D. V., Polovinka M. P., and Barkhash V. A. (2002) Transformations 

of 6,7-epoxy derivatives of citral and citronellal in various acidic media. Russian J. Org. Chem., 38, 

1649–1660. 

Zaki M. S. A., Foda Y. H., Mostafa M. M., and Abd Allah M. A. (1975) Identification of the volatile constituents 

of the Egyptian lemongrass oil. Part II. Thin Layer Chromatography. Food Nahrung, 19, 201–205.

9 

contents 

Citral from Lemongrass and 

Other Natural Sources 

Its Toxicology and Legislation 


9.1 Introduction ..........................................................................................................................223 

9.2 Uses and Dose Rate ..............................................................................................................227 

9.3 Natural Sources ....................................................................................................................227 

9.3.1 Litsea cubeba Oil ......................................................................................................227 

9.3.2 Lemongrass Oils .......................................................................................................229 

9.4 Manufacturing Methods .......................................................................................................230 

9.5 Analysis Methods .................................................................................................................230 

9.6 Toxicology ............................................................................................................................ 231 

9.6.1 RIFM ........................................................................................................................ 231 

9.7 Classification and Labeling ..................................................................................................234 

9.8 Safety Data Sheets ................................................................................................................ 235 

9.8.1 GHS ..........................................................................................................................236 

9.8.2 Reach ........................................................................................................................236 

9.9 Conclusion ............................................................................................................................236 

Acknowledgments ..........................................................................................................................237 

References ...................................................................................................................................... 237 

Other Sources .................................................................................................................................237 


Natural essential oils containing citral have been used in traditional and oriental folk medicines 

for millennia. The industrial manufacturing and chemical synthesis of citral has been known for 

more than a century, and even in the early stages of development, its reactivity and readily oxidizable 

characteristics were well known. It has long been considered best practice in laboratories and 

small-scale manufacturing units that spillages collected in absorbent paper or rags should be soaked 

in water before disposal to prevent combustion of citral and organic matter in the air. Citral is also 

active on human skin and can cause irritation, and even sensitization in some cases, although under 

“good manufacturing practice” and using personal protection equipment current in the industry, 

cases of reported problems are fortunately few. 

This chapter contains many acronyms used throughout this chapter and the trade, and these are 

listed in Table 9.1. More complete acronym lists are provided by some trade associations for their 

members, for example, BEOA, IFRA. Legislatively, citral is in the EU Annex I register of regulated 

substances as 605-019-00-3, in the ATP 19 (EFFA 2006). Citral consists of two isomers, neral 

[CAS 106-26-3] and geranial [CAS 141-27-5], usually occurring naturally in the ratio of 40:60. 

223


table 9.1 

acronyms listed in alphabetical order 

AISE Association Internationale de la Savonnerie de la Detergence & des Produits d’Entreti d’Entretien 

(European Soap and Detergent Assn.) 

ATP Adaptation of Technical Progress (EU Annex I), followed by revision no. 

BCF Bio Concentration Factor (REACH) 

BEMA British Essence Manufacturer’s Association 

BEOA British Essential Oils Association 

BFA British Fragrance Association 

CA Competent Authority (REACH) 

CAS Chemical Abstracts Service 

C&L Classification and Labeling 

CHIP Chemical Hazard Information Packaging 

CMR Carcinogen, Mutagen or Reproductive toxin (REACH) 

COE Council of Europe 

COLIPA Cote de Liaison European de Industrie de la Parfumerie de Produits Cosmetiques et de Toilette 

(European Cosmetic, Toiletry, and Perfumery Association) 

CREOD Center for Research Expertise in Occupational Disease (U.S.) 

CSA Chemical Safety Assessment (REACH) 

CSR Chemical Safety Report (REACH) 

CWG Commission Working Group (of the EU) 

DIN Deutsches Institut fur Normung (German Institute for Standardization) 

DNEL Derived No Effect Level — human health (REACH) 

DPD Dangerous Preparations Directive (88/379/EEC as amended) 

DSD Dangerous Substances Directive (67/548/EEC as amended) 

DU Downstream User (REACH) 

EC European Community (now European Union) 

EC0 Environmental concentration 0, the minimal quantity of a substance administered orally or dermally that 

does not kill any target population within a specified time 

EC 3 Prioritize and refer individuals for further assessment and care (EUSC) 

EC10 Environmental concentration 10: quantity of a substance administered orally or dermally required to kill 

10% of a target population within a specified time 

EC50 Environmental concentration 50: quantity of a substance administered orally or dermally required to kill 

50% of a target population within a specified time 

ECB European Chemicals Bureau 

E Ch A European Chemicals Agency (REACH) 

EEIII Joint Associations of ‘EFFA / EFEO / IFEAT / IFRA / IOFI’ 

EFEO European Federation for Essential Oils 

EFFA European Flavour and Fragrance Association 

EINECS European Inventory Notified Existing Chemical Substances 

ELINCS European List of Notified Chemical Substances 

ES Exposure Scenario (REACH) 

e-SDS Extended Safety Data Sheet, SDS for healthcare professionals (REACH) 

ESIS European Chemical Substances Information System (REACH) 

ESR Existing Substances Regulation (793/93/EEC) 

ETF Environmental Task Force (of IFRA) 

EU European Union 

EUCLID European Chemicals Information Database (REACH) 

EUROTOX European Federation of Toxicological Societies (REACH) 

EUSC End User Support Centre

Citral from Lemongrass and Other Natural Sources 225 



F&F Flavour & Fragrance (industry) 

FCC Food Chemical Codex (U.S.) 

FDA Food and Drug Administration (U.S.) 

FEMA Flavor Extract Manufacturers Association (U.S. Flavor Trade) 

FEXPAN FEMA Expert Panel 

FFIDS Flavor/Fragrance Ingredient Data Sheet 

FMA Fragrance Materials Association (U.S.) 

GC-MS Gas (liquid) Chromatography (combined) Mass Spectroscopy 

GHS Globally Harmonized System (REACH) 

GLC Gas Liquid Chromatography 

GLP Good Laboratory Practice 

GMP Good Manufacturing Practice 

HCWG Hazard Communication Working Group (of EFFA/IFRA/IOFI jointly) 

HPV High Production Volume Chemicals (REACH) 

HRIPT Human Repeat Insult Patch Test 

HSDS Health and Safety Data Sheet (EU) 

HSE Health and Safety Executive (U.K.) 

IC50 Infectious concentration 50: quantity of a substance administered orally or dermally required to kill 50% 

of a target population within a specified time 

IFEAT International Federation of Essential Oil and Aroma Trades 

IFRA International Fragrance Association 

IHCP Institute for Health and Consumer Protection 

INCI International Nomenclature of Cosmetic Ingredients 

In vitro Biological testing carried out “in glass,” for example, test tube, petri dish 

In vivo Biological testing carried out with humans or animals 

IOFI International Organisation of the Flavour Industry 

IOFI-CE IOFI Committee of Experts 

ISO International Standards Organization 

IUCLID International Uniform Chemicals Information Database (REACH) 

IUPAC International Union for Pure and Applied Chemistry 

JAG Joint Advisory Group of IFRA 

K o/c Coefficient of partition between Oil and Soil (log scale) 

K o/w Coefficient of partition between Oil and Water (log scale) 

LC50 Lethal concentration 50: quantity of a substance administered by inhalation, required to kill 50% of a 

target population within a specified time 

LD50 Lethal dose 50: quantity of a substance administered orally or dermally required to kill 50% of a target 

population within a specified time 

LLNA Local Lymph Node Assay 

LOAEL Lowest Observed Adverse Effect Level 

LOEL Lowest Observed Effect Level 

LOEC Lowest Observed Effect Concentration 

LPV Low Production Volume Chemicals (REACH) 

MAX Maximum Allowable Concentration 

MCS Multiple Component Substances (e.g., methyl ionone isomers) 

M/I Manufacturer/Importer (REACH) 

MITI Ministry of Trade and Industry (Japan) 

MSDS Material Safety Data Sheet (U.S.) 





