Cembranolides from the leaves of Croton gratissimus

Ten new cembranolides, (-)-(1R*,4R*,10R*)-4-methoxycembra-2E,7E,11Z-trien-20,10-olide (1), (-)-(1S*,4R*,10R*)-1-hydroxy-4-methoxycembra-2E,7E,11Z-trien-20,10-olide (2), (-)-(1S*,4S*,10R*)-1,4-dihydroxycembra-2E,7E,11Z-trien-20,10-olide (3), (-)-(1S*,4S*,10R*)-1,4-dihydroxycembra-2E,7E,11Z-trien-20,10-olide (4), (+)-(10R*)-cembra-1E,3E,7E,11Z,16-pentaen-20,10-olide (5), (+)-(10R*)-cembra-1Z,3Z,7E,11Z,15-pentaen-20,10-olide (6), (+)-(5R*,10R*)-5-methoxycembra-1E,3E,7E,11Z,15-pentaen-20,10-olide (7), (+)-(1S*,4S*,7R*,10R*)-1,4,7-trihydroxycembra-2E,8(19),11Z-trien-20,10-olide (8), (-)-(1S*,4S*,7S*,10R*)-1,4,7-trihydroxycembra-2E,8(19),11Z-trien-20,10-olide (9), and (+)-(1S*,4R*,8S*,10R*)-1,4,8-trihydroxycembra-2E,6E,11Z-trien-20,10-olide (10), together with six known compounds, lupeol, 4(15)-eudesmene-1β,6α-diol, α-glutinol, 24-ethylcholesta-4,22-dien-3-one, (+)-(1R*,10R*)-cembra-2E,4E,7E,11Z-tetraen-20,10-olide, and (+)-(1R*,4S*,10R*)-4-hydroxycembra-2E,7E,11Z-trien-20,10-olide (4a), have been isolated from the leaves of Croton gratissimus. The acetyl derivatives of 8 and 4a were evaluated against a chloroquine-sensitive strain of Plasmodium falciparum (D10).     

New dihydrophenanthrene and phenyldihydroisocoumarin constituents of Trema orientalis.

In the course of the chemical investigation of extracts of the trunk bark and root bark of Trema orientalis, three new compounds were isolated, namely, (9S*,10S*)-3-[7-(3,10-dihydroxy-9-hydroxymethyl-2,5-dimethoxy)-9,10-dihydrophenanthrenyl]propenal (1), (9S*,10S*)-3-[7-(5-O-beta-glucopyranosyl-10-hydroxy-9-hydroxymethyl-2,6-dimethoxy)-9,10-dihydrophenanthrenyl]propenal (2), and (3R*,3aR*,4R*,5S*)-6-O-alpha-arabinopyranosyl-8-hydroxy-3-(4-hydroxyphenyl)-4-(4-hydroxyphenyl)-5-(3,5-dihydroxyphenyl)-3,3a-dihydrocyclopenta[1,2,3-de]isobenzopyran-1-one (3, orientoside A). The structures of 1-3 were determined by spectral methods.     

Cytotoxic dolabellane diterpenes from the Formosan soft coral Clavularia inflata

Six new cytotoxic dolabellane diterpenes, (1R,12R)-dolabella-4(16),7,10-triene-3,13-dione (1), (1R*,7R*,8S*,12R*)-dolabella-4(16),10-diene-7,8-epoxy- 3,13-dione (2), (1R*,10R*,11S*,12R*)-dolabella-4(16),7-diene-10,11-epoxy-3,13-dione (3), (1R)-dolabella-4(16),7,11(12)-triene-3,13-dione (4), (1R*,3R*)-3-hydroxydolabella-4(16),7,11(12)-triene-3,13-dione (5), and (1R*,7R*)-7-hydroperoxydolabella-4(16),8(17),11(12)-triene-3,13-dione (6), have been isolated from the Formosan soft coral Clavularia inflata. The structures of compounds 1-6 were determined by 1D and 2D spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.     

