Journal of Ethnopharmacology, Elsevier Scientific Publishers 233 24 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJI (1988) 233-246 Ireland Ltd. WHEAT ROOTLET GROWTH INHIBITION TEST OF RWANDESE MEDICINAL PLANTS: ACTIVE PRINCIPLES OF zyxwvutsrqponmlkjihgfedcbaZ TETRADENIA RIPARIA AND DIPLOLOPHIUM AFRICANUM LUC VAN PUYVELDE”, NORBERT DE KIMPE’, JEAN COSTAb, PROSPER NSHIMYUMUKIZAb, HAKIZAMUNGU” and NICEAS SCHAMP’ F’RANCOIS-XAVIER AYOBANGIRA” YVES BOILY”, ETIENNE “Centre Universitaire de Recherche SW la Pharmacopke et la Mkdecine Tmditionnelle CURPHAMETRA, Universite’ Nationale du Rwanda, B.P. 117 Butare, bDt!partement de Chimie, Faculti des Sciences, Universiti Nationab du Rwanda, B.P. 117 Butare (Rwanda) and ‘Laboratoy of Organic Chemistry, Faculty of Agricultural Sciences, State University of Gent, Coupure Links 653, B-9000 Gent (Belgium) (Accepted July ZOth, 1988) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDC Summary A series of 50 medicinal plants of Rwanda (121 plant samples) has been screened for wheat rootlets inhibition activity. The minimum inhibitory concentration (MIC) of the active principle of Tetradenia riparia, i.e. 8( 14), 15sandaracopimaradiene-7 cy, l&diol (7.81 pglml), and of the active principle of Diplolophium africanum, i.e. scoparone (62.5 pg/ml), in this test was determined. Introduction In order to find Rwandese medicinal plants with antimitotic activity we used a preliminary test inspired by the method of Ceriotti (1965), i.e. the inhibition of the growth of the rootlets of wheat (Boily and Harelimana, 1979). A series of 50 plants (121 plant samples) were screened in this test. Plants were chosen among well known medicinal plants of the Rwandese native medicine (Table 1) (Van Puyvelde et al., 1975, 1977a, 1977b, 1982). The plant powders were first tested at a concentration of 100 mglml. Afterwards, tests at a concentration of the plant powders of 10, 5 and 1 mg/ml were performed with the plants showing an inhibition of the growth of the rootlets of 90% or more at the concentration of 100 mg/ml. 0378-8741/88/$05.25 @ 1988 El sevier Scientific Published and Printed in Ireland Publishers Ireland Ltd 234 TABLE 1 MEDICINAL PLANTS Family, botanical ACANTHACEAE USED IN THE RWANDESE name Folk name NATIVE MEDICINE Plant Disease, use parts” zyxwvutsrqponmlkjihgfedcbaZYXW zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Igihapfu Ikirogora Magaru L L Leprosy, vermifuge, emetic, eczema, snakebite, lactogen Jaundice Ijojwe L Skin diseases Gutwikumwe Agaso W.PL. PL Surgery Poison Igihondogoro L To favor& placenta Aspilia africana (Pers.) C Adams Icyumwa L Car&us lepthucanthus Fresen. Crassocephulum nwntuosum @Moore) Milne-Redh. Elephantopus plurisetus (0. Hoffm.) Clonts Senecio mnmglrensis 0. Hoffm. Vernonia hochstetteri A. Rich Mugabudasumirwa Igifuraninda W.PL. Anthrax, gonorrhea, syphilis, yaws, pneumonia, leprosy, malaria, epilepsy, antiseptic Snakebite L Leprosy, Igisharakisi Igihuna Imbatura PL Gastroenteritis L Yaws, Ikonambogo L Anthrepsis Indondoli L To benefit the uterine contractions Yaws Brillantnisia cicatricosa Lindau Hypoestes trifkv-a (Forssk.) Roem. et Schultes Justicia flaua (Vahl)Vahl APIACEAE Centellu asiatica (L.) Urb. Diplolophium africanum Turcz. ARALIACEAE Cussonia arborea Hochst. A.Rich. ex. the delivery of the ASTEXACEAE malaria syphilis BALSAMINACEAE Zmpatiens burtonii Hook. f. R BASELLACFXE Basella alba L. Indarama W.PL. Snakebite, to facilitate childbirth