Madhucosides A and B, protobassic acid glycosides from Madhuca indica with inhibitory activity on free radical release from phagocytes

The structures of madhucosides A (1) and B (2), isolated from the bark of Madhuca indica, were established as 3-O-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranosyl-28-O-[beta-D-xylopyranosyl(1-->2)-[alpha-L-rhamnopyranosyl(1-->4)]-beta-D-glucopyranosyl(1--> 3)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl]protobassic acid and 3-O-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranosyl-28-O-[beta-D-xylopyranosyl(1-->2)-[alpha-L-rhamnopyranosyl(1-->4)]-beta-D-glucopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl]protobassic acid, respectively. These two compounds showed significant inhibitory effects on both superoxide release from polymorphonuclear cells in a NBT reduction assay and hypochlorous acid generation from neutrophils assessed in a luminol-enhanced chemiluminescence assay.     

Four new flavonol glycosides from the leaves of Astragalus caprinus

Four new flavonol 3-O-glycosides were isolated from the leaves of Astragalus caprinus. Their structures were elucidated by spectroscopic methods as rhamnocitrin-3-O-[3-hydroxy-3-methylglutaroyl(1-->6)][beta-D-apiofuranosyl(1-->2)]-beta-D-galactopyranoside (1), rhamnetin-3-O-[3-hydroxy-3-methylglutaroyl(1-->6)][beta-D-apiofuranosyl(1-->2)]-beta-D-galactopyranoside (2), kaempferol-3-O-[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)]-beta-D-galactopyranoside (3), and quercetin-3-O-[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][beta-D-apiofuranosyl(1-->2)]-beta-D-galactopyranoside (4).     

Two major saponins from seeds of Barringtonia asiatica: putative antifeedants toward Epilachna sp. larvae

Two major saponins have been isolated from a methanol extract of the seeds of Barringtonia asiatica, and their structures elucidated (mainly by two-dimensional NMR spectroscopy) as 3-O-[[beta-D-galactopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->2)]-beta-D-glucuronopyranosyloxy]-22-O-(2-methylbutyroyloxy)-15,16,28-trihydroxy-(3beta,15alpha,16alpha,22alpha)-olean-12-ene (3) and 3-O-[[beta-D-galactopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->2)]-beta-D-glucuronopyranosyloxy]-22-O-[2(E)-methyl-2-butenyloyloxy]-15,16,28-trihydroxy-(3beta,15alpha,16alpha,22alpha)-olean-12-ene (4). The antifeedant properties of 3 and 4 toward Epilachna larvae are discussed.     

Triterpene saponins from Eryngium campestre

Five new triterpene saponins, 3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucuronopyranosyl-22-O-beta,beta-dimethylacryloyl-A1-barrigenol (1), 3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucuronopyranosyl-22-O-angeloyl-R1-barrigenol (2), 3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucuronopyranosyl-21-O-acetyl-22-O-angeloyl-R1-barrigenol (3), 3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucuronopyranosyl-21-O-acetyl-22-O-beta,beta-dimethylacryloyl-R1-barrigenol (4), and 3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucuronopyranosyl-22-O-angeloyl-28-O-acetyl-R1-barrigenol (5), were isolated from the roots of Eryngium campestre. Their structures were established mainly by 2D NMR techniques and mass spectrometry. Compounds 1-4 and 3-O-beta-d-glucopyranosyl-(1-->2)-[alpha-l-rhamnopyranosyl-(1-->4)]-beta-d-glucuronopyranosyl-22-O-beta,beta-dimethylacryloyl-A1-barrigenol, previously isolated from the same plant, showed a weak cytotoxicity when tested against HCT 116 and HT 29 human colon cancer cells.     