Beesiosides G, H, and J-N, seven new cycloartane triterpene glycosides from Beesia calthifolia

Seven new cycloartane glycosides (1-7), beesiosides G, H, and J-N, together with beesioside I (8) and beesioside A, were isolated from the rhizomes of Beesia calthifolia, and their structures were established by spectroscopic and chemical methods. Beesiosides G, H, and J-N were assigned as 20xi(1),24xi(2)-epoxy-9,19-cyclolanostane-3beta,16beta,18,25-tetraol-3-O-beta-D-glucopyranoside (1), 20xi(1),24xi(2)-epoxy-9,19-cyclolanostane-3beta,16beta,18,25-tetraol-3-O-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (2), (20S,24R)-15alpha,16beta-diacetoxy-20,24-epoxy-9,19-cyclolanostane-3beta,18,25-triol-3-O-beta-D-xylopyranoside (3), (20S,24S)-16beta-acetoxy-18,24;20,24-diepoxy-9,19-cyclanostane-3beta,15beta,25-triol-3-O-beta-D-xylopyranoside (4), (20S,24S)-16beta-acetoxy-18,24;20,24-diepoxy-9,19-cyclanostane-3beta,25-diol-3-O-beta-D-xylopyranoside (5), 20xi(1),24xi(2)-epoxy-15alpha-acetoxy-9,19-cyclolanostane-3beta,16beta,25-triol-3-O-beta-D-xylopyranoside (6), and 20xi(1),24xi(2)-epoxy-9,19-cyclolanostane-3beta,12alpha,15alpha,16beta,25-pentaol-3-O-beta-D-xylopyranoside (7), respectively.     

Anthelmintic polyfunctional nitrogen-containing terpenoids from marine sponges

The study of the anthelmintic terpenoid components from the Fiji sponge Axinyssa fenestratus (senior synonym of Leucophloeus fenestratus) and two Thailand sponges, Acanthella cavernosa and Topsentia sp., has yielded several new nitrogen-containing sesqui- and diterpenes of known carbon skeletons. Amorphane sesquiterpenes from A. fenestratus included (1R, 6S, 7S, 10S)-10-isothiocyanato-4-amorphene [(+)-1] and new metabolites (1R*, 4S*, 6R*, 7S*)-4-isothiocyanato-9-amorphene [2], 10-isothiocyanato-4,6-amorphadiene [3], and (4S*, 10S*)-10-isothiocyanato-5-amorphen-4-ol [4]. The amorphene (+)-1 of this study may be antipodal to (-)-1 previously isolated from a Hawaiian sponge. A similar relationship may exist at C-1, C-6, C-7 between (+)-2 of this study and (-)-11 isolated from a Palauian sponge. Another known sesquiterpene, axisonitrile 3 [5] was obtained from Topsentia sp. The diterpenes obtained from A. cavernosa included known kalihinols X [6] and Y [8] and new kalihinols J [7] and I [9]. Those terpenoids with potent antiparasite activity include 1, 2, 3-5, and 7-9.     

New stilbene derivatives from Calligonum leucocladum

Two new stilbene derivatives, (E)-resveratrol 3-(6' '-galloyl)-O-beta-D-glucopyranoside (1) and (E)-resveratrol 3-(4' '-acetyl)-O-beta-D-xylopyranoside (2), and five known stilbene derivatives (3-7) were isolated from the dried aerial parts of Calligonum leucocladum. Their structures were established on the basis of spectroscopic evidence. Compound 1 showed antioxidant activity and a restorative effect of the inhibition of oxacillin to oxacillin/methicillin-resistant Staphylococcus aureus.     

Platanionosides A-C, megastigmane diglycosides from the leaves of Alangium platanifolium.

From the leaves of Alangium platanifolium var. platanifolium collected in Fukuoka Prefecture, Japan, three megastigmane diglycosides (1-3) were isolated, along with two known compounds, benzyl alcohol 7-O-beta-D-(6'-O-beta-D-xylopyranosyl)glucopyranoside and Z-hex-3-en-1-ol 1-O-beta-D-glucopyranoside. The structures of the new compounds, named platanionosides A (1), B (2), and C (3) were elucidated by spectroscopic evidence to be 3S,5R,6R,9R, 7E-megastigma-3,9-diol 3,9-di-O-beta-D-glucopyranoside, 3R,9R, 7E-megastigma-5,7-diene-3,9-diol 3,9-di-O-beta-D-glucopyranoside, and 5R,6S,7E-megastigma-3-on-7-en-9-ol 9-O-beta-D-(6'-O-beta-D-xylopyranosyl)glucopyranoside, respectively.     