NCS Natural Complex Substance (e.g., essential oils and extracts) 

NESIL No Expected Sensitization Induction Level 

NI Nature Identical 

NLP No-Longer Polymers (REACH) 

NOAEL No Observed Adverse Effect Level 

NOEC No Observed Effect Concentration 

NOEL No Observed Effect Level 

NOEL-MAX No Observed Effect Level for Maximum Allowable Concentration 

NORMAN Network Of Reference Laboratories Monitoring Emerging Environmental Pollutants 

OECD Organisation for Economic Cooperation and Development 

ORATS Online European Assessment Tracking System, EEC 793/93 

PADI Possible Average Daily Intake 

PBT Persistent Bio-accumulative Toxic Substance (REACH) 

PNEC Predicted No-Effect Concentration — environmental (REACH) 

PPORD Product and Process Oriented Research & Development (REACH) 

Ph Eur European Pharmacopoeia 

PRODAROM Syndicate National des Fabricants de Produits Aromatiques 

PRODUCE Piloting Reach On Downstream Users Compliance Exercise (REACH) 

QMRF QSAR Model Reporting Formats (ECB - for fish toxicity testing) (REACH) 

QRA Quantitative Risk Assessment (REACH) 

QSAR Quantitative Structure Activity Relationship (REACH) 

REACH Registration Evaluation Authorisation of Chemicals 

REXPAN RIFM Expert Panel 

RIFM Research Institute for Fragrance Materials 

RIP’s Reach Implementation Projects (REACH) 

RRIx Relative Retention Index (GLC term) 

RIPT Repeat Insult Patch Test 

RSC Royal Society of Chemistry (London) 

SAR Structure Activity Relationship (REACH) 

SARA Structure Activity Relationship Assessment (REACH) 

SCCNFP European Scientific Committee Cosmetics and Non Food Products (now SCCP) 

SCCP Scientific Committee on Cosmetology (EC) 

SHE Committee for Occupational Safety, Health and Environment 

SIEF Substance Information Exchange Forum (REACH) 

SME Small- and Medium-Sized Enterprise (REACH) 

SVHC Substances of Very High Concern (REACH) 

TEAMSPACE A Web site for posting all of the Reach Implementation Projects (RIPs) 

TGD Technical Guidance Document (REACH) 

TNO Information and Communication Technology (Netherlands) 

T/yr Tonnes per year (REACH) 

UNECE United Nations Economic Commission for Europe 

UNITIS European Organisation for Cosmetic Ingredient Industry and Services 

UVCB Unknown Variable Complex Botanicals (REACH) 

VPVB Very Persistent Very Bioaccumulative (REACH) 

WAF Water Accommodated Fraction (for eco-toxicity testing) (REACH) 

WGK Water Pollution Class (Wassergefahrdungsklasse), Germany 

WHO World Health Organisation 

WOE Weight of Evidence


table 9.2 

concentration of citral in Final Fragrance Product 

9.2 uses and dose rate 

Applications of citral in flavoring are widespread up to a reported average maximum level of 

430 ppm in chewing gum, a mean average daily consumption of 137 mg in baked goods, and a PADI 

of 25.27 ppm (RIFM 2006). It is reported as being used in beverages, baked goods, cheese, chewing 

gum, condiments, frozen dairy, puddings, gravies, candy, and meat products. Its use in fragranced 

products is limited by the IFRA standard, which restricts the level of use of citral in consumer goods 

(IFRA 2007). Hence, its characteristic perfumery notes are often substituted by alternative ingredients 

that have the added advantage of being more stable. This is particularly true in functional 

products, where stability is an issue and a use level in final product is reported (Food Cosmetics 

1979) in Table 9.2. 

9.3 natural sources 

Although citral occurs in many NCS (see Table 9.3), the first two on the list are the main commercial 

sources used for its extraction. 

Other more uncommon oils available commercially containing high levels of citral: 

9.3.1 litsea C u b e b a oil 

soap (%) detergent (%) creams, lotions (%) Perfume (%) 

Usual 0.02 0.002 0.005 0.2 

Maximum 0.2 0.02 0.02 0.8 

Lindera citriodora ~65% 

Backhousia citriodora ~95% 

Calypranthes parriculata ~62% 

Leptospermum liversidgei var. A ~75% 

Ocimum gratissimum ~66% 

The medium-sized tree Litsea cubeba, a member of the Lauraceae family, is commercially 

grown for essential oil distillation in the Yunnan and Guangxi Provinces of China, where it is 

known locally as May Chang. The fresh berries and leaves are cut and allowed to wilt before they 

are used for steam-distilled oil production. There are some differences in the composition of the oils 

derived from pure berries and pure leaves, and the collection of wood is best avoided because it can 

introduce low levels of toxic safrole into the oil. 

Litsea cubeba oil is mobile, pale yellow in color, with a powerful, fresh, intense herbal-lemon 

odor that is quite prominent. Virtually its only use is as a source of natural citral, which has several 

applications. In lemon flavors, it reinforces the main note, but it has limited stability in functional fragrance 

products. Citral is used for the synthesis of vitamin A and various ionone aroma chemicals. 

It has been featured in ISO standard 3214, last reviewed in 2000. The citral quoted therein was 

69.0% to 75.0%, measured by the ISO and FCC IV methods of GLC using a nonpolar column (Food 

Chemical Codex 1996). Classical wet analysis gives slightly higher results than this due to reaction 

of other minor components, leading to the usual commercial term of “70/75.”


table 9.3 

natural citral sources 

Citral (neral + geranial) Lemongrass oil


Assay typical: citral 72%, limonene 12%, linalol 1.5%, citronellol 0.2%, nerol 0.5%, geraniol 1%, 

1,8 cineole 1%, 6-methyl hepten-2-one 2%, pinenes 2%, sabinene 1%, β-myrcene 1%, verbenols 

2%, citronellal 1%, α-terpineol 0.5%, β-caryophyllene 1.5%, other monoterpene hydrocarbons 0.5%, 

other sesquiterpene hydrocarbons 0.2% = 99.9% (RSC EOC 2007). 

9.3.2 le M o n G r a s s oils 

The plants of lemongrass Cymbopogon citratus and C. flexuosus are members of the Poaceae family; 

they are medium-sized grasses that are commercially grown for essential oil distillation in 

Guatemala (C. citratus) and Cochin, India (C. flexuosus) (Arctander 1962). The fresh grass is cut 

and allowed to wilt before it is used for steam-distilled oil production. Oils from different regions 

have somewhat different compositions, Guatemalan West Indian (W.I.) having a slightly different 

citral content than East Indian (E.I.) Cochin origin. 

