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).     

Neuroprotective constituents from Hedyotis diffusa

In a bioassay-guided search for neuroprotective compounds from medicinal plants, a MeOH extract of whole plants of Hedoytis diffusa yielded five flavonol glycosides, kaempferol 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (1), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (2), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-glucopyranoside (3), kaempferol 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (4), and quercetin 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (5), and four O-acylated iridoid glycosides (6-9). Compounds 1 and 2 are previously unreported natural products, and all nine compounds exhibited significant neuroprotective activity in primary cultures of rat cortical cells damaged by L-glutamate.     

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.     

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.     

Antifungal jujubogenin saponins from Colubrina retusa.

Antifungal assay-guided isolation of the 95% ethanol extract of the stems of Colubrina retusa yielded jujubogenin 3-O-alpha-L-arabinofuranosyl(1-->2)-[beta-D-glucopyranosyl (1-->3)]-alpha-L-arabinopyranoside (1), which showed modest growth-inhibitory effects against Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus (MICs, 50 microg/mL). In addition, two new minor saponins, jujubogenin 3-O-alpha-L-arabinofuranosyl(1-->2)-[2-O-(trans, cis)p-coumaroyl-beta-D-glucopyranosyl(1-->3)]-alpha-L-arabinopy ranosi de (2), and jujubogenin 3-O-(5-O-malonyl)-alpha-L-arabinofuranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]-alpha-L-arabinopyranoside (3), were obtained. Saponin 2 was marginally active against only C. neoformans, with a MIC of 50 microg/mL, while 3 was inactive. NMR spectroscopy was used extensively for the structure determination of these compounds. The previously reported ambiguity of the NMR assignments of jujubogenin saponins for carbons -26 to -29 was clarified by a comprehensive analysis of the NMR spectra of 1.     

素馨花三萜皂苷类化学成分研究

目的:研究木犀科茉莉属植物素馨花干燥花蕾的化学成分。方法:通过硅胶柱色谱、Sephadex LH-20柱色谱和重结晶等方法进行分离纯化,根据化合物的理化性质和波谱数据鉴定结构。结果:从素馨花干燥花蕾70%乙醇提取物中分离得到6个三萜皂苷类化合物,分别鉴定为3-O-α-L-吡喃鼠李糖基(1→2)-β-D-吡喃木糖基常春藤皂苷元-28-O-β-D-吡喃半乳糖基(1→6)-β-D-吡喃半乳糖酯苷(1)、常春藤皂苷元3-O-β-D-吡喃葡萄糖基(1→3)-α-L-吡喃阿拉伯糖苷(2)、2α,3β,23-trihydroxyolean-12-en-28-oic-O-β-D-glucopyranosyl ester(3)、常春藤皂昔元-3-O-β-D-吡喃木糖基(1→3)-α-L-吡喃鼠李糖基(1→2)-α-L-吡喃阿拉伯糖苷(4)、2α,3β,23-trihydroxyolean-12-en-28-oic-O-α-L-rhamnopyranosyl(1→4)-O-β-D-glucopyranosyl(1→6)-β-D-glucopyranosyl ester(5)、常春藤皂苷元-3-O-α-L-吡喃鼠李糖基(1→)2-α-L-吡喃阿拉伯糖苷(6)。结论:化合物1为新化合物,化合物26为首次从茉莉属植物中分离得到。     

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.     

Flavonoid glycosides from Rhazya orientalis

Six new flavonoid glycosides, quercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl(1-->2)]-(4-O-trans-p-coumaroyl)-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside (1), quercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl(1-->2)]-(3-O-trans-p-coumaroyl)-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside (2), isorhamnetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl(1-->2)]-(4-O-trans-p-coumaroyl)-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside (3), isorhamnetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl(1-->2)]-(3-O-trans-p-coumaroyl)-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside (4), isorhamnetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl(1-->2)]-(4-O-cis-p-coumaroyl)-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside (5), and isorhamnetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-[alpha-L-rhamnopyranosyl(1-->2)]-(4-O-trans-feruloyl)-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside (6), were isolated from the dried aerial parts of Rhazya orientalis. The structures of 1-6 were determined by spectroscopic and chemical means.     

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.     

Antifungal substances against pathogenic fungi, talaroconvolutins, from talaromyces convolutus

The dichloromethane extract of Talaromyces convolutus cultivated on barley exhibited antifungal activity against Candida albicans. In the course of a search for the active compounds, four new tetramic acid derivatives, talaroconvolutins A (1), B (2), C (3), and D (4), were isolated along with ZG-1494alpha (5), and mitorubrin derivatives. The structures of talaroconvolutins A-D (1-4) were established on the basis of spectroscopic and chemical investigations and chemical correlations. The antifungal activity of the talaroconvolutins against the pathogenic fungi Aspergillus fumigates, Aspergillus niger, C. albicans, and Cryptococcus neoformans was determined.     