日本七叶树化学成分的研究△Ⅱ．七叶树皂苷IVc和异七叶树皂苷Ia、Ib的分离和鉴定

从日本七叶树Aesculus turbinata B1．种子的90％乙醇提取物中分得3个二萜皂化合物,经光谱学分析鉴定了它们的结构分别为：七叶树皂苷IVc：22α-O-巴豆酰基-28-O-乙酰基原七叶树皂苷配基-3β-O-[β-D-吡喃葡萄糖基(1→2)][β-D-吡喃葡萄糖基(1→4)]-β-D-吡喃葡萄糖醛酸(I)、异七叶树皂苷Ia：21β-O-巴豆酰基-28-O-乙酰基原七叶树皂苷配基-3β-O-[β-D-吡喃葡萄糖基(1→2)[β-D-吡喃葡萄糖基(1→4)]-β-D-吡喃葡萄糖醛酸(Ⅳ)和异七叶树皂苷Ib：21β-O-当归酰基-28-O-乙酰基原七叶树皂苷配基-3β-O-[β-D-吡喃葡萄糖基(1→2)[β-D-吡喃葡萄糖基(1→4)]-β-D-吡喃葡萄糖醛酸(V),均为首次从日本七叶树种子中分得。七叶树皂苷Ia、Ib、IVc和异七叶树皂苷Ia、Ib在100 μmol／L浓度的体外试验中对HIV-1蛋白酶活性具有一定的抑制作用。     

Two new glycosides from Astragalus caprinus

A new glycoside of flavonol (1) and a new glycoside of a cycloartane-type triterpene (2) were isolated from the leaves and the roots of Astragalus caprinus, respectively. Their structures were elucidated in turn by spectroscopic data interpretation as 3-O-[[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][beta-D-apiofuranosyl(1-->2)]]-beta-D-galactopyranosyl kaempferol (1) and 3-O-(beta-D-xylopyranosyl)-24-O-(beta-D-glucopyranosyl)-20,25-epoxycycloartane-3beta,6alpha,16beta,24alpha-tetrol (2).     

Triterpenoid saponins from the roots of Pulsatilla koreana

Six new saponins, five lupanes (1-5) and one oleanane (6), along with 11 known saponins, were isolated from the roots of Pulsatilla koreana. The structures of the new saponins were found to be 23-hydroxy-3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (1), 23-hydroxy-3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (2), 3beta-[(O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (3), 3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (4), 23-hydroxy-3beta-[(O-beta-D-glucopyranosyl-(1-->4)-alpha-L-arabinopyranosyl)oxy]lup-20(29)-en-28-oic acid (5), and hederagenin 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside (6). Their structures were determined on the basis of 1D and 2D NMR ((13)C NMR, (1)H NMR, (1)H-(1)H COSY, HMQC, and HMBC) methods, FABMS, and hydrolysis. All isolated compounds were evaluated for their cytotoxic activity against A-549 human lung carcinoma cells.     

Antifungal activities and action mechanisms of compounds from Tribulus terrestris L

Antifungal activity of natural products is being studied widely. Saponins are known to be antifungal and antibacterial. We used bioassay-guided fractionation to have isolated eight steroid saponins from Tribulus terrestris L., which were identified as hecogenin-3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-8), tigogenin-3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-9), hecogenin-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-10), hecogenin-3-O-beta-D-xylopyranosyl (1-->3)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-11), tigogenin-3-O-beta-D-xylopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-galactopyranoside (TTS-12), 3-O-[beta-D-xylopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-galactopyranosyl]-26-O-beta-D-glucopyranosyl-22-methoxy-(3beta,5alpha,25R)-furostan-3,26-diol (TTS-13), hecogenin-3-O-beta-D-glucopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-14), tigogenin-3-O-beta-D-glucopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-15). The in vitro antifungal activities of the eight saponins against five yeasts, Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis and Cryptococcus neoformans were studied using microbroth dilution assay. In vivo activity of TTS-12 in a Candida albicans vaginal infection model was studied in particular. The results showed that TTS-12 and TTS-15 were very effective against several pathogenic candidal species and Cryptococcus neoformans in vitro. It is noteworthy that TTS-12 and TTS-15 were very active against Candida albicans (MIC(80) = 10 and 2.3 microg/mL) and Cryptococcus neoformans (MIC(80) = 1.7 and 6.7 microg/mL). Phase contrast microscopy showed that TTS-12 inhibited hyphal formation, an important virulence factor of Candida albicans, and transmission electron microscopy showed that TTS-12 destroyed the cell membrane of Candida albicans. In conclusion, TTS-12 has significant in vitro and in vivo antifungal activity, weakening the virulence of Candida albicans and killing fungi through destroying the cell membrane.     