Lemongrass oil is mobile, pale yellow in color, with a powerful, fresh, floral-herbal odor that 

is quite prominent. Similar to Litsea cubeba oil, it is used as source of natural citral, but because 

this oil is more expensive and contains a higher level of geraniol (which is difficult to remove by 

distillation due to the closeness of its boiling point to that of the geranial isomer of citral), it is less 

popular; also, its flavor profile is slightly different compared to Litsea. Removal of the geraniol by 

absorption of the citral with alkaline bisulfite is a chemical treatment that results in the citral losing 

its natural status. 

These oils have been featured in the ISO standards 3217 (ISO 1974) and 4718 (ISO 2004); citral, 

quoted therein, was 70.0% to 75.0%. 

The physical constants recorded in ISO were ISO 3217:1974 and ISO 4718:2004 

Relative density at 20°C 0.872 to 0.897 0.885 to 0.905 

Refractive Index at 20°C 1.483 to 1.489 1.483 to 1.489 

Optical rotation at 20°C +1° to −3° +1° to – 4° 

The samples of oils analyzed of Guatemalan and Cochin origins conformed to these values and 

have the following registration and properties: 

CAS WI; 89998-14-1 [ISO, EFFA, EFEO, BEOA] 

EI; 91844-92-7 [ISO, EFEO, RIFM, BEOA] 

EINECS WI; 289-752-0 [ISO, EFEO, BEOA] 

EI; 295-161-9 [ISO, EFEO, BEOA, RIFM] 

TSCA 8007-02-1 [INCI, RIFM] 

FEMA 2624 

RIFM 5585 

EC 38n 

FDA 182.20 

INCI Cymbopogon schoenanthus oil; uses: tonic, masking 

Flash point: 71°C [EFEO, FMA] 

Log Kow calc. >3 calculated 

Assay typical W.I: citral 73%, geraniol 2.5%, nerol 1%, 6-methyl hepten-2-one 1%, limonene 8%, 

linalol 1%, eugenol 0.1%, citronellol 0.5%, citronellal 0.3%, neryl + geranyl acetates, 3%, verbenols 

3%, nonanone 1%, B-caryophyllene 2%, caryophyllene oxide 1%, other monoterpene hydrocarbons


2%, other sesquiterpene hydrocarbons 0.3% = 99.7% [7]. E.I: citral 78%, geraniol 3.5%, nerol 1.2%, 

6-methyl hepten-2-one 2.3%, limonene 0.3%, linalol 1%, eugenol 0.1%, citronellol 0.5%, citronellal 

0.3%, neryl + geranyl acetates 3%, verbenols 3%, nonanone 1%, B-caryophyllene 2%, caryophyllene 

oxide 1%, other monoterpene hydrocarbons 2%, other sesquiterpene hydrocarbons 0.3% = 99.5% 

(RSC 2007). 

9.4 manuFacturIng methods 

Ex-chemical synthesis: legislation: US—artificial, EU—nature identical. Assay 99%. 

The manufacturing methods are described in several books (Arctander 1969; Ohloff 1993). 

Synthesis can be based on acetylene chemistry (Kimel 1953) or isoprene (Leets et al. 

1957). 

Ex-NCS by absorption: legislation: US—artificial, EU—nature identical. Assay 99%. 

The essential oil is mixed with water, buffered to mildly alkaline conditions and a solution 

of sodium metabisulphite added, then thoroughly mixed by prolonged stirring. The citral 

dissolves in this aqueous phase and when stirring is stopped, the nonwater miscible phase 

floats to the surface and is separated. The aqueous phase is then neutralized with acid, and 

the citral separates as a floating layer. It is then washed with water and separated. It is then 

dried under vacuum or by filtering through a bed of anhydrous sodium sulfate. 

Ex-NCS by distillation: legislation: US—natural, EU—natural. Assay 92, 95, and 96%. 

Depending on the NCS source, some impurities such as geraniol are codistilled because 

their boiling points are close to that of citral. The current commercial preference is to use 

Litsea cubeba oil, with its lower geraniol content than lemongrass oil, as a higher assay 

citral can be obtained. However, some flavorists still prefer the flavor of citral ex lemongrass 

in lemonade applications, as the flavor is said to be closer to that of lemons. As can 

be seen, the production method affects the legislative status of the citral. 

9.5 analysIs methods 

GLC. The experienced chromatographer will often carefully examine GLC traces of the assay of 

citral using the FCC method (Food Chemical Codex 1996) on polymethylsiloxane phase columns, 

to look for the impurities that elute close to the citral peaks. The ISO standard method is to use an 

internal standard; it quotes a minimum 70% for the citral content of Litsea cubeba oil. On these 

nonpolar phases, the components elute in the order of their boiling points, as there is no interaction 

of the component with the stationary phase coating on the interior of the column. 

So, peaks that elute close to the citral isomers have similar boiling points and are particularly 

difficult to fractionate from citral, even under high vacuum on high theoretical plate Sulzer-packed 

fractionation columns. If these closely eluting peaks are present, it is difficult to achieve the higher 

assay, premium citral grades by distillation. 

GC-MS (Adams 1995) or GLC with relative retention indices on polarity-calibrated columns 

(RSC 1997) can be used to identify these components if necessary. 

Attempts to analyze citral using polar phase columns such as polyethylene glycol result in leading 

peaks and difficult quantification, as well as incomplete resolution of components. This is due to 

interaction of the aldehyde components with the alcohol radicals of the glycol phase. These effects 

can be overcome by reducing the citral to the corresponding alcohols with sodium borohydride 

before analysis (Jones et al. 1977). However, the widespread commercial acceptance of the FCC and 

ISO methods on nonpolar columns has made this effective but longer method all but obsolete. 

Titration. Assay of citral by titration of the aldehydes with standardized volumetric solutions 

gives good precision and accuracy, unless the oil under test contains citronellal or other aldehydes.


Absorption. A simple method of analysis, particularly suited to field-testing of citral-containing 

oils, is absorption into alkaline bisulfite solution (see manufacturing methods) in a cassia flask. This 

is usually a 200 mL conical flask with a long, slim, accurately graduated 10 mL by 0.1 ml neck. 

This flask can also be used for the determination of cinnamaldehyde in cassia oil (hence the name 

of the flask) and eugenol in clove, bay, and other oils containing it, by absorption into strong alkali. 

For citral determination, the flask is filled with alkaline bisulfite solution to the base of the flask 

neck zero line; 10.0 mL of the test citral oil is added, and the flask capped (usually with the technician’s 

thumb!) and vigorously shaken for several minutes, while the technician’s other hand supports 

the main bulb of the flask. The flask is then set aside to allow the phases to separate, and any 

unabsorbed oil components float to the top of the flask. The meniscus of this oil layer, which usually 

consists of terpene hydrocarbons, is simply read from the scale, subtracted from 10.0 mL of the 

test sample, and multiplied by 10 to get the percentage of absorbed citral. So, under the conditions 

described, if 10.0 mL of oil leaves 2.5 mL after absorption: 

10.0 (minus) 2.5 mL = 7.5 × 10 = 75% citral in the test oil 

9.6 toxIcology 

In terms of its PBT properties, citral has been rated as follows: 

Persistence = low; bioaccumulation = low; toxicity = medium 

The tests that are used for classification and labeling (C&L) are described as endpoints at which an effect 

is calculated. A list of these is shown in Table 9.4, with the results for citral given where available. 

QSAR. As can be seen from Table 9.4, there are many data gaps for the endpoints for citral, as 

they are not yet in the public domain. This presents a problem for the consortia registrants under the 

REACH regulations. A potential solution is to use the principles of QSAR to predict or supplement 

insufficient test data with predictions based on the structural relationships of other molecules, if 

they are available. 

