Four new dammarane saponins from Zizyphus lotus

Five dammarane-type saponins were isolated by means of centrifugal partition chromatography from the leaves of Zizyphus lotus. Their structures were elucidated using a combination of 1D and 2D 1H and 13C NMR spectra and mass spectroscopy. One of these glycosides is the known jujuboside B (5). Three are new jujubogenin glycosides, identified as 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyljujubogenin-20-O-(2,3,4-O-triacetyl)-alpha-L-rhamnopyranoside (1), 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyljujubogenin-20-O-alpha-L-rhamnopyranoside (2), and 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[(4-sulfo)-beta-D-glucopyranosyl-(1-->3)]-alpha-L-arabinopyranosyljujubogenin (3). The last is a new sulfated derivative of jujubasaponine IV, identified as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[(4-sulfo)-beta-D-glucopyranosyl-(1-->3)]-beta-D-galactopyranosyl-(20R,22R)-16beta,22:16alpha,30-diepoxydammar-24-ene-3beta,20-diol (4).     

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.     

Cytotoxic withaphysalins from the leaves of Acnistus arborescens

Three withaphysalins, rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-1,18-dioxowitha-2,24-dienolide(withaphysalin M) (1), rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-18-ethoxy-1-oxowitha-2,24-dienolide (withaphysalin F ethyl ether, withaphysalin O) (2), and rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-1,18-dioxowitha-24-enolide (withaphysalin N) (3), were isolated from the leaves of Acnistus arborescens. The structures were deduced from 1D ((1)H NMR, (13)C NMR, DEPT-(13)C NMR) and 2D (COSY, HMQC, HMBC) NMR analysis and the relative stereochemical assignments based on 1D NOESY correlations and analysis of coupling constants. Compounds 1 and 2 displayed potent cytotoxic activity against a panel of human cancer cell lines.     

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.     

Spiranoid withanolides from Jaborosa odonelliana

Six new spiranoid withanolides, (20R,22R,23S)-5alpha-chloro-6beta,12beta,17beta,22-tetrahydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (2), (20R,22R,23S)-5beta,6beta-epoxy-12beta,17beta,22-trihydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (3), (20R,22R,23S)-5beta,6beta-epoxy-4beta,12beta,17beta,22-tetrahydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (4), (20R,22R,23S)-5alpha,6beta,12beta,17beta,22-pentahydroxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (5), (20R,22R,23S)-6beta,12beta,17beta,22-tetrahydroxy-5alpha-methoxy-1-oxo-12,23-cycloergosta-2,24-dien-26,23-olide (6), and (20R,22R,23S)-6beta,12beta,17beta,22-tetrahydroxy-2alpha,5alpha-epidioxy-1-oxo-12,23-cycloergosta-3,24-dien-26,23-olide (7), were isolated from the leaves of Jaborosa odonelliana. Compounds 2-7 were characterized by a combination of spectroscopic methods (1D and 2D NMR, MS) and molecular modeling.     

Cytotoxic furostanol saponins and a megastigmane glucoside from tribulus parvispinus

Two new furostanol saponins, (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostan-2alpha,3beta,22alpha,26-tetraol 3-O-{beta-D-galactopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside} (1) and (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostan-3beta,22alpha,26-triol 3-O-{beta-D-galactopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside} (2), and their O-methyl derivatives (3 and 4), and a new megastigmane glucoside, (6S,7E,9xi)-6,9,10-trihydroxy-4,7-megastigmadien-3-one 10-O-beta-D-glucopyranoside (6), along with one known spirostanol saponin, gitonin (5), and four known megastigmane glucosides were isolated from the aerial parts of Tribulus parvispinus. Their structures were established by detailed spectroscopic analysis. The cytotoxic activities of 1-6 against U937, MCF7, and HepG2 cells were evaluated. Compounds 2 (IC(50) 0.5 microM) and 5 (IC(50) 0.1 microM) showed the highest activity against U937 cells.     

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.     