New nitrogenous eudesmane-type compounds isolated from the Caribbean sponge Axinyssa ambrosia

Fractionation of an acetone-methanol (1:1) extract of the Caribbean marine sponge Axinyssa ambrosia yielded three new sesquiterpenes whose structures were established by spectroscopic methods as (4R*,5R*,7S*,10R*)-eudesm-11-en-4-ylamine hydrochloride (1), axinyssamine hydrochloride, (4R*,5R*,7S*,10R*)-4-isocyanatoeudesm-11-ene (3), and (4R*,5R*,7S*,10R*)-formamidoeudesm-11-ene (4). Compound 1 exhibited significant cytotoxic activity against cancer cells and was also active in a lethality test using polyps of the scleractinian coral Madracis mirabilis.     

New neolignans that inhibit DNA polymerase beta lyase

Bioassay-directed fractionation of a methyl ethyl ketone extract of the roots of Endlicheria aff. resulted in the isolation of four new neolignans (1-4) and eight known compounds, namely, canellin A (5), canellin C (6), 3'-methoxyguianin (7), (7S,8R,1'S,5'S,6'R)-Delta(2',8')-3',6'-dihydroxy-5'-methoxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan (8), armenin-B (9), dillapiole (10), 1-allyl-2,6-dimethoxy-3,4-methylenedioxybenzene (11), and omega-hydroxyisodillapiole (12). The structures of the new compounds (1-4) were established as (7S,8R,1'S,5'S,6'R)-Delta(2',8')-5',6'-dihydroxy-3'-methoxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan, (7S,8R,1'S,5'S,6'R)-Delta(2',8')-3',5',6'-trihydroxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan, 2,4-dimethoxy-5,6-methylenedioxy-1-(2-propenyl)benzene, and 2,6-dimethoxy-3,4-methylenedioxycinnamyl alcohol, respectively, on the basis of spectroscopic interpretation.     

Triterpene glycosides from Cimicifuga racemosa

Eight new triterpene glycosides named cimiracemosides A-H, respectively, and eight known triterpene glycosides were isolated from the rhizome extracts of black cohosh (Cimicifuga racemosa). The new compounds were determined by spectral data to be 21-hydroxycimigenol-3-O-alpha-L-arabinopyranoside (1), 21-hydroxycimigenol-3-O-beta-D-xylopyranoside (2), cimigenol-3-O-alpha-L-arabinopyranoside (3), 12beta-acetoxycimigenol-3-O-alpha-L-arabinopyranoside (4), 24-acetylisodahurinol-3-O-beta-D-xylopyranoside (5), 20(S),22(R), 23(S),24(R)-16beta:23;22:25-diepoxy-12beta-acetoxy-3be ta,23, 24-trihydroxy-9,19-cycloanost-7-ene-3-O-beta-D-xylopyranoside (6), 20(S),22(R),23(S),24(R)-16beta:23;22:25-diepoxy-12beta -acetoxy-3beta, 23,24-trihydroxy-9,19-cycloanost-7-en-3-O-alpha-L-arabinopyrano side (7), and 20(S),22(R),23(S), 24(R)-16beta:23;22:25-diepoxy-12beta-acetoxy-3beta,23, 24-trihydroxy-9,19-cycloanostane-3-O-beta-D-xylopyranoside (8).     

Phenolic compounds from Miconia myriantha inhibiting Candida aspartic proteases.