Sometimes called SAR or SARA, this can be useful for the prediction of the level of concern 

regarding a material or even a mixture, with commercial computer programs available to aid in the 

prediction of toxicological concerns regarding a particular chemical structure (Lawrence et al. 2007). 

To quote from the draft regulations— 

… to facilitate the considerations of a (Q)SAR model for regulatory purposes, it should be associated 

with the following information: 

1. A defined endpoint 

2. An unambiguous algorithm 

3. A defined domain of applicability 

4. Appropriate measures of goodness-of-fit, robustness, and predictivity 

5. A mechanistic interpretation, if possible 

9.6.1 rifM 

Citral. According to RIFM, the Fragrance Structure—Activity Group for citral is “Aldehydes, 

branch chain, unsaturated,” and they have summarized the sensitization potency of citral. These are 

shown in Table 9.5. 

The potency classification of citral is as a weak sensitizer.


table 9.4 

endpoints in the QmrF with Values for citral 

Physicochemical effects 

Melting point °C = 27 mg/mL (rabbit) 

Acute oral toxicity 6800 mg/kg (rat) 

Acute dermal toxicity >5000 mg/kg (rabbit) 

Skin irritation at 20%, NOEL 4% 

Skin corrosion N/A 

Acute photo-irritation N/A 

Skin sensitization NESIL 1400 µg/cm 2



endpoints in the QmrF with Values for citral 

Respiratory sensitization N/A 

Photosensitization N/A 

Eye irritation/corrosion Irritation at 5% 

Mutagenicity E. coli; 0.1 mg/plate, no effect 

Photo mutagenicity N/A 

Carcinogenicity Strong suppressing activity, IC 50 < 0.00625% 

Photocarcinogenicity N/A 

Repeated dose toxicity N/A 

Developmental toxicity 22 d non-GLP, LOAEL = 60 mg/kg bw/d 

Fertility 20 d non-GLP, NOAEL = 0.43 mg/L 

Endocrine disruption: receptor binding Inhibited estrogen binding 

Endocrine disruption: gene expression N/A 

Toxicokinetics: skin penetration 63 min (mice) 

Toxicokinetics: ocular penetration N/A 

Toxicokinetics: gastrointestinal penetration N/A 

Toxicokinetics: blood–brain penetration N/A 

Toxicokinetics: placental penetration N/A 

Toxicokinetics: blood–testis penetration N/A 

Toxicokinetics: blood–lung penetration N/A 

Toxicokinetics: metabolism N/A 

Toxicokinetics: protein binding N/A 

* N/A = Not available. 

table 9.5 

sensitizing Potency for citral 

LLNA weighted mean EC 3 value In µg/cm2 = 1414 (11 studies) 

NOEL-HRIPT induction on human skin In µg/cm2 = 1400 

NOEL-MAX induction on human skin N/A 

LOEL induction on human skin In µg/cm2 = 3876 

WOE-NESIL In µg/cm2 = 1400 

The REXPAN conclusion is that the review of “the critical data for citral, based on the weight of 

evidence, established the No Expected Sensitization Induction Level as 1400 µg/cm 2 . They recommended 

the limits for the 11 different product categories, which derive from the application of the 

exposure-based quantitative risk assessment approach for fragrance ingredients, which is detailed 

in the QRA Expert Group technical dossier of March 15th 2006 (IFRA 2007). 

The 11 product categories can be found in Table 9.6 and replace the “wash-off” and “leave on” 

categories for consumer products that were used for many years. 

Cosmetics Directive EU. The EU 26th Cosmetics Directive, 7th amendment, lists citral as one 

of the 16 SCCNFP naturally occurring “alleged skin allergens” (there are 8 more aroma chemicals, 

plus oakmoss and treemoss for a total of 26). A paper was presented at the IFEAT conference 2001 

that explained these regulations, giving an XL spreadsheet of the maximum levels of these “16” 

in fragrance NCS (Moyler 2001). This XL was published by EFFA and distributed to its members 

at the same time, to enable the levels of the 16 in fragrance compounds to be calculated from 

the amounts added as such, plus the maximum contribution from the NCS, without the need to


table 9.6 

IFra classes of Product types (Qra) 

routinely analyze a complex fragrance. This is particularly helpful for SMEs, who then only need 

to use the IFRA GC-MS methods (Chaintreau et al. 2003; Leijs et al. 2005) for validation of the 

calculated result. 

9.7 classIFIcatIon and labelIng 

categories 

1. Lip products, insect repellents, toys 

2. Deodorants and antiperspirants 

3. Men’s facial balms and aftershaves, tampons 

4. Colognes, hair styling products, body lotions, foot care, strips for “scratch and sniff” 

5. Women’s makeup, hand cream, face masks 

6. Mouthwash, toothpaste, oral care 

7. Toilet paper, intimate wipes, baby wipes 

8. Make-up removers, nonaerosol hair styling products, nail care, talc 

9. Shampoo and conditioners, liquid soap, body and face cleansers, shaving creams, depilatory, 

shower gels, soap, feminine hygiene products, bath products, aerosols 

10. Hand-wash products, laundry cleaners, household cleaners, dish-wash cleaners, diaper cleaners, 

dry cleaning products, pet shampoos 

11. Candles, air fresheners, shoe polish, carpet cleaners, insecticides, toilet blocks, incense, machine 

dish wash, plastics, fuels, paints, cat litter, starch sprays, odorized water for steam irons 

Litsea cubeba 

Toxicology acute toxicity LD 50: oral, rat: >5000 mg/kg; dermal, rabbit: 4800 mg/kg 

Local effects LLNA, EC 3 8.4%; weak sensitizer [RIFM] 

Hydrocarbon content 15% (BEOA technical comm.) 

Kinematic viscosity 5000 mg/kg 

Local effects LLNA, EC 3 6.5% positive; weak sensitizer [RIFM] 

Hydrocarbon content WI 9 % (BEOA technical comm.) 

Kinematic viscosity


This means that the C&L, for an essential oil that contains citral, is based on that of citral at the 

near maximum level (usually the 95 percentile) to be found in the oil, unless the actual test data for 

the oil is “robust.” Robust test data are considered to be results based on modern protocols such as 

LLNA and, if available, they can be used to overrule the calculated data based on the DPD. 

Examples of the C&L for citral, Litsea cubeba oil, and lemongrass oils are as follows: 

Citral 

Transport—Not Regulated 

Evaluation: Sensitizer—Xi; IRRITANT 

Conclusion: RISKS: R 38 irritating to skin 

R 43 May cause sensitization by skin contact 

SAFETY: S(2) Keep out of reach of children (when sold to general public) 

S 24/25 Avoid contact with skin and eyes 

S 37 Wear suitable gloves 

Litsea cubeba 

Evaluation: Sensitizer—Xi, Harmful by Aspiration—Xn, Toxic to Environment—N 

HARMFUL 

Conclusion: Xn+N; R 38–43–51/53-65; S 24/25–37–61-62 

The “Xn” label and its associated R 65—S 62 phrases apply because the >10% hydrocarbon 

content of this oil creates the potential for the oil to be an aspiration hazard. This means that 

if the oil is swallowed by accident and the patient is induced to vomit, the mobile low viscosity 

hydrocarbons have the potential to coat the inner surface of the lungs and prevent the entry of 

breathed oxygen into the bloodstream, the potential danger being asphyxiation (BEOA 2006). 