Oleanane saponins in "kancolla", a sweet variety of Chenopodium quinoa

Seven triterpenoid saponins were isolated from the seeds of "kancolla", a sweet variety of Chenopodium quinoa. Their structures were phytolaccagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside, oleanolic acid 3-O-[beta-D-glucopyranosyl-(1'-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside, hederagenin 3-O-[beta-D-glucopyranosyl-(1'-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside, phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1'-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside, oleanolic acid 3-O-[beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside, oleanolic acid 3-O-[alpha-L-arabinopyranosyl-(1'-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside, and the new compound serjanic acid 3-O-[beta-D-glucopyranosyl-(1'-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (1). The structure of 1 was characterized on the basis of spectroscopic and chemical evidence.     

Five new triterpene saponins from Pulsatilla patens var. multifida

Five new oleanane-type glycosides (1-5), along with two known triterpene saponins, were isolated from the roots of Pulsatilla patens var. multifida (Ranunculaceae). The structures of the new triterpene saponins were elucidated as 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-galactopyranosyl hederagenin 28-O-beta-D-glucopyranosyl ester (1), hederagenin 3-O-[beta-D-glucopyranosyl(1-->2)][beta-D-glucopyranosyl(1-->6)]-beta -D-galactopyranoside (2), 3-O-beta-D-glucopyranosyl bayogenin 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta -D-glucopyranosyl ester (3), 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-galactopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta -D-glucopyranosyl ester (4), and 3-O-[beta-D-glucopyranosyl(1-->2)][beta-D-glucopyranosyl(1-->6)]-beta -D-galactopyranosyl hederagenin 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta -D-glucopyranosyl ester (5). Structure elucidation was accomplished by 1D and 2D NMR (HMQC, HMBC, and ROESY) methods, FABMS, and hydrolysis.     

Silenosides A-C, triterpenoid saponins from Silene vulgaris.

Three new triterpenoid saponins named silenosides A-C (1-3) were obtained from the roots of Silene vulgaris. Their structures were elucidated by spectral and chemical methods as beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl-3beta- hydrox y-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl(1-->4)-alpha-L- rhamnopyranosyl(1-->2)-beta-D-fucopyranoside; 3-O-beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl-3beta , 16alpha-dihydroxy-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->4)-[beta-D-glucopyranosyl(1-->2)]-alpha -L-rhamnopyranosyl(1-->2)-beta-D-fucopyranoside; and 3-O-alpha-L-arabinopyranosyl(1-->3)-[beta-D-galactopyranosyl(1-->2 )]- beta-D-glucuronopyranosyl-3beta, 16alpha-dihydroxy-23-oxoolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->4)-[beta-D-glucopyranosyl(1-->2)]-alpha -L-rhamnopyranosyl(1-->2)-beta-D-fucopyranoside, respectively.     

A new triterpenoidal saponin from Acacia auriculiformis.

A new triterpenoidal saponin has been isolated from an aqueous EtOH extract of the legumes of Acacia auriculiformis and characterized as 3-O-([beta-D-xylopyranosyl(1----3)-beta-D-xylopyranosyl(1----4)-alpha-L- rhamnopyranosyl(1----2)]-[alpha-L-rhamnopyranosyl(1----4)]-beta-D- glucopyranosyl)-3,16,21-trihydroxyolean-12-en-28-oic acid [1] by chemical studies and spectral data.     