合欢皂甙J6的结构鉴定

目的 :从合欢皮中分离皂甙。方法 :用色谱法分离 ,波谱法鉴定其结构。结果和结论 :从合欢皮的 95%乙醇提取物中分得 1个三糖链八糖皂甙 ,结构为 3-O [β-D 吡喃木糖基 ( 1→ 2 )-α-L 吡喃阿拉伯糖基 ( 1→ 6)-β-D 2 去氧 2 乙酰胺基 吡喃葡萄糖基 ] 21O {6S2 反式2羟甲基6甲基6-o[4-O ( 6S-2 反式-2 羟甲基 6-甲基 6-羟基 2 ,7 辛二烯酰基 ) β D 吡喃鸡纳糖基 ] 2 ,7 辛二烯酰基 } 金合欢酸-28-O-β-D 吡喃葡萄糖基 (1→ 3)[α- L 呋喃阿拉伯糖基 (1→ 4) ] α L 吡喃鼠李糖基 (1→ 2)-β-D 吡喃葡萄糖酯 ,为新化合物 ,命名为合欢皂甙J6 。     

Floratheasaponins A-C, acylated oleanane-type triterpene oligoglycosides with anti-hyperlipidemic activities from flowers of the tea plant (Camellia sinensis)

The methanolic extract and its n-butanol-soluble fraction from the flowers of the tea plant (Camellia sinensis) were found to suppress serum triglyceride elevation in olive oil-treated mice. From the n-butanol-soluble fraction, three new acylated oleanane-type triterpene oligoglycosides, floratheasaponins A-C (1-3), were isolated together with several flavonol glycosides and catechins. The structures of 1-3 were elucidated on the basis of chemical and physicochemical evidence as 21-O-angeloyl-22-O-acetyltheasapogenol B 3-O-[beta-D-galactopyranosyl(1-->2)][beta-D-xylopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, 21,22-di-O-angeloyl-R1-barrigenol 3-O-[beta-D-galactopyranosyl(1-->2)][beta-D-xylopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, and 21-O-angeloyl-22-O-2-methylbutyryl-R1-barrigenol 3-O-[beta-D-galactopyranosyl(1-->2)][beta-D-xylopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->3)]-beta-D-glucopyranosiduronic acid, respectively. Floratheasaponins (1-3) showed inhibitory effects on serum triglyceride elevation, with their activities being more potent than those of theasaponins E1 (4) and E2 (5) obtained previously from the seeds of C. sinensis.     

Steroidal saponins from the rhizomes of Polygonatum sibiricum

Four new steroidal saponins, named neosibiricosides A-D (1-4), were isolated from the rhizomes of Polygonatum sibiricum, along with two known spirostanol glycosides. The structures of the new glycosides were elucidated by spectroscopic methods and acid hydrolysis as (23S,24R,25R)-1-O-acetylspirost-5-ene-1beta,3beta,23,24-tetrol 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-beta-D-fucopyranoside (1), (25S)-1-O-acetylspirost-5-ene-1beta,3beta-diol 3-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside (2), (25S)-spirost-5-en-3beta-ol 3-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-2-O-acetyl-beta-D-galactopyranoside (3), and (25R,S)-spirost-5-en-3beta-ol 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside (4). The cytotoxic activity of the isolated compounds was evaluated with human MCF-7 breast cancer cells.     

An acetylated bidesmosidic saponin from Schefflera octophylla.

A new acetylated bidesmosidic triterpenoid saponin has been isolated from the leaves of Schefflera octophylla and structurally elucidated as 3-epi-betulinic acid 3-O-beta-D-6'-acetylglucopyranoside 28-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)]-bet a-D-0-glucopyranoside [1].     

Four new triterpenoidal saponins acylated with one monoterpenic acid from Gleditsia sinensis.