Umukoli L Jaundice Umukubagwa R Umushishi R Scabies, eczema, asthma, leprosy, gastroenteritis Cosmetic Umurama L Snakebite, BIGNONIACEAE Markhnmia obtusifolia (Baker) Sprague CLUSIACEAE Psorospermum febrifugum Spach Symphonia globulifem L.f. COMBRETACRAE Combreturn nude R.Br. ex G. Don cough 235 zyxwvut TABLE 1 (Continaecf) Family, botanical name Folk name Plant Disease, use parts” zyxwvutsrqponmlkjihgfedcbaZYXW Mugogutarengwa PL Snakebite Ikiduha LA Gonorrhea, dysentery, angina, vermifuge, tonicum Umuhashya Igitembatembe Amakubwe L+s L FR R Rectal prolapse, abcess To benefit the uterine contractions Malnutrition Female frigidity W.PL. Jaundice, CYATHEACEAE Cyathea monniana Hook EUPHORBIACEAE Euphorbia candelabrum Welw. FABACFAE Dalbergia la&tea Vatke Neorautanenia mitis (A. Rich.) Verde. HYDNORACEAE Hydnora johanis Beccari Umutima w’isi cardiotonicum LAMIACEAE Plectranthus lariflorus Benth. Pycnostnchys erici-rosenii Rwagara Cough, wounds, abscess Cough Umutsinduka breast R.E. Fries Angina, yaws, gastroenteritis, Umuravumba antiseptic, phagedenic Codd zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ulcer, toothache, malaria, female sterility, conservation of the foodstuff R Gonorrhea BR Bronchitis, diarrhea ‘Z’etradenia riparia (Hochst.) LAURACEXE Ocotea michekonii Rob. et Umuganza BS Whipworm Umushabishabi L,R Vermifuge Intomvu W.PL. R Cardiotonicum Counterpoison Umunyu w’intama L Herpes, yaws, wounds, epilepsy Sprague Umus hwati L Wounds Fresen. Umukaka L Whipworm, Mumeya BR Ifumbib Wilcz. LILIACRAE Asparagus falcatus L. LOBELIACEAE Lobelia petiolcrta Hauman MELASTOMATACEAE Dissotis b llzzzne cogn. MELIACEAE Campa gmndifkva MELIANTHACRAE Bersama abyssinica MENISPERMACEAE Albertisia Forman exelliana (Troupin) ascaris, diarrhea 236 TABLE 1 (Continued) Family, botanical MIMOSACEAE name Folk name Disease, use Plant parts” zyxwvutsrqponmlkjihgfedcbaZYXW zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Acacida mearnsii De Wild. Albizia adianthifolia @chum.) W.F. Wight Barakatsi L Umusebeya Leprosy Cough, jaundice, ozena anthrax, MYRICACEAE Myrica knndtiana Engl. Isubyu Umusengesi PI, Anal and vaginal prolapse, anthrax, smallpox, counterpoison Umugote L,BS Cough Umubanga L Cough Ikibundi L Poliomyelitis Umunyagasozi Umukuyu L Abortifacient, snakebite Rheumatism, toothache, malnutrition, ifumbi” MYRTACEAE Syzygium cordatum Hochst. ex Sonder OLEACEAE ,Schrebera alata (Hochst.) Welw. PIPERACEAE Piper capense L. f POLYGALACEAE Securiahca longepedunculata Fresen. R POLYGONACEAE Umulyanyoni PL Wounds, Umugeshi 1, Vermifuge, Umutanoga Umushabarara L BS Cough, ascaris Ascaris Umutana L Pneumonia, Solanum anguivii Lam. Igitagarasolyo FR Solanum indicum L. Solanum nigrum L Igitagarasolyo Isogo PL L Abcess, anthrax, amebic dysentery Taenifuge, toothpaste Lactogen Umugosora L Ascaris, Polygonum setosulum Hochst ex A. Rich burns, snakebite ROSACEAE Hagenia abyssinica (Bruce) J.F. Gmelin cosmetic RUBIACEAE Fadogia ancylanth Hiern. Rytigynia beniensis (De Wild.) Robyns RUTACEAE Clausena anisata (Willd.) Hoof. f. ex Benth. sterility 30LANACEAE JFXBENACEAE Verbena ofiinalis L. leprosy 237 TABLE 1 (Continued) Family, botanical name VI’I‘ACEAE Folk name Plant Disease, use parts” zyxwvutsrqponmlkjihgfedcbaZYXW zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Rhoicissus tridentata (L.f .) Igitongoro BS Gastro-intestinal pain Wild. et Drum. “L, leaf; S, stem; R, root; FR, fruit; LA, latex; BR, bark of the root; RB, root