This “Xn label” overrides the “Xi label” of the citral when both hazards are present. 

Lemongrass 

Evaluation: Sensitizer—Xi, Toxic to the Environment—N 

IRRITANT 

Conclusion: Xi+N; R 38-43-51/53; S 24-37-61 

The “N” label and its associated R 51/53—S 61 phrases apply to lemongrass and Litsea 

cubeba oils because the terpene hydrocarbons that they contain are slow to biodegrade in the 

environment and represent a potential hazard. 

9.8 saFety data sheets 

The data from the C&L is incorporated into safety data sheets (ISO 2001), which also include the 

physical properties, safe-handling instructions, and transportation guidelines for the material. These 

SDS are the mechanism for the communication of data for safe handling throughout the supply chain 

from manufacturer to the user, and a useful start for data gathering under the REACH registration.


9.8.1 Ghs 

In 1992, UNECE recognized that there were different regulatory standards being applied globally 

(EU: HSDS; U.S.: MSDS) and started work in a concerted way to bring these together in what has 

become known as the Globally Harmonized System. 

It is planned that an eSDS will be made available for professional users, which will contain additional 

toxicological and compositional data more detailed than that found on the HSDS. 

With the introduction of REACH (in Europe, the GHS is planned to be adopted at the same time), 

this has become an urgent matter, and there are technical specialist task forces operating in the U.S. 

and Europe that will then come together for the harmonization. 

This is to be achieved (simplistically) by enlarging the number of bands within each hazard 

group to accommodate the different classifications; for example, toxicity classes are expanded from 

the EU = 3 to GHS = 5, spanning the range up to LD 50 of 5000 mg/kg (based on rat oral tests). Some 

new categories are added as well, for example, respiratory sensitizers. 

There are some countries without their own system that had the option of adopting the GHS 

early; Brazil and New Zealand have done so, and Japan followed suit in December 2006. 

The rules of the GHS system do not allow for a “pick and mix” approach; either the CHIP or 

GHS system can be used until the introduction of the GHS, not some of each. 

One of the visible changes is the use of “diamond” pictograms for hazards, some of which are 

different from the “square” St. Andrews cross type, used under the CHIP regulations in the EU. 

9.8.2 re a C h 

Current CHIP GHS 

IRRITANT 

HARMFUL 

The European Parliament is introducing a registration system for chemicals that shifts the emphasis 

for the safe use of industrial materials from government to industry. All materials that are 

used at more than 1 tonne per annum are required to be registered, a registration that includes the 

modes of use. Depending on the volume of use and the hazard assessment, the amount of test data 

required to establish safe use increases, with the very high risk materials potentially substituted 

with safer alternatives. 

The mechanism for registration will be online by using IUCLID 5 [24] data, the latest version of 

the database that was first created in 1993 to meet the EU requirements of the ESR [25–28]. 


The toxicologic and legislative status of citral from all sources is covered by the EU legislation of 

Annex I. This is a listing that is binding under EU law, in recognition of the potentially harm to 

human health properties.


This chapter has reviewed the status with respect to the latest guidelines and uses of citral within 

the flavor and fragrance industries. 

The sources, production, toxicology, “classification and labeling,” industrial uses, and dose rates 

have been covered for citral itself and its natural sources. 

Future requirements of the GHS and REACH systems are also briefly explained. 

Citral is an invaluable material within the F&F industries, with a long, safe history of use and an 

important future, when used under GMP guidelines to protect those who handle it. 


I gratefully acknowledge the advice given by Dr. C. Letizia on toxicology and M. Milchard on testing 

data. 

My thanks to the directors of Fuerst Day Lawson for their support and kind permission to publish 

this paper. 

reFerences 

Adams R. P. 1995. Identification of EO Components by GC/MS, Allured Publishing, Carol Stream, IL. 

Arctander S. 1969. Perfume and Flavor Chemicals, Allured Publishing, Carol Stream, IL. 

Arctander S. 1962. Perfume and Flavors of Natural Origin, Allured Publishing, Carol Stream, IL. 

BEOA 2006. CHIP List and Handbook BEOA for members (Aug.). 

Chaintreau, A. et al. 2003. J. Agric. Food Chem 51: 6398–6403. 

EFFA Code of Practice August 2008. 

Food Chemical Codex 1996. National Academy Press, Washington DC ISBN 0-309-05394-3 IV July. 

Food Cosmetics Toxicology 1979. 17(3): 259–266. 

IFRA Standard 43rd Draft 2009. 

ISO Standard 3214. 2000. Litsea cubeba oil. 

ISO Standard 11041. 2001. Format for Safety Data Sheets. 

ISO Standard 3217. 1974. Lemongrass oil West Indian. 

ISO Standard 4718. 2004. Lemongrass oil East Indian. 

Jones R. A., Neale M. E., Ridlington J. 1977. J. Chromatography 130: 368. 

Kimel S. 1953. US patent 2,661,368 Hoffmann-LaRoche. 

Lawrence B. M., Hayes J. R., Stavanja M. S. 2007. Biological and Toxicological Properties in Mint—The 

Genus Mentha, CRC Press, Boca Raton, FL. 

Leets et al. 1957. J. Gen. Chem. USSR 27 1584; 1959. Chem. Abst. 53: 4336e. 

Leijs H. et al. 2005. J. Agric. Food Chem 53: 5487–5491. 

Moyler D. A. November 2001. On behalf of EFFA, Proceedings IFEAT Conf. Argentina. 

Ohloff G. 1993. Scent and Fragrances, Springer-Verlag. ISBN 0-387-57108-6. 

RIFM-FEMA. 2009. Database monograph 116. 

RSC essential oils committee. 2009. Perfumer & Flavorist to be published. 

RSC essential oils committee. 1997. The Analyst (London) 122: 1167–1174. 

other sources 

http://ecb.jrc.it/iuclid5/ 2006. 

http://ec.europa.eu/enterprise/reach/prep_guidance_en.htm 2006. 

http://ecb.jrc.it/REACH.htm 2006. 

http://europa.eu.int/comm/environment/chemicals/index.htm 2006. 

http://europa.eu.int/comm/enterprise/chemicals/index.htm 2006. 

http://www.reachready.co.uk 2007.