Assay-guided fractionation of the ethanol extract of the twigs and leaves of Miconia myriantha yielded two new compounds, mattucinol-7-O-[4' ',6' '-O-(S)-hexahydroxydiphenoyl]-beta-D-glucopyranoside (1) and mattucinol-7-O-[4' ',6' '-di-O-galloyl]-beta-D-glucopyranoside (2), along with mattucinol-7-O-beta-D-glucopyranoside (3), ellagic acid (4), 3,3'-di-O-methyl ellagic acid-4-O-beta-D-xylopyranoside, and gallic acid. Complete (1)H and (13)C NMR assignments of compound 1, which possesses a hexahydroxydiphenoyl unit, were achieved using the HMBC technique optimized for small couplings to enhance the four-bond and two-bond H/C correlations. Compounds 1 and 4 showed inhibitory effects against Candida albicans secreted aspartic proteases, with IC(50) of 8.4 and 10.5 microM, respectively.     

紫花地丁全草化学成分研究

目的研究紫花地丁Viola yedoensis全草的化学成分。方法采用硅胶、ODS、Sephadex LH-20凝胶和半制备型高效液相等柱色谱方法进行分离纯化,通过理化性质结合NMR、MS等谱学数据分析鉴定化合物结构。结果从紫花地丁95%乙醇提取物中分离得到21个化合物,分别鉴定为秦皮乙素-6-O-β-D-呋喃芹糖基-(1→2)-β-D-吡喃葡萄糖苷(1)、吲哚-3-甲酸乙酯(2)、脱氢地芰普内酯(3)、滨蒿内酯(4)、蒲公英苦素(5)、水杨苷(6)、丁香苷(7)、4-羟基-4-[3′-(β-D-葡萄糖基)亚丁基]-3,5,5-三甲基-2-环己烯-1-醇(8)、柑橘苷A(9)、(7S,8R)-二氢去氢二松柏醇-9-O-β-D-吡喃葡萄糖苷(10)、山柰素-3-O-α-L-(4-O-乙酰基)鼠李糖基-7-O-α-L-鼠李糖苷(11)、山柰酚-7-O-α-L-鼠李糖苷(12)、山柰酚-3-O-α-L-鼠李糖苷(13)、山柰酚-3-O-α-L-鼠李糖基-7-O-α-L-鼠李糖苷(14)、山柰酚-3-O-β-D-葡萄糖苷(15)、芹菜素(16)、(+)-异地芰普内酯(17)、尿苷(18)、腺苷...     

Beesiosides A-F, six new cycloartane triterpene glycosides from Beesia calthaefolia.

Six new cycloartane triterpene glycosides (1-6), beesiosides A-F, were isolated from whole plants of Beesia calthaefolia, and their structures were elucidated on the basis of extensive NMR experiments and chemical methods. Beesiosides A-F were assigned as (20S,24R)-epoxy-9,19-cyclolanostane-3beta,16beta,18,25-tetraol-3-O-beta-D-xylopyranoside (1), (20S,24R)-epoxy-9,19-cyclolanostane-3beta,12beta,16beta,18,25-pentaol-3-O-beta-D-xylopyranoside (2), (20S,24R)-epoxy-9,19-cyclolanostane-3beta,12alpha,16beta,18,25-pentaol-3-O-beta-D-xylopyranoside (3), (20S,24R)-16beta-acetoxy-20,24-epoxy-9,19-cyclolanostane-3beta,12alpha,18,25-tetraol-3-O-beta-D-xylopyranoside (4), (20S,24R)-epoxy-9,19-cyclolanostane-3beta,15alpha,16beta,18,25-pentaol-3-O-beta-D-xylopyranoside (5), and (20S,24R)-16beta-acetoxy-20,24-epoxy-9,19-cyclolanostane-3beta,12beta,25-triol-3-O-beta-D-xylopyranoside (6), respectively.     