Kinmoonosides A-C, three new cytotoxic saponins from the fruits of Acacia concinna, a medicinal plant collected in myanmar

Three genuine saponins, named kinmoonosides A-C (1-3), have been isolated, together with a new monoterpenoid (4), from a methanolic extract of the fruits of Acacia concinna. The structures of kinmoonosides A-C were elucidated on the basis of spectral analysis as 3-O-?alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl?-21-O-?(6R, 2E)-2-hydroxymethyl-6-methyl-6-O-[4-O-(2'E)-6'-hydroxyl-2'-hydroxymet hyl-6'-methyl-2',7'-octadienoyl-beta-D-quinovopyranosyl]-2, 7-octadienoyl?acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (1); 3-O-?alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl?-21-O-?(6S, 2E)-2-hydroxymethyl-6-methyl-6-O-[4-O-(2'E)-6'-hydroxyl-2'-hydroxymet hyl-6'-methyl-2',7'-octadienoyl-beta-D-quinobopyranosyl]-2, 7-octadienoyl?acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (2); and 3-O-?alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl?-21-O-[(2E)-6-hydroxyl-2-hydroxymethyl-6-methyl- 2,7-octadienoyl]acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (3), respectively. The new monoterpenoid 4 was determined as 4-O-[(2E)-6-hydroxyl-2-hydroxymethyl-6-methyl-2, 7-octadienoyl]-D-quinovopyranose. Compounds 1-3 showed significant cytotoxicity against human HT-1080 fibrosarcoma cells.     

Four new triterpenoid saponins from Conyza blinii

Three new bisdesmosidic saponins named conyzasaponins A, B, and C (1-3) and one new monodesmosidic saponin, conyzasaponin G (4), were isolated from the aerial parts of Conyza blinii. Their structures were elucidated on the basis of extensive NMR (DEPT, DQF-COSY, HOHAHA, HMQC, HMBC, and NOESY) and MS studies. Compounds 1-3 share a common prosapogenin, bayogenin 3-O-beta-D-xylopyranosyl-(1-->3)-beta-D-glucopyranoside, which is identical with conyzasaponin G (4), and differ in the structures of the ester-linked sugar moieties at C-28. Conyzasaponin A (1) is the 28-O-beta-D-apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester, conyzasaponin B (2), the 28-O-beta-D-apiofurano- syl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[alpha-L-arabinopyranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester, and conyzasaponin C (3), the 28-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester of the prosapogenin, respectively.     

A new saponin from Deeringia amaranthoides

A new triterpenoid saponin, 3-O-[alpha-L-rhamnopyranosyl (1----3)-beta-D-glucuronopyranosyl]-28-O-[beta-D-xylopyranosyl (1----2)-beta-D-glucopyranosyl]-3 beta-hydroxyolean-12-en-28-oate [3] has been isolated together with two known saponins, 3-O-[alpha-L-rhamnopyranosyl (1----3)-beta-D-glucuronopyranosyl]-3 beta- hydroxyolean-12-en-28-oic acid [1] and 3-O-[alpha-L-rhamnopyranosyl (1----3)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-3 beta- hydroxyolean-12-en-oate [2], from the fruits of Deeringia amaranthoides.     