Acetals of three new cycloartane-type saponins from Egyptian collections of Astragalus tomentosus

Three new cycloartane-type saponin ethyl acetals, deacetyltomentoside I (2), tomentoside III (3), and tomentoside IV (4), were isolated along with the known acetal tomentoside I (1) from the aerial parts of Astragalus tomentosus of Egyptian origin. The saponins from which the acetals are most probably derived are also new compounds. The structures of the acetals were established as 6alpha-hydroxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-beta-d-xyloside (2), 6alpha-acetoxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-[beta-d-(4'-trans-2-butenoyl)]xyloside (3), and 6alpha-acetoxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-[beta-d-glucopyranosyl(1 --> 2)]-beta-d-xyloside (4), by detailed spectroscopic and chemical studies.     

Squarroside C, a new cycloartene bisdesmoside from Thalictrum squarrosum

Squarroside C (1), a new cycloartane 3,21-bisdesmoside, was isolated from the above-ground parts of Thalictrum squarrosum. The structure of 1 was established as 3-O-[O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-21-O-be ta-D-glucopyranosyl-21(S),22(S),23(R),3beta,21alpha,22beta, 30-tetrahydroxy-21,23-epoxycycloart-24-ene by 2D NMR spectroscopy and FABMS.     

Sulfated pregnane glycosides from Periploca graeca

Six new pregnane glycosides, four of them sulfated derivatives, were isolated from small branches of Periploca graeca. The compounds were identified as 16alpha-[(6-O-sulfo-beta-D-glucopyranosyl)oxy]pregn-5-en-20-ol-3beta-yl O-(2-O-acetyl-beta-D-digitalopyranosyl)-(1-->4)-beta-D-cymaropyranoside (1), 16alpha-[(6-O-sulfo-beta-D-glucopyranosyl)oxy]pregn-5-en-20-ol-3beta-yl O-beta-D-oleandropyranosyl-(1-->4)-beta-D-oleandropyranoside (2), 16alpha-[(6-O-sulfo-beta-D-glucopyranosyl)oxy]pregn-5-en-20-ol-3beta-yl O-beta-D-oleandropyranoside (3), 16alpha-[(6-O-sulfo-beta-D-glucopyranosyl)oxy]pregn-5-ene-3beta,20-diol (4), 20-O-[(beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->2)-beta-D-digitalopyranosyl)oxy]pregn-5-en-16beta-ol-3beta-yl O-beta-D-digitalopyranosyl-(1-->4)-beta-d-cymaropyranoside (5), and calogenin 3-O-beta-D-digitalopyranoside-20-O-beta-D-canaropyranoside (6). Three pregnane glycosides, previously reported from the genus Periploca, were also isolated. Structures were established on the basis of spectroscopic analyses, including 1D and 2D NMR experiments, HRESIMS, elemental analysis, and chemical degradation.     

A yew in Israel, new taxane derivatives

Five new taxanes, 5alpha,9alpha,10beta,13alpha-tetraacetoxy-14beta-O-(beta-d-glucopyranosyl)taxa-4(20),11-diene (1), 1beta,2alpha,9alpha,10beta-tetrahydroxy-5alpha-cinnamoyoxytaxa-4(20),11-dien-13-one (2), 2alpha,9alpha,10beta-trihydroxy-5alpha-cinnamoyoxytaxa-4(20),11-dien-13-one (3), 9alpha-acetoxy-2alpha,10beta-dihydroxy-5alpha-cinnamoyoxytaxa-4(20),11-dien-13-one (4), and 2alpha,10beta-diacetoxy-1beta,9alpha-dihydroxy-5alpha-cinnamoyoxy-3,11-cyclotaxa-4(20)-dien-13-one (5), have been identified in a Taxus baccata yew grown in Israel from seeds imported from the United States. We have also characterized 40 previously known taxanes from this plant material. The structures of the new taxanes (1-5) were rigorously established with 1D and 2D NMR data and confirmed by high-resolution FAB-mass spectrometry.     