Four new oleanane-type triterpenoidal glycosides, named gleditsiosides A-D (1-4), were isolated from the anomalous fruits of Gleditsia sinensis. Using modern NMR techniques, including DQF-COSY, HETCOR, HOHAHA, HMBC, and ROESY experiments and MS analysis as well as chemical methods, their structures were determined as 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl oleanolic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha- L-rhamnopyranosyl-(1-->2)-[(6S,2E)-6-hydroxy-2,6-dimethyl-2, 7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (1); 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl oleanolic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha- L-rhamnopyranosyl-(1-->2)-[(2E)-2-hydroxylmethyl-6-hydroxy-6-methy l-2 ,7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (2); 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl echinocystic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta- D-galactopyranosyl-(1-->2)]-alpha-L-rhamnopyranosyl-(1-->2)-[(2E)-2-h ydroxylmethyl-6-hydroxy-6-methyl-2, 7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (3); and 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl echinocystic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta- D-galactopyranosyl-(1-->2)]-alpha-L-rhamnopyranosyl-(1-->2)-[(6S, 2E)-6-hydroxy-2,6-dimethyl-2, 7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (4).     

New steroidal glycosides from the fruits of Tribulus terrestris

Three new steroidal saponins (1-3) were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic methods (IR, HRESIMS, 1D- and 2D-NMR) as 26-O-beta-D-glucopyranosyl-(25S)-5beta-furost-20(22)-en-3bet a, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl- (1-->4)]-beta-D-glucopyranoside (1), 26-O-beta-D-glucopyranosyl-(25S)-5beta-furost-20(22)-en-3bet a, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1 -->4)]-beta-D-galactopyranoside (2), and 25(S)-5beta-spirostan-3beta-ol-3-O-alpha-L-rhamnopyranosyl-( 1-->2)-[b eta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (3). Compound 3 showed cytotoxicity against a human malignant melanoma cell line (SK-MEL).     

Antifungal activity of anthraquinone derivatives from Rheum emodi

Rhein, physcion, aloe-emodin and chrysophanol isolated from Rheum emodi rhizomes exhibited antifungal activity against Candida albicans, Cryptococcus neoformans, Trichophyton mentagrophytes and Aspergillus fumigatus (MIC 25-250 microg/ml).     

Antifungal activity of some Tanzanian plants used traditionally for the treatment of fungal infections

Using the ethnobotanical approach, some Tanzanian plants reported to be used by traditional healers for the treatment of oral candidiasis and fungal infections of the skin were collected and screened for their antifungal activity against Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida krusei and Cryptococcus neoformans. A total of 65 crude methanol extracts belonging to 56 plant species and 38 families were screened using the broth microdilution method, according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI) (formerly, National Committee for Clinical and Laboratory Standards) [National Committee for Clinical Laboratory Standards, 2002. Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts. Approved Standard-2nd Edition M27-A2, National Committee for Clinical Laboratory Standards, Wayne, PA, USA]. Among the tested plant species, 45% (25 species) showed antifungal activity against one or more of the test fungi. The most susceptible yeasts were Cryptococcus neoformans, followed by Candida krusei, Candida tropicalis, and Candida parapsilosis. The least susceptible were Candida albicans and Candida glabrata. Strong antifungal activity was exhibited by extracts of Clausena anisata Oliv., Sclerocariya birrea Sond, Turraea holstii Gurk, Sterculia africana (Lour) Fiori, Acacia robusta subsp. Usambarensis (Taub) Brenan, Cyphosterma hildebrandti (Gilg), Desc, Elaeodendron buchannanii (Lows), Acacia nilotica (L.) Wild ex Del, Jatropha multifida L., and Pteridium aquilinum (L.) Kuhn.     

Fatty acid synthase inhibitors from plants: isolation,structure elucidation,and SAR studies

Fatty acid synthase (FAS) has been identified as a potential antifungal target. FAS prepared from Saccharomyces cerevisiae was employed for bioactivity-guided fractionation of Chlorophora tinctoria,Paspalum conjugatum, Symphonia globulifera, Buchenavia parviflora, and Miconia pilgeriana. Thirteen compounds (1-13), including three new natural products (1, 4, 12), were isolated and their structures identified by spectroscopic interpretation. They represented five chemotypes, namely, isoflavones, flavones, biflavonoids, hydrolyzable tannin-related derivatives, and triterpenoids. 3'-Formylgenistein (1) and ellagic acid 4-O-alpha-l-rhamnopyranoside (9) were the most potent compounds against FAS, with IC(50) values of 2.3 and 7.5 microg/mL, respectively. Furthermore, 43 (14-56) analogues of the five chemotypes from our natural product repository and commercial sources were tested for their FAS inhibitory activity. Structure-activity relationships for some chemotypes were investigated. All these compounds were further evaluated for antifungal activity against Candida albicans and Cryptococcus neoformans. Although there were several antifungal compounds in the set, correlation between the FAS inhibitory activity and antifungal activity could not be defined.