New lignan glycosides with potent antiinflammatory effect, isolated from Justicia ciliata

Two new lignan glycosides, 4-O-[alpha-L-arabinopyranosyl-(1' "-->2' ')-beta-D-xylopyranosyl-(1' " '-->5' ')-beta-D-apiofuranosyl]diphyllin (1), named ciliatoside A (1), and 4-O-?[beta-D-apiofuranosyl-(1' " "-->3' ")-alpha-L-arabinopyranosyl-(1' "-->2' ')][beta-D-xylopyranosyl-(1' " '-->5' ')]-beta-D-apiofuranosyl?diphyllin (2), named ciliatoside B (2), were isolated from the whole plant of Justicia ciliata. The structures of 1 and 2 were determined by spectral and chemical methods. Compounds 1 and 2 strongly inhibited the accumulation of NO(2)(-) in lipopolysaccharide-stimulated RAW 264.7 cells in a concentration-dependent manner with IC(50) values of 27.1 +/- 1.6 and 29.4 +/- 1.4 microM, respectively.     

Acylated triterpenoid saponins from Schima noronhae and their cell growth inhibitory activity

Two new acylated triterpenoid saponins were isolated from the branches of Schima noronhae by bioassay-guided purification. Their chemical structures were established on the basis of spectroscopic analysis and chemical means as 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl 22-O-angeloyl-A1-barrigenol (1) and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl 22-O-angeloylerythrodiol (2). Compounds 1 and 2 showed cell growth inhibitory activity against both HeLa and DLD1 cells at a concentration of less than 10 microM.     

Yemuoside I, a new nortriterpenoid glycoside from Stauntonia chinensis.

A new nortriterpenoid glycoside, named yemuoside [I] was isolated from Stauntonia chinensis. On the basis of chemical and spectral evidence, it structure was determined as 3-O-[alpha-L-arabinopyranosyl-(1----3)-alpha-L-rhamnopyranosyl-(1- ---2)-alpha-L-arabinopyranosyl]-30-noroleana-12,20(29)-di en-28-oic acid 28-O-[beta-D-glucopyranosyl-(1----6)-beta-D-glucopyranosyl] ester.     

Trypanocidal withanolides and withanolide glycosides from Dunalia brachyacantha.

Two new withanolide glycosides, (20R,22R)-O-(3)-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl-1 alpha,12 beta-diacetoxy-20-hydroxywitha-5,24-dienolide (3) and (20R,22R)-O-(3)-beta-D-xylopyranosyl(1-->3)-[beta-D-xylopyranosyl(1-->4)]-beta-D-glucopyranosyl-1 alpha-acetoxy-12 beta,20-dihydroxywitha-5,24-dienolide (4), were isolated from the leaves and root of Dunalia brachyacantha. Their aglycones, (20R,22R)-1 alpha,12 beta-diacetoxy-3 beta,20-dihydroxywitha-5,24-dienolide (or 1 alpha,12 beta-diacetyldunawithagenine) and (20R,22R)-1 alpha-acetoxy-3 beta,12 beta,20-trihydroxywitha-5,24-dienolide (or 1 alpha-acetyl-12 beta-hydroxydunawithagenine), are novel. The known 18-acetoxywithanolide D (1) and 18-acetoxy-5,6-deoxy-5-withenolide D (2) were also isolated from the leaves. These last two compounds were shown to be responsible for the trypanocidal, leishmanicidal, and bactericidal activities manifested by the crude ethanolic extract. The structures were deduced from spectroscopic data and on the basis of chemical evidence.     

Bioactive constituents from Boswellia papyrifera

Phytochemical investigation of the stem bark extract of Boswellia papyrifera afforded two new stilbene glycosides, trans-4',5-dihydroxy-3-methoxystilbene-5-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranoside (1), trans-4',5-dihydroxy-3-methoxystilbene-5-O-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranoside (2), and a new triterpene, 3alpha-acetoxy-27-hydroxylup-20(29)-en-24-oic acid (3), along with five known compounds, 11-keto-beta-boswellic acid (4), beta-elemonic acid (7), 3alpha-acetoxy-11-keto-beta-boswellic acid (8), beta-boswellic acid (9), and beta-sitosterol (10). The stilbene glycosides exhibited significant inhibition of phosphodiesterase I and xanthine oxidase. The triterpenes (3-9) exhibited prolyl endopeptidase inhibitory activities.