苍耳子中苯丙素类化学成分的研究

目的 研究菊科植物苍耳(Xanthium sibiricum Patrin ex Widder)的干燥成熟带总苞的果实(苍耳子)中苯丙素类化学成分。方法 采用正相硅胶柱色谱、反相十八烷基硅烷键合硅胶(ODS)柱色谱、Sephadex LH-20凝胶柱色谱和半制备高效液相色谱(HPLC)等色谱方法进行分离纯化,并结合高分辨质谱(HR-ESI-MS)、核磁共振(NMR)对分离得到的化合物进行结构鉴定。采用脂多糖(LPS)诱导的巨噬细胞RAW 264.7为筛选模型评价分离得到化合物的抗炎活性。结果 从苍耳子体积分数95%乙醇提取物的乙酸乙酯萃取物中分离并鉴定了24个苯丙素类化合物,分别为c-藜芦酰乙二醇(1)、3,4'-二羟基-3'-甲氧基苯丙酮(2)、阿魏醛(3)、丁香脂素(4)、蛇菰宁(5)、落叶松脂醇(6)、愈创木基甘油(7)、3-hydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(8)、salicifoliol(9)、6-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-2-ol(10)、榕醛(11)、jatrointelignan D(12)、icariol A₂(13)、异落叶松脂素(14)、ehletianol C(15)、(7R,7'R,7”S,7‴S,8S,8'S,8”S,8‴S)-4”,4‴-dihydroxy-3,3',3”,3‴,5,5'-hexamethoxy-7,9';7',9-diepoxy-4,8”;4',8‴-bisoxy-8,8'-dineolignan-7”,7‴,9”,9‴-tetraol(16)、(7R,7'R,7”R,7‴S,8S,8'S,8”S,8‴S)-4”,4‴-dihydroxy-3,3',3”,3‴,5,5'-hexamethoxy-7,9';7',9-diepoxy-4,8”;4',8‴-bisoxy-8,8'-dineolignan-7”,7‴,9”,9‴-tetraol(17)、2-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)-propan-1,3-diol(18)、2,3-bis-(4-hydroxy-3-methoxyphenyl)-3-methoxypropanol(19)、楝叶吴萸素B(20)、threo-guaiacylglycerol-8-vanillin ether(21)、erythro-guaiacylglycerol-8-vanillin ether(22)、黄花菜木脂素B(23)和27-对香豆酰氧基熊果酸(24)。结论 化合物6~24为首次从苍耳中分离得到。对分离得到的24个化合物进行抗炎活性筛选,其中,化合物14、21和23具有抗炎活性,其IC₅₀值分别为(28.14±1.89),(16.78±0.68)和(38.42±2.15)μmol·L^-1。     

Cimiracemosides I-P,new 9,19-cyclolanostane triterpene glycosides from Cimicifuga racemosa

Eight new and 13 known triterpene glycosides, along with the known compounds glyceryl-1-palmitate and daucosterol-6'-linoleate were isolated from the roots/rhizomes of Cimicifuga racemosa. The new compounds, designated as cimiracemosides I-P (1, 3-9), were determined by spectral analysis to be 7-dehydro-23-epi-12,26-dideoxyacteol-3-O-beta-D-xylopyranoside (1), 12-O-acetyl-25-anhydrocimigenol-3-O-alpha-L-arabinopyranoside (3), 12-O-acetyl-25-anhydrocimigenol-3-O-beta-D-xylopyranoside (4), 4',23-O-diacetylshengmanol-3-O-beta-D-xylopyranoside (5), 4',23-O-diacetylshengmanol-3-O-alpha-L-arabinopyranoside (6), 23-epi-acetylacteol-3-O-alpha-L-arabinopyranoside (7), 4'-O-acetyl-26-deoxyactein (8), and 16beta:23;24:25-diepoxy-12beta-O-acetyl-3beta-hydroxy-9,19-cyclolanost-23,26-olide-O- beta-D-xylopyranoside (9).     

毛冬青中木质素苷类化学成分的研究

目的：研究毛冬青的化学成分。方法：溶剂法和色谱法分离化合物,波谱法鉴定其结构。结果：分离得到6个木质素苷类化合物,其结构鉴定为(7S,8R)-dihydrodehydrodiconiferyl alcohol 4-O-β-D-glucopyranoside(1),(-)-olivil-4′-O-β-D-glucopyranoside(2),(7S,8R)dehydrodiconiferyl alcohol 4-O-β-D-glucopyranosid(3),(+)-cyclo-olivil 6-O-β-D-glucopyranoside(4),(+)-medioresinol di-O-β-D-glucopyranoside(5),(+)-pinoresinol-4,4′-O-bisglucopyranoside(6)。结论：以上化合物均为首次从该属植物中分离得到。     