Saponins of Allium elburzense

A phytochemical investigation of the bulbs of Allium elburzense has been undertaken, leading to the isolation of 13 furostanol and spirostanol saponins, eight of which are new, namely, elburzensosides A1/A2 (1a/1b), B1/B2 (2a/2b), C1/C2 (3a/3b), and D1/D2 (4a/4b). On the basis of spectroscopic analysis, mainly 2D NMR and mass spectrometry, and chemical methods, the structures of the new compounds were determined as furost-2alpha,3beta,5alpha,6beta,22alpha-pentol 3-O-beta-D-glucopyranosyl 26-O-beta-D-glucopyranoside (1a), furost-2alpha,3beta,5alpha,6beta,22alpha-pentol 3-O-[beta-D-glucopyranosyl-(1-->4)-O-beta-D-glucopyranosyl] 26-O-beta-D-glucopyranoside (2a), furost-2alpha,3beta,5alpha,22alpha-tetrol 3-O-beta-D-glucopyranosyl 26-O-beta-D-glucopyranoside (3a), and furost-2alpha,3beta,5alpha,22alpha-tetrol 3-O-[beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranosyl] 26-O-beta-D-glucopyranoside (4a), and the corresponding epimers at position 22 (1b-4b). Along with these compounds we have isolated the corresponding 22-O-methyl derivatives that we consider extraction artifacts. All the new elburzensosides A1/A2-D1/D2 possess as a common structural feature an OH-5alphathat is rare among furostanol saponins. The reported compounds have been isolated in large amounts, and this makes A. elburzense a prolific producer of saponins of the furostanol and spirostanol types.     

New triterpenoid saponins from Maesa japonica

New triterpenoid saponins, maejaposides A, B, C, D, and E, were isolated from the roots of Maesa japonica and were, respectively, defined to be 3-O-[beta-D-xylopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->2)-bet a-D-galactopyranosyl-(1-->3)] [beta-D-galactopyranosyl-(1-->2)]beta-D-glucuronopyranosides of 22alpha-[(Z)-2-hexenoyloxy]-13beta,28-oxido-olean++ +-16alpha, 28alpha-diol (1); 22alpha-[2'-methylbutanoyl]-13beta, 28-oxido-olean-16alpha,28alpha-diol (2a) and 22alpha-angeloyloxy-13beta,28-oxido-olean-16a lpha,28alpha-diol (2b); 21beta,22alpha-diangeloyloxy-13beta,28-oxido- olean-16alpha, 28alpha-diol (3); 21beta-angeloyloxy, 22alpha-(2'-methylbutanoyl)-13beta,28-oxido-olean++ +-16alpha, 28alpha-diol (4), and 21beta-angeloyloxy, 22alpha-[(Z)-2'-hexenoyl]-13beta,28-oxido-olean- 16alpha,28alpha-diol (5). Their structures were established on the basis of extensive NMR (DEPT, COSY, HOHAHA, HETCOR, HMBC, and NOESY) and ESIMS/MS studies, along with chemical degradation.     

1-deoxypaclitaxel and abeo-taxoids from the seeds of Taxus mairei

A new paclitaxel derivative and two new 2(3-->20)-abeo-taxoids were isolated from a methanol extract of the seeds of Taxus mairei, and their structures were established as 1-deoxypaclitaxel (1), 7beta,10beta-diacetoxy-2alpha,5alpha,13alpha-trihydroxy-2(3-->20)-abeo-taxa-4(20),11-dien-9-one (2), and 2alpha,13alpha-diacetoxy-10beta-hydroxy-2(3-->20)-abeo-taxa-4(20),6,11-triene-5,9-dione (3) on the basis of spectroscopic data analysis. Taxane 1 is the first example of a paclitaxel analogue with a C-1beta hydrogen substituent. Taxane 3 is an 2(3-->20)-abeo-taxane with a rare C-5 ketone and C-6 double bond.     