without bark; BS, bark of the stem; PL, plant without roots; W.PL., whole plant. “Ifumbi: illnesses not identified by the traditional healer. This illness can attack each part of the body and causes neuralgia, headache, imaginary pregnancy, abortion and deficient milk production. Some traditional healers think it is a hereditary illness. zyxwvutsrqponmlkjihgfedcba The leaves of ~etr~nia riparia and the roots of D~p~~~phium africhosen for further investigation. Bioactivity-guided fractionation and chromatography has led to the isolation of the active principles. Tetradenia riparia (Hochst) Codd. (Lamiaceae) is an important medicinal plant in the native medicine of Rwanda, where it is known under the name of umuravumba. The plant is used as a remedy against a wide range of diseases including malaria, angina, yaws, anthelmin~s-induced diseases, gastroen~ritis, gonorrhea, diarrhea, dental abcesses, headache and several kinds of fevers and aches (Van Puyvelde et al., 1975, 1976). Diplolophium africanum Turcz. (Apiaceae) is named agaso in Rwanda while the plant is known in East Africa to be toxic for cattle (Watt and Breyer-Brandwi j k, 1962). cunum were Material and methods Plant ~teria~ Plants were collected and identified by one of the authors (F.X. Ayobangira). Voucher herbarium species are preserved in the herbarium of the Department of Botany (CURPHAMEI’RA). Plant parts were air-dried and afterwards powdered mechanically. Biological utility Grains of wheat were preliminary germinated in tape water during 24 h in the dark. Afterwards, 10 grains were put on a filter-paper (Whatman no. 1, diameter 9 cm) in a Petri dish (diameter 10 cm) containing 10 ml of tap water and 1000 mg of the plant powder (concentration 100 mglml). The Petri 238 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA dishes were then kept in the dark at ambiant temperature and the growth of the rootlets was evaluated after 6 days. The inhibition of the growth of the rootlets is given in per cent compared with the growth of the rootlets of non-treated grains under the same conditions (expressed as the mean of 10 grains). For the plant powders which showed an inhibition of 90% or more on the growth of the rootlets, further dilutions were tested at 10, 5 and 1 mglml. The biological test was used during the whole isolation procedure of the active principles of 2’. riparia and D. africanurn. The fractions were dissolved in acetone at a concentration of 50 mg/ml. This acetone solution (0.2 ml) was mixed with 9.8 ml of tap water in a Petri dish to obtain a final concentration of 1 mglml (2% acetone in water showed no effect on the growth of the rootlets). For the active principles, the minimum inhibitory concentration (MIC) values were determined as the lowest concentration of the compound which completely inhibited (100%) the rootlets of wheat. zyxwvutsrqp Isolation of active principles T. riparia: a sample of 1000 g of the powder of the leaves was extracted in a percolator with 151 chloroform. The chloroform extract was concentrated under reduced pressure (40°C) yielding a green residue (135 g). The extract (18 g) was chromatographed over a silica gel column (600 g; Merck, 230-400 mesh) using a benzene/chloroform/methanol gradient 8(14),151) was isolated with chloroSandaracopimaradiene-7 (Y,18-diol (Fig. form/methanol (97:3) to afford 1.2 g (0.9% of dry plant) and was recrystallized from benzene giving colourless crystals (m.p. 86-87°C) (De Kimpe et