Index 

a 

Acyclic monoterpene hydrocarbons, 35 

Acyclic oxygenated monoterpenes, 36–40 

Afghanistan, trade, 156 

Agar diffusion method, 170 

Aging process, potential to control, 92 

Alloaromadendrene, 57 

Alpha tocopherol, 179 

Analytical methods, 195–221 

chemical methods, 196–197, 204–205 

chromatographic, spectroscopic techniques, combined, 

206–209 

chromatographic techniques, 197–198, 205–206 

gas chromatography, 197–198 

thin-layer chromatography, 197 

Cymbopogon giganteus, 212–215 

enantiomeric differentiation by chiral GC, 210–211 

fractional distillation, 196–197 

hyphenated techniques, 198–203 

13 C NMR, 200–201 

enantiomeric differentiation, 201–202 

GC-FTIR, 200 

GC-MS, 198–199 

GC-MS combined with GC(RI), 198–199 

GC-MS-FTIR, 200 

GC-MS-MS, 199–200 

GcxGC-MS, 199 

HPLC-GC-MS, 200 

HPLC- 1 H NMR, 200 

HPLC-MS, 200 

two-step procedure, 202–203 

mass spectrometry with gas chromatography, analysis 

by, 206 

various techniques, combined analysis by, 211–212 

Anatomy, Cymbopogon genus, 1–24 

Cymbopogon citratus leaf ultrastructure, 7 

generic characters, 5–6 

leaf anatomy, 5–7 

rubisco immunolocalization, 7 

Angola, trade, 156 

Antimicrobia/antioxidant activities, 167–183 

agar diffusion method, 170 

alpha tocopherol, 179 

citral, 179 

citronellal, 179 

citronellol, 179 

Cymbopogon citratus, 179 

Cymbopogon nardus, 179 

essential oil-solubilizing agents, 168 

factors affecting antimicrobial activity, 168–177 

factors affecting antioxidant activity, 178–180 

geraniol, 179 

Gram-negative bacteria, 169 

Gram-positive bacteria, 169 

limonene, 179 

media, 178–179 

methods used for antimicrobial assessment, 170–177 

mould, 169 

oil components, activity, correlation between, 169–170 

oxidation conditions, 179–180 

oxidizable substrate, end-product evaluation, 178 

serial broth dilution method, 170 

solubilizing agents, 168–169 

testing antioxidant activity, 180 

carotene bleaching assay, 180 

diphenyl-1-perylhydrazyl free radicals scavenging 

test, 180 

thiobarbituric acid reactive substance assay, 180 

type of organism, 169 

vapor contact assay, 170–177 

yeast, 169 

Argentina, trade, 164 

Aromadendrene, 57 

Australia, trade, 154, 156, 161, 164 

Austria, trade, 154, 156, 161 

b 

Bahrain, trade, 156, 164 

Bangalore, 32–33 

Bangladesh, trade, 156 

Belgium, 31 

trade, 156, 161 

Bergamot oil 

distilled, 228 

expressed, 228 

Bergamotene, 58 

Bhutan, trade, 160 

Bicyclic monoterpene hydrocarbons, 42–43 

Bicyclic oxygenated monoterpenes, 54–56 

Biochemistry, Cymbopogon genus, 1–24 

characterization of photosynthetic variant, 8–9 

CO 2 assimilation, 10 

NADP + inhibition of NADP-MDH, 9 

pH and temperature dependence of NADPH-MDH, 

NADP-ME, 9–10 

Biogenesis, essential oil from genus Cymbopogon, 26–27 

Biological activities, 84–95 

Biology, Cymbopogon genus, 1–24 

Biosynthesis, terpenes in Cymbopogon species, 79–84 

Biosynthesis of, terpenes in Cymbopogon species, 79–84 

Biotechnological studies, 137–142 

Bisabolene, 58 

Bisabolol, 59 

Bitter orange oil, 228 

Blood coagulation activity, 189 

Blood sugar, lowering of, 91 

Borneol, 54 

Bornyl acetate, 54 

Bosnia, trade, 161 

Botany, Cymbopogon genus, 1–24 

239

240 Index 

Brazil, trade, 154, 161 

Bulgaria, trade, 156 

Butenol, 59 

c 

Cadinene, 60–61 

Cadinol, 61 

Calamenene, 60 

Cambodia, trade, 156 

Camphene, 43 

Camphor, 54 

Canada, trade, 154, 156, 161, 164 

Cardamom oil, 228 

Carene, 42 

Carotene bleaching assay, 180 

Carvacrol, 44 

Carveyl acetate, 45 

Carvone, 45 

Carvotanacetone, 45 

Caryophyllene, 61 

Caryophyllene alcohol, 62 

Caryophyllene oxide, 62 

Ceylon, 28, 32, 228 

Chamigrene, 62 

Characterization of photosynthetic variant, 8–9 

Chemical analysis methods, 196–197 

analysis by, 204–205 

Chemistry, 26–27, 68–95 

Chile, trade, 156 

China, 228 

trade, 154, 156, 161 

Chinese Taipei, trade, 156 

Chromatographic, spectroscopic analysis techniques, 

combined analysis by, 206–209 

Chromatographic analysis techniques, 197–198 

analysis by, 205–206 

gas chromatography, 197–198 

thin-layer chromatography, 197 

Cineole, 46 

Cis-carveol, 44 

Cis-isopiperitenol, 47 

Cis-ocimene, 35 

Cis-p-menth-1(7),8-dien-2-ol, 49 

Cis-piperitenol, 51 

Cis-piperitol, 52 

Citral, 179, 223–237 

analysis methods, 230–231 

classification, 234–235 

dose rate, 227 

IFRA classes, product types, 234 

labeling, 234–235 

lemongrass oils, 229–230 

Litsea cubeba oil, 227–229 

manufacturing methods, 230 

natural citral sources, 228 

natural sources, 227–230 

RIFM, 231–234 

safety data sheets, 235 

toxicology, 231–234 

uses, 227 

Citral-a(Z), 36 

Citral-b(E), 36 

Citronella oil, 71–73, 151–153, 156–158, 228 

Citronellal, 37, 179 

Citronellol, 37, 179 

Citronellyl acetate, 37 

Citronellyl butyrate, 37 


Cochin, 28 

Colombia, trade, 156 

Combined analysis by various techniques, 211–212 

Congo, trade, 33, 156 

Costa Rica, trade, 156 

Cubebene, 63 

Cuparene, 63 

Cymbopogon, aromatic genus, 136–137 

Cymbopogon asmastonii, 79 

Cymbopogon caesius, 33, 75 

Cymbopogon citratus, 30–31, 69–71, 179 


Cymbopogon coloratus, 33, 75 

Cymbopogon confertiflorus, 75 

Cymbopogon densiflorus, 33, 76 

Cymbopogon distans, 33–34, 76 

Cymbopogon flexuosus, 16–17, 68–69 

Cymbopogon genus, 11–13 

analysis, 203–215 

analytical methods, 195–221 

anatomy, 4–7 


generic characters, 5–6 

leaf anatomy, 5–7 

rubisco immunolocalization, 7 

antimicrobial activities, in vitro, 167–183 

antioxidant activity, in vitro, 178–180 

aromaticity, 136–137 

biogenesis of essential oil from, 26–27 

biosynthesis of terpenes in, 79–84 

botany, 1–24 

chemistry, 26–27 

combined analysis, 211–212 

essential oil chemistry, 25–106 

harvest, 107–133 

physicochemical characteristics of essential oils, 

26–67 

postharvest management, 107–133 

trade in, 151–165 

uses of, 68–95 

biochemistry, 7–10 

characterization of photosynthetic variant, 8–9 



pH and temperature dependence of NADPH-MDH, 

NADP-ME, 9–10 