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 Bongardia chrysogonum

Two new triterpenoid saponins, 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-alph a-L-arabinopyranosyl]-hederagenin (1) and 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-alph a-L-arabinopyranosyl]-hederagenin 28-O-[beta-L-glucopyranosyl-(1-->6)-beta-L-glucopyranosyl] ester (2), together with five known saponins, were isolated from an ethanolic extract of the tubers of Bongardia chrysogonum. The structures of 1 and 2 were determined on the basis of spectroscopic studies.     

A new triterpene saponin from Pittosporum viridiflorum from the Madagascar rainforest.

A novel triterpenoid saponin, pittoviridoside (1), which possesses an unusual 2,3,4-trisubstituted glycosidic linkage, has been isolated from Pittosporum viridiflorum using the engineered yeast strains 1138, 1140, 1353, and Sc-7 for bioactivity-guided fractionation. The structure of this compound was determined to be 3-O-[beta-D-glucopyranosyl(1-->2)]-[alpha-D-arabinopyranosyl(1-->3)],[alpha-l-arabinofuranosyl(1-->4)-beta-D-glucuronopyranosyl-21-angeloyl-22-senecioylolean-12-en-3beta,15alpha,16alpha,21beta,22alpha,28-hexol by spectral, chemical, and GC analyses. This compound showed weak cytotoxicity against the A2780 human ovarian cancer cell line.     

Monoterpene glycosides and triterpene acids from Eriobotrya deflexa

A phytochemical study on a methanolic extract of leaves of Eriobotrya deflexa led to the isolation and characterization of nine terpenoid compounds. Four of these are new chemical entities, including two monoterpene glycosides, (3S)-O-alpha-L-rhamnopyranosyl-(1-->3)-[4-O-(E)-coumaroyl]-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl-linalool (1) and (3S)-O-alpha-L-rhamnopyranosyl-(1-->3)-[4-O-(Z)-coumaroyl]-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl-linalool (2), and two triterpene acids, 1beta,2alpha,19alpha-trihydroxy-3-oxo-12-ursen-28-oic acid (3) and 2alpha,3alpha,19alpha-trihydroxy-12-oleanen-28-oic acid (4). Their structures were elucidated on the basis of spectroscopic analysis. The activities of these isolates in an in vitro antiproliferation test were also determined.     

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.     

Microbial transformation of 20(S)-protopanaxatriol-type saponins by Absidia coerulea

Three 20(S)-protopanaxatriol-type saponins, ginsenoside-Rg1 (1), notoginsenoside-R1 (2), and ginsenoside-Re (3), were transformed by the fungus Absidia coerulea (AS 3.3389). Compound 1 was converted into five metabolites, ginsenoside-Rh4 (4), 3beta,2beta,25-trihydroxydammar-(E)-20(22)-ene-6-O-beta-D-glucopyranoside (5), 20(S)-ginsenoside-Rh1 (6), 20(R)-ginsenoside-Rh1 (7), and a mixture of 25-hydroxy-20(S)-ginsenoside-Rh1 and its C-20(R) epimer (8). Compound 2 was converted into 10 metabolites, 20(S)-notoginsenoside-R2 (9), 20(R)-notoginsenoside-R2 (10), 3beta,12beta,25-trihydroxydammar-(E)-20(22)-ene-6-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (11), 3beta,12beta-dihydroxydammar-(E)-20(22),24-diene-6-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (12), 3beta,12beta,20,25-tetrahydroxydammaran-6-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (13), and compounds 4-8. Compound 3 was metabolized to 20(S)-ginsenoside-Rg2 (14), 20(R)-ginsenoside-Rg2 (15), 3beta,12beta,25-trihydroxydammar-(E)-20(22)-ene-6-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (16), 3beta,12beta-dihydroxydammar-(E)-20(22),24-diene-6-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (17), 3beta,12beta,20,25-tetrahydroxydammaran-6-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (18), and compounds 4-8. The structures of five new metabolites, 10-13 and 16, were established by spectroscopic methods.