al., 1982). D. africanum: a sample of 180 g of the power of the roots was first extracted in a percolator with petroleum ether (40”-6o”C) (0.81) and then with chloroform (41). The chloroform extract was concentrated under reduced pressure yielding a yellow residue (15.5 g). The residue was dissolved again in chloroform and extracted with methanol-water (1: 0.75). Fig. 1. Structure of 8(14),15-sandaracopimaradiene-7u,l8-diol. 239 zyxwvu Fig. 2. Structure of scoparone. Both phases were concentrated to dryness under reduced pressure yielding a chloroform residue (14.7 g) and a methanol/water residue (0.8 g). The chloroform residue (14.7 g), absorbed on 75g silica gel, was chromatographed over a silica gel column (525g; Merck 230400mesh) using a petroleum/ether (40”-6O”C), benzene, chloroform, methanol gradient. Scoparone (Fig. 2) was isolated with CHCl,-MeOH (97 : 3) to afford 4.31 g (2.4% of dry plant) and was recrystallized from acetone giving white crystals, m.p. 145”-146°C (lit. m.p. 144”-146°C; Murray, 1978). IR (KBr): 1700 cm-’ (broad, strong; vc-); 1610 cm ’ (medium vc&. ‘H-NMR (CDC13: 3.91 and 3.93 (each 3 H; each s, 2 x OMe); 6.25 (1 H, d, J =9.4Hz, =CH(3)); 7.60 (lH, d, J=9.4Hz, = CH(4)); 6.80 and 6.85 (each 1 H, each s, = CH(5) and = CH(6)). 13C-NMR (CDC13): 56.35 (q; both methoxy signals at C(6) and C(7) overlap completely); 161.3 (s, C = 0); 113.4 (d, = CH(3)); 114.4 (s, = C(4a)); 143.3 (d, = CH (4)); 99.9 (d, = CH (8)); 108.2 (d, = CH(5)); 146.3 (s, = C(6)); 150.0 (s, = C(8a)); 152.9 (s, = C(7)). These 13C-NMR values fit very well with the 13C-NMR values of the 6,7-dihydro analogue, i.e. 6,7-dihydroxycoumarine (Chang and Floss, 1977) and agree with data reported for 6-methoxycoumarine and 7-methoxycoumarine (Gottlieb et al., 1979). Mass spectrum (70 eV): m/e 206 (M+, 100%). UV (MeOH): A,,, 268 nm. zyxwvuts Results and discussion Of 121 plant samples tested (50 plants), 23 showed an inhibitory effect of 90% or more on the rootlets of wheat (Table 2) at a concentration of 100 mg/ml. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Tetradenia riparia and Diplolophium africanum were chosen for further investigation as they showed the greatest inhibitory effect. Tetradenia riparia Besides the rootlets inhibitory activity, a substantial antimicrobial (Boily and Van Puyvelde, 1986; Van Puyvelde et al., 1986) and antispasmodic activity (Chagnon, 1985; Van Puyvelde et al., 1984, 1987) was found in the leaves. This led to the isolation of a diterpenediol (Fig. l), i.e. 8(14),15sandaracopimaradiene_7a, 18-diol (De Kimpe et al., 1982). Several other 240 TABLE 2 INHIBITION MEDICINAL OF THE GROWTH PLANTS Family, botanical OF THE ROOTLETS name Coil. no. OF WHEAT Plant parts” BY RWANDESE % inhibition at concentration of plant powder (mg/ml) 100 10 1 zyxwvutsr 5 ACANTHACRAE Brillantaisia cicatricosa 183 Lindau Hypoestes triflora (Forssk.) 305 Roem. et Schultes Justicia /lava (Vahl) Vahl 164 L S R L S L S FR 97 64 14 100 52 91 93 84 W.PL S R 75 68 - 50 43 - 30 - 40 33 - 22 15 - - 71 33 100 - - - 100 96 86 L S FL 51 57 81 - - - S R L S R L S FR PL R L S L S R 33 45 86 82 55 95 67 49 63 98 73 17 100 13 16 - - - - 3 APIACEAE Centelhz asiatica (L.) Urb. Diplolophium africanurn Turcz. 173 281 ARALIACEAE Cussonia arborea Hochst - ex 219 A. Rich. ASTERACEAE Aspilia africana (Pers.) C. Adams 210 Carduus Leptacanthus Fresen. 257 Crassocephalum nwntuosum (S. Moore) 177 Milne - Redh. Elephuntopus plurisetus (0. Hoffm.) 