biochemistrygon genus, stomatal conductance, 10 

molecular biology, 11–13 

randomly amplified polymorphic DNA markers, 

11–13 

simple sequence repeat markers, 13 

physiology/ecophysiology, 14–20 

Cymbopogon flexuosus, 16–17 

Cymbopogon martinii, 14–16 

Cymbopogon winterianus, 17–18 

Cymbopogon giganteus, 79, 212–215 

Cymbopogon goeringii, 79 

Cymbopogon jwarancusa, 29, 74–75 

Cymbopogon khasianus, 77

Index 241 

Cymbopogon ladakhenis, 77 

Cymbopogon mardus, 127–128 

distillation, 128 

harvesting, 127–128 

uses, 127 

yield, 128 

Cymbopogon martinii, 14–16, 29–30, 73–74, 117–121 



oil content, yield, 120–121 

oil storage, 120 

standard specifications, 121 

storage, 119 

uses, 118 

yield, 119–120 

Cymbopogon microstachys, 77 

Cymbopogon nardus, 32, 72–73, 179 

Cymbopogon nervatus, 34, 77 

Cymbopogon oils, 151–165 

citronella oil, 151–153, 156–158 

demand, 152–153 

export, import, 153 

lemongrass oil, 153–162 

palmarosa oil, 160–164 

production, 159–160, 163–164 

world demand, 153 

world production, demand, 159 

Cymbopogon olivieri, 77 

Cymbopogon parkeri, 78 

Cymbopogon pendulus, 31, 71 

Cymbopogon polyneuros, 78 

Cymbopogon procerus, 78 

Cymbopogon rectus, 78 

Cymbopogon schoenanthus, 33, 75 

Cymbopogon sennarensis, 78 

Cymbopogon stracheyi, 78 

Cymbopogon tortilis, 78 

Cymbopogon travancorenis, 78 

Cymbopogon winterianus, 17–18, 31–32, 71–72, 121–127 

distillation procedure, 126 


hay storage, 126 

standard specifications, 126–127 

yield, 126 

Czech Republic, trade, 156 

d 

Denmark, trade, 156, 161 

Dihdrocarveol, 46 

Dihydro-alpha-copaene, 63 

Diphenyl-1-perylhydrazyl free radicals scavenging test, 

180 

Djibouti, trade, 156 

DPPH test. See Diphenyl-1-perylhydrazyl free radicals 

scavenging test; diphenyl-1-perylhydrazyl free 

radicals scavenging test 

e 

Ecophysiology, Cymbopogon genus, 14–20 




Ecuador, trade, 161 

Edema, activity to reduce, 92 

Egypt, trade, 156, 161 

Elemene, 64 

Enantiomeric differentiation by chiral GC, 210–211 

Epoxy-3,7-dimethyl-1,6-octadiene, 46 

Essential oil-solubilizing agents, 168 

Ethiopia, trade, 156 

Eucarvone, 45 

Eudesmol, 64 

Euglobulin, 186–187 

in vivo fibrinolytic activity, 189 

F 

Farnesene, 65 

Fenchone, 54 

Fibrin plate method, 186–187 

Fiji, trade, 156, 161 

Finland, trade, 156 

Fractional distillation, 196–197 

France, trade, 154, 156, 160–161, 164 

French South and Antarctic Territories, trade, 161 

Future developments, 135–149 

Cymbopogon, aromatic genus, 136–137 

biotechnological studies, 137–142 

future options, 142–144 

metabolic engineering studies, 141–142 

phylogenetic studies, 139–140 

tissue culture studies, 137–139 

g 

Gambia, trade, 156 

Gas chromatography, mass spectrometry with, analysis 

by, 206 

Generic characters, Cymbopogon genus, 5–6 

Geraniol, 38, 179 

Geranium oil, 228 

Geranyl acetate, 38 

Geranyl formate, 38 

Germacrene D, 66 

Germany, trade, 154, 156, 160–161, 164 

Ghana, trade, 156, 161 

Ginger oil, 228 

Gingergrass, 73–74 

Gram-negative bacteria, 169 

Gram-positive bacteria, 169 

Grapefruit oil, 228 

Greece, trade, 156, 161 

Guatemala, trade, 161 

Guyana, trade, 157 

h 

Haldwani, 31–32 

Harvest/postharvest management, Cymbopogons, 107–133 

citronella, 121–127 

distillation procedure, 126 


hay storage, 126 

standard specifications, 126–127 

yield, 126 

jamrosa, 127–128

242 Index 



uses, 127 

yield, 128 

lemongrass, 109–117 

condensers, 114 

distillation, 113–115 

drying, 113 


oil separators, 114–115 


predistillation handling, 112–113 

purification of oil, 116 

quality analysis, 116–117 

steam boiler, 114 

stills, 114 

storage, 113 

storage and packing of oil, 116 

supercritical fluid extraction, 115–116 

treatment of oil prior to storage, 116 

yield, 112–116 

palmarosa, 117–121 






storage, 119 

uses, 118 

yield, 119–120 

Hazara, 29 

Himachalene, 66 

Hong Kong, trade, 154, 157, 161, 164 

Hormones, activation of, 91 

Humulene, 66–67 

Hungary, trade, 154, 157 

Hyderabad, 30 

Hyphenated analysis techniques, 198–203 

13 C NMR, 200–201 

enantiomeric differentiation, 201–202 

GC-FTIR, 200 

GC-MS, 198–199 

GC-MS combined with GC(RI), 198–199 

GC-MS-FTIR, 200 

GC-MS-MS, 199–200 

GcxGC-MS, 199 

HPLC-GC-MS, 200 

HPLC- 1 H NMR, 200 

HPLC-MS, 200 

two-step procedure, 202–203 

I 

Iceland, trade, 157 

Immunolocalization, rubisco, 7 

In vitro antimicrobial, antioxidant activities, 167–183 

agar diffusion method, 170 

alpha tocopherol, 179 

citral, 179 

citronellal, 179 

citronellol, 179 

Cymbopogon citratus, 179 

Cymbopogon nardus, 179 

essential oil-solubilizing agents, 168 

factors affecting antimicrobial activity, 168–177 

factors affecting antioxidant activity, 178–180 

geraniol, 179 

gram-negative bacteria, 169 

gram-positive bacteria, 169 

limonene, 179 

media, 178–179 

methods used for antimicrobial assessment, 170–177 

mould, 169 

oil components, activity, correlation between, 169–170 

oxidation conditions, 179–180 

oxidizable substrate, end-product evaluation, 178 

serial broth dilution method, 170 

solubilizing agents, 168–169 

testing antioxidant activity, 180 


diphenyl-1-perylhydrazyl free radicals scavenging 

test, 180 


type of organism, 169 

vapor contact assay, 170–177 

yeast, 169 

India, 30–31 

Indian Standards Institution, 29–30 

Indonesia, trade, 154, 157, 160–161 

The International Plant Names Index, 2–3 

Iran, trade, 157 

Ireland, trade, 154, 157, 164 

ISI. See Indian Standards Institution 

Isoborneol, 55 

Isopiperitenone, 47 

Isopulegol, 47 

Israel, trade, 154, 157, 161 

Italy, trade, 154, 157, 160–161 

J 

Jamaica, trade, 157 

Jammu, 30 

Japan, trade, 154, 157, 161, 164 

Java, 30–32 

Java, 228 

Jordan, trade, 157 

Jorhat, 32 

K 

Kenya, trade, 157, 161 

Kerala, 28 

Kordofan Sudan, 34 

Korea, trade, 157, 161 

Kumaon, 28, 32 

Kuwait, trade, 157 

l 

Latvia, trade, 157 

Lavandulol, 38 

Leaf anatomy, Cymbopogon genus, 5–7 

Lemon oil, 228

Index 243 

Lemongrass, 68–71, 109–117, 153–162, 228 