兴安黄芪化学成分研究

目的:研究兴安黄芪的化学成分。方法:用硅胶柱色谱、重结晶及半制备HPLC进行分离纯化,根据理化性质和光谱数据进行结构鉴定。结果:得到6个单体化合物,分别为7,2′-二羟基-3,′4′-二甲氧基异黄烷(1),2′-羟基-3,′4′-二甲氧基异黄烷-7-O--βD-葡萄糖苷(2),8,2′-二羟基-7,4′-二甲氧基异黄烷(3),7-羟基-4′-甲氧基异黄酮(4),7,3′-二羟基-4′-甲氧基异黄酮(5),9,10-二甲氧基紫檀烷-3-O--βD-葡萄糖苷(6)。结论:这些化合物均系首次从该植物中得到。     

Bromophenols from the red alga Rhodomela confervoides

Six new bromophenols, 3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)pyrocatechol (1), 2,2',3-tribromo-3',4,4',5-tetrahydroxy-6'-hydroxymethyldiphenylmethane (2), 2,2',3-tribromo-3',4,4',5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane (3), (+/-)-2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde (4), (+/-)-2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde dimethyl acetal (5), and 3-bromo-4,5-dihydroxybenzoic acid methyl ester (6), together with eight known bromophenols, 3-bromo-4,5-dihydroxybenzaldehyde (7), 2,3-dibromo-4,5-dihydroxybenzyl alcohol (lanosol, 8), 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (9), 2,3-dibromo-4,5-dihydroxybenzyl ethyl ether (10), 2,3-dibromo-4,5-dihydroxybenzylaldehyde (11), bis(2,3-dibromo-4,5-dihydroxybenzyl) ether (12), 3-bromo-4-(2,3-dibromo-4,5-dihydroxybenzyl)-5-methoxymethylpyrocatechol (13), and 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenyl methane (14), were isolated from the red alga Rhodomela confervoides. Their structures were elucidated by chemical and spectroscopic methods including IR, HRFABMS, and 1D and 2D NMR techniques.     

Phenylvaleric acid and flavonoid glycosides from Polygonum salicifolium.

(3R)-O-beta-D-Glucopyranosyloxy-5-phenylvaleric acid (1), (3R)-O-beta-D-glucopyranosyloxy-5-phenylvaleric acid n-butyl ester (2), and a new dihydrochalcone diglycoside 4'-O-[beta-D-glucopyranosyl-(1-->6)-glucopyranosyl]oxy-2'-hydroxy-3', 6'-dimethoxydihydrochalcone (3), together with six known flavonoid glycosides [kaempferol-3-O-beta-D-glucopyranoside (= astragalin) (4), kaempferol-3-O-beta-D-galactopyranoside (5), quercetin-3-O-beta-D-glucopyranoside (= isoquercitrin) (6), quercetin-3-O-beta-D-galactopyranoside (= hyperoside) (7), quercetin-3-O-(2'-O-galloyl)-beta-D-glucopyranoside (8), and quercetin-3-O-beta-D-glucuronopyranoside (9)] were isolated from the aerial parts of Polygonum salicifolium. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, ESI-MS, 1D- and 2D-NMR), chemical (methylation, enzymatic hydrolysis, partial synthesis), and chromatographic methods (HPLC, Chiralcel OD). The flavonoid glycosides (4-9) demonstrated scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC autographic assays.     

Isothiocyanate sesquiterpenes from a sponge of the genus axinyssa

The chemical study of a sponge of the genus Axinyssa collected in the Gulf of California has led to the isolation of the new bicyclic sesquiterpenes axinisothiocyanates A-L ( 1- 12) together with the known compounds (1 R,6 S,7 S,10 S)-10-isothiocyanato-4-amorphene ( 13), (4 R*,5 R*,7 S*,10 R*)-4-isocyanoeudesm-11-ene, (-)-epipolasin A, and (+)-aristolone. The structures of the new metabolites have been established by spectroscopic techniques, including the analysis of pyridine-induced 1H NMR chemical shifts. The cytotoxic activity has been tested against three human tumor cell lines.