250 Clonts Senecio maranguznsis 0. Hoff m. 172 Vernonia hochstetteri A. Rich. 243 6 11 2 - - 46 - - - 20 - - - - - 4 63 43 - - 49 38 6 4 BALSAMINACEAE Zmpatiens burtonii Hook. f. 128 L S 30 54 180 L S 100 93 L S 58 71 BASELLACEAE Base& alba L. 91 77 - BIGNONIACEAE Markhnmia obtusifolia Sprague (Baker) 248 - 241 zyxwvut TABLE 2 (Continued) Coll. no. Family, botanical name Plant parts” % inhibition at concentration of plant powder (mglml) 106 CLUSIACEAE Sprach Psorospermum febrifugum Symphonia globulifera L.f. 1 zyxwvutsr 5 10 L S L S BR RB 71 66 82 0 79 32 - - - 227 L 83 75 - - - 174 L S 67 73 - - - 134 PL 65 - - - L S L S R 69 56 92 69 99 - - - 37 48 25 36 270 W.PL 76 - - - 198 L S L S L S R 100 79 76 18 100 33 75 100 100 - 41 97 - 7 95 - 311 I, S R 89 32 69 - - - 185 L S 60 51 - - - 269 L S 81 92 - 39 38 237 211 COMBRLWACRAE Combreturn malls R.Br. ex G. Don CYATHEACEAE Cyntheu ~nn~ana Hook EUI’HORBIACEAE Eupharbia candelabrum Welw FABACEAE Vatke Dalbergia &tea mitis (A. Rich.) Neorautanenia Verde. 92 223 51 57 HYDNORACEAE Hydnora johannis Beccari LAMIACEAE Plectmnthus laxiflorus Benth. Pycnostachys erici-rosenii R.E. Fries Tetma!enia riparia (Hochst.) Codd 151 1 LAURACEAE Ocotea micheLsonii Robyns et Wilczek LILIACEAE Asparagus fa~at~ L. LOBELIACEAE Lobelia petiolata Hauman 49 242 TABLE 2 (Continued) Family, botanical Cell. no. name Plant parts” Q inhibition at concentration of plant powder (mglml) 100 10 1 zyxwvutsrq 5 MELASTOMATACEAE 196 L S 75 71 - - - Sprague 203 L S 79 69 - - - Fresen. 233 L S 61 71 - - - 300 L s 74 36 - - - Acacia mearnsii De Wild. 149 Albizia adianthifolia 273 L S R L SB BS a2 82 83 68 98 30 - - - - 52 - - 131 S R BS SB 71 81 80 29 - - - 216 L S 80 78 - - - 249 L S R 89 32 69 - - - 294 S R 81 96 - - - 84 87 100 67 - - - 100 - 96 - 82 - brazzae Cogn Ihsotis MELIACEAE &nqm grandifha MXLIANTHACEAE Bersama abyssinica MENISPERMACEAE Albertisia exefliana (Troupin) Forman MIMOSACEAE @chum.) W.F. Wight 84 3 MYRICACEAE Myricu kandtiana Engl MYRTACEAE Syzygium cord&urn Hochst. ex Sonder OLEXCEAE Schreberu al&a (Hochst.) Welw PIPERACEAE Piper capense L.f 54 21 0 POLYGALACEAE Securidaca ~gepe~u~cu~~ Fresen. 240 L S BR RB 243 TABLE 2 (Continued) Family, botanical Coil. no. name Plant partsa 5%inhibition at concentration of plant powder (mglml) 100 POLYGONACEAE 10 1 zyxwvutsrq 5 195 L s 81 75 - - - (Bruce) 150 L S R 61 67 66 - - - Hiern 214 (De Wild.) 236 75 48 63 21 33 - - - 100 18 88 - 85 - 77 - 80 15 - - 83 - 71 17 - Hochst. Polygonum setosulum ex A. Rich. ROSACEAE Hagenia abyssinica J.F. Gmel. RUBIACEAE Fadogia ancylan Rytigynia Robyns th beniensis RUTACEAE Clausena anisata (Willd.) Hook. f. ex Benth. 218 L S SOLANACEAE Solanum anguivii Solanum indicum Solnnum nigrum Lam. L S FR L S FR L S 98 37 93 40 60 91 97 35 - 76 80 - 274 L BS SB 85 65 75 - - - 234 L S R 57 63 61 - - - 346 L 324 L. 163 92 82 93 3 6 VEZRBENACEAE Verbena ofiinalis L. VITACEAE Rhoicissus trident&n Wild et Drummond (L.f.) “L, leaf; S, stem; R, root; FR, fruit; PL, plant without root; BR, bark of the root; RB, root without bark; BS, bark of the stem; SB, stem without bark. 244 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA compounds were isolated from the leaves, including ibozol, 7 cy-hydroxyroyleanone (Zelnik et al., 1978), umuravumbolide, deacetylumuravumbolide, deacetylboronolide (Van Puyvelde et al., 1979), 1’,2’-dideacetylboronolide (Van Puyvelde et al., 198 1) and 8( 14), 15-sandaracopimaradiene-2 a, 18-diol (Van Puyvelde et