citral from, 223–237 

analysis methods, 230–231 

classification, 234–235 

dose rate, 227 

IFRA classes, product types, 234 

labeling, 234–235 

lemongrass oils, 229–230 

Litsea cubeba oil, 227–229 

manufacturing methods, 230 

natural citral sources, 228 

natural sources, 227–230 

RIFM, 231–234 

safety data sheets, 235 

toxicology, 231–234 

uses, 227 

distillation, 113–115 

condensers, 114 

oil separators, 114–115 

steam boiler, 114 

stills, 114 

drying, 113 



predistillation handling, 112–113 

quality analysis, 116–117 


storage, 113 

supercritical fluid extraction, 115–116 

treatment of oil prior to storage, 116 

purification of oil, 116 

storage and packing of oil, 116 

yield, 112–116 

Leukemia, activity against, 91 

Lime oil, 228 

Limonene, 41, 179 

Limonene oxide, 48 

Linalool, 39 

Linalyl acetate, 39 

Lippia citriodora, 228 

List of Cymbopogon species, 2–3 

Litsea cubeba oil, 228 

Longifolene, 67 

Lowering blood sugar, 91 

Lucknow, 28, 30, 32 

m 

Madras, 30 

Malabar District, 33 

Malaysia, trade, 154, 157 

Maldives, trade, 157, 161 

Male hormones, activation of, 91 

Malignancy, activity against, 91 

Mass spectrometry with gas chromatography, analysis by, 

206 

Mauritius, trade, 157, 162 

Menthene-3-one, 48 

Menthol, 48 

Menthone, 49 

Menthyl acetate, 48 

Metabolic engineering studies, 141–142 

Methods used for antimicrobial assessment, 170–177 

Methyl thymyl ether, 50 

Mexico, trade, 157, 162, 164 

Microbes, activity against, 93–95 

Molecular biology, Cymbopogon genus, 1–24 

randomly amplified polymorphic DNA markers, 11–13 

simple sequence repeat markers, 13 

Monoterpenes in cymbogon essential oils, 35–56 

Mosquitoes, potential to repel, kill larvae, 91–92 

Mould, 169 

Mozambique, trade, 157 

Murrolene, 67 

Myanmar, trade, 157 

Myrcene, 41 

Myrtenol, 55 

n 


Nainital, 32, 34 

Nepal, trade, 154, 157, 162 

Nerol, 39, 228 

Neryl acetate, 39 

Netherlands, trade, 155, 157, 162, 164 

New Caledonia, trade, 157 

New Zealand, trade, 157, 162, 164 

Nigeria, trade, 157 

Nilgiri Hills, 31 

o 

O-cymene, 40 

Odakali, 28, 31 

Oil components, activity, correlation between, 169–170 

Oman, trade, 157, 162 

Orange bitter oil, 228 

Orange sweet oil, 228 

Oxidation conditions, 179–180 

Oxidizable substrate, end-product evaluation, 178 

Oxygenated monoterpenes, 44–53 

P 

P-cymene, 40 

P-menth-2,8-dien-1-ol, 50 

P-menth-2-en-1-ol, 49 

P-menth-8-en-1-ol, 49 

Pain relievers, 89–91 

Pakistan, trade, 157 

Palmarosa, 160–164 

and gingergrass oils, 73–74 





storage, 119 

uses, 118 

yield, 119–120 

Panama Republic, trade, 157 

Pantnagar, 28, 32 

Paraguay, trade, 155, 157 

Perillaldehyde, 50

244 Index 

Perillene, 51 

Perillyl alcohol, 51 

Peru, trade, 157 

Pests, activity against, 93 

Petitgrain bergamot oil, 228 

Petitgrain bitter orange oil, 228 

Petitgrain lemon oil, 228 

Petitgrain mandarin oil, 228 

Phellandrene, 35 

Philippines, trade, 157, 162 

Photosynthetic variant characterization, 8–9 

Phylogenetic studies, 139–140 

Physicochemical characteristics, 26–67 

Physiochemical properties, 28–34 

Physiology, Cymbopogon genus, 1–24 




Pinene, 43 

Piperitenone, 51 

Piperitone, 52 

Piperitone oxide, 52 

Platelet aggregation test, 189 

Poland, trade, 155, 158 

Postharvest management, Cymbopogons. See Harvest/ 

postharvest management 

Pulegone, 53 

r 

Randomly amplified polymorphic DNA markers, 11–13 

RAPD markers. See Randomly amplified polymorphic 

DNA markers 

Reunion, trade, 158 

Romania, trade, 158 

Rose oil, 228 

Rubisco immunolocalization, 7 

Russia, trade, 158 

Rwanda, trade, 158 

s 

Sabienene, 43 

Saudi Arabia, trade, 158 

Serial broth dilution method, 170 

Sesquiterpenes in Cymbopogon oils, 57 

Simple sequence repeat markers, 13 

Sind, 29 

Singapore, trade, 155, 158, 160, 162, 164 

6,7-epoxy-3,7-dimethyl-1,3-octadiene, 46 

6-methylhept-5-en-2-one, 40 

Slovenia, trade, 155, 162 

South Africa, trade, 158, 162, 164 

Spain, trade, 155, 158, 160, 162, 164 

Sri Lanka, trade, 155, 158, 162 

SSRs. See Simple sequence repeat markers 

Standard fibrin plate method, 186 

Subspecies, Cymbopogon, 2–3 

Subvarieties, Cymbopogon, 2–3 

Sudan, trade, 158 

Sugar, blood, lowering of, 91 

Surinam, trade, 162 

Swaziland, trade, 155 

Switzerland, trade, 155, 158, 162, 164 

Syria, trade, 158 

t 

Taiwan, trade, 158, 162, 164 

Tanzania, trade, 155, 158, 162, 164 

TBARS assay. See Thiobarbituric acid reactive substance 

assay 

Temperature dependence, NADPH-MDH, NADP-ME, 

9–10 

Temperature dependence of NADPH-MDH, NADP-ME, 

9–10 

Terpenes in Cymbopogon species, 79–84 

Terpin-4-ol, 53 

Terpinene, 41–42 

Terpineol, 53 

Terpinolene, 42 

Testing antioxidant activity, 180 


diphenyl-1-perylhydrazyl free radicals scavenging test, 

180 


Thailand, trade, 155, 158, 162, 164 

Thiobarbituric acid reactive substance assay, 180 

Thrombolysis acceleration, 185–194 

blood coagulation activity, 189 

euglobulin, 186–187 

in vivo fibrinolytic activity, 189 

fibrin plate method, 186–187 

platelet aggregation test, 189 

standard fibrin plate method, 186 

tissue plasminogen activator-producing cells, 188 

Thujene alcohol, 55 

Thujyl alcohol, 55 

Tissue culture studies, 137–139 

Tissue plasminogen activator-producing cells, 188 

Trade, 151–165 

Trans-isopiperitenol, 47 

Trans-ocimene, 35 

Trans-piperitol, 52 

Travancore, 29 

Tunisia, trade, 158 

Turkey, trade, 158 

u 

UAE, trade, 155, 158, 164 

Uganda, trade, 158 

U.K., trade, 155, 158, 160, 162 

Ultrastructure, Cymbopogon citratus leaf, 7 

Uruguay, trade, 155 

U.S., trade, 155, 158, 160, 162, 164 

Uses of Cymbopogon essential oils, 68–95 

V 

Vapor contact assay, 170–177 

Varieties, Cymbopogon, 2–3 

Verbena, 228

Index 245 

Verbenone, 56 

Vietnam, trade, 155, 162 

W 

West Bengal, 28, 30, 32 

World demand, 152–153 

Worms, activity against, 91 

y 

Yeast, 169 

Yemen, trade, 158, 162 

Z 

Zambia, trade, 158

Essential Oil- Bearing Grasses

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