al., 1987). The inhibitory effect of the diterpenediol, 8(14),15sandaracopimaradiene7(r, 18-diol on the growth of the rootlets of wheat was determined. A MIC value (minimum inhibitory concentration) of 7.81 pg/ml was found. zyxwvutsrqpon Diplolophium africanurn The compound responsible for the inhibitory effect on the growth of the rootlets of wheat was isolated from the chloroform extract of the roots after column chromatography on silica gel. The structure of the active principle was determined by spectrometric methods, including ‘H-NMR, 13C-NMR, IR and MS and identified as scoparone (Fig. 2). The inhibitory effect on the growth of the rootlets of wheat for scoparone was determined and a MIC-value of 62.5 Kg/ml was found. This is the first time that scoparone was isolated from Diplolophium africanum and that the inhibitory effect on the growth of the rootlets was determined. The occurrence of coumarins in plant sources is widespread as evidenced from a recent coverage of the literature in this area (Murray et al., 1982). Scoparone (6,7-dimethoxycoumarine or 6,7-dimethoxy-2Ij-l-benzopyran‘L-one), also named escoparone, is a frequently occurring coumarin derivative in plant sources. Some of the natural sources from which scoparone was isolated include Artemisia scoparia (Ban’kovskaya and Ban’kovskii, 1959; Nesmelova and Sidyakin, 1971), Ferula oopoda (Kir’yalov and Serkerov, 1965), Custanea crenata (Kurogi and Uritani, 1965), Afraegle paniculata (Adesogan, 1973), Achilles filipendulina (Sham’yanov et al. 1974), Angelica pachycarpa (Mendez and Rubido, 1979), Angelica dahurica (Kozawa et al., 1981), Zanthoxylum coreanum (Kim and Huh, 1981) and Zanthoxylum William&i (Stermitz et al., 1980). The biological activity of scoparone has been studied several times and for instance this dimethoxylated coumarine was found to display hypotensive and tranquilizing activity in laboratory animals and to cause peripheral vasodilation, antispasmodic and relaxant action on the smooth muscle (Jamwal et al., 1972, Thakur et al., 1978). In addition a pharmacokinetic study was undertaken recently (Yamahara et al., 1981). The MIC-values of the reference compounds in this test were 125 pglml for colchicine and 500 pg/ml for podophylline. It seems, that substances with antimitotic activity in animal cells do not always have a similar activity in vegetal cells; thus the conclusion for our two active principles to have antimitotic activity is irrelevant. Nevertheless, t,his simple biological test, can be used for isolating active 245 zyxwvu principles: the diterpenediol which was also responsible for the antispasmodic and antimicrobial activity of T. riparia and the coumarine isolated from D. africunum which was found to display several biological activities. zyxwvuts Acknowledgement The authors are indebted to the Belgian Administration and Cooperation for financial support. for Development References Adesogan, E.K. (1973) Coumarins and other components of Afmegle paniculata. Phytochemistry 12(g), 2310-2312. Ban’kovskaya, A.N. and Ban’kovskii, A.I. (1959) Chemical study of Artemisia scoparia. Trudy Vsesoyus, Nauch.-lssledovated. Inst. Lekarstv.i Aromat. Rast. 11, 177-9 (cited in Chemical Abstracts 55 (1961) 17776~). Boily, Y. and Harelimana, E. (1971), Des substances antimitotiques et contre le cancer dans les plantes medicinales du Rwanda. Etudes Rwandaises XIII, 1, 14-26. Ceriotti, G. 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