Saponarioside C, the first alpha-D-galactose containing triterpenoid saponin, and five related compounds from Saponaria officinalis

Six novel triterpenoid saponins, named saponariosides C-H, were isolated from the whole plants of Saponaria officinalis. Their structures were established as saponarioside C (1), 3-O-beta-D-xylopyranosyl-gypsogenic acid-28-O-alpha-D-galactopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-- >6)-[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside D (2), 3-O-beta-D-xylopyranosyl-gypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside E (3), 3-O-beta-D-glucopyranosyl-gypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside F (4), 3-O-beta-D-xylopyranosyl-16alpha-hydroxygypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside G (5), 3-O-beta-D-xylopyranosyl-16alpha-hydroxygypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->6)-[beta-D-glucopyranosyl-(1-->3 )]-beta-D-glucopyranoside; and saponarioside H (6), 3-O-beta-D-xylopyranosyl-gypsogenic acid-28-O-beta-D-glucopyranoside, by a combination of extensive NMR (DEPT, COSY, HOHAHA, HETCOR, HMBC, and NOESY) studies and chemical degradation.     

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.     

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.     

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.     

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.     

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.     

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).     

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.     

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.     

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.     

Triterpenoid saponins from Isertia pittieri.

Two new 27-nor-triterpenoid saponins, pyrocincholic acid 3 beta-O-beta-D-quinovopyranosyl-28-[beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl] ester (1) and pyrocincholic acid 3 beta-O-beta-D-quinovopyranosyl(1-->6)-beta-D-glucopyranosyl-28-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl] ester (2) were isolated from the stem bark of Isertia pittieri, together with two known bidesmosidic quinovic acid glycosides. The structures of 1 and 2 were determined on the basis of spectroscopic studies.     

Acylated preatroxigenin glycosides from Atroxima congolana

Six new acylated bisdesmosidic preatroxigenin saponins named atroximasaponins E1, E2 (1, 2), F1, F2 (3, 4), and G1, G2 (5, 6) were isolated as three inseparable mixtures of the trans- and cis-p-methoxycinnamoyl derivatives, from the roots of Atroxima congolana. Their structures were established through extensive NMR spectroscopic analysis as 3-O-beta-D-glucopyranosylpreatroxigenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->3)]-[4-O-trans-p-methoxycinnamoyl]-beta-D-fucopyranoside (atroximasaponin E1, 1), and its cis-isomer, atroximasaponin E2 (2), 3-O-beta-D-glucopyranosylpreatroxigenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[6-O-acetyl-beta-D-glucopyranosyl-(1-->3)]-[4-O-trans-p-methoxycinnamoyl]-beta-D-fucopyranoside (atroximasaponin F1, 3), and its cis-isomer, atroximasaponin F2 (4), 3-O-beta-D-glucopyranosylpreatroxigenin-28-O-beta-D-apiofuranosyl-(1-->3)-[alpha-l-rhamnopyranosyl-(1-->2)]-[4-O-trans-p-methoxycinnamoyl]-beta-D-fucopyranoside (atroximasaponin G1, 5), and its cis-isomer, atroximasaponin G2 (6), respectively.     

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.     

New triterpenoid saponins and sapogenins from Saponaria officinalis

Five new triterpenoid saponins, named saponariosides I-M, were isolated from the whole plants of Saponario officinalis. Their structures were established as saponarioside I (1) 3-O-beta-D-xylopyranosyl-16 alpha-hydroxygypsogenic acid 28-O-alpha-D-galactopyranosyl-(1-->6)-beta-D- glucopyranosyl-(1-->3)[-beta-D-glucopyranoside[, saponarioside J (3) 3-O-beta-D-xylopyranosylolean-11,13(18)-diene-23,28-dioic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)[- beta-D-glucopyranoside[, saponarioside K (4) 3,4-seco-16 alpha-hydroxygypsogenic acid 28-O-beta-D-glucopyranosyl- (1-->3)-beta-D-glucopyranosyl-(1-->6)[-beta-D-glucopyranoside[, saponarioside L (5) 3-O-beta-D-xylopyranosylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)[-beta- D- glucopyranoside[, and saponarioside M (6) 3-O-beta-D-glucopyrano-sylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1--6)-beta-D- glucopyranoside[ by NMR studies and chemical degradations. The aglycons of saponariosides J (3) and K (4) are new sapogenins.     

Matrix metalloproteinase-1 expression inhibitory compound from the whole plants of Viola ibukiana Makino

Bioassay-guided fractionation has led to the isolation of two triterpenoid saponins 3-O-[O-beta-D-glucopyranosyl-(1 --> 3)-O-beta-D-glucopyranosyl] oleanolic acid (1), and 3-O-[O-beta-D-glucopyranosyl-(1 --> 2)-O-beta-D-glucopyranosyl] oleanolic acid (2) from the whole plants of Viola ibukiana Makino. Compound 2 showed matrix metalloproteinase-1 expression inhibition activities in a dose-dependent manner.     

Three new acylated triterpene saponins from Acanthophyllum squarrosum

Three new triterpenoid saponins, 1-3, were isolated from the roots of Acanthophyllum squarrosum. Their structures were established mainly by 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-3-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)-3,4-di-O-acetyl-beta-D-fucopyranoside (1), 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[5-O-acetyl-alpha-L-arabinofuranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranoside (2), and 3-O-beta-D-glucopyranosyl-quillaic acid-28-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (3).     

Chionaeosides A-D, triterpene saponins from Paronychia chionaea

Four new triterpenoid saponins, chionaeosides A-D (1-4) were isolated from the roots of Paronychia chionaea. On the basis of their spectroscopic data, the structures of the new saponins were established as 3-O-alpha-L-arabinopyranosylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1), 3-O-alpha-L-arabinopyranosylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (2), 3-O-alpha-L-arabinopyranosylgypsogenic acid 28-O-beta-D-glucopyranoside (3), and 3-O-alpha-L-arabinopyranosylgypsogenic acid (4).     

Two new biologically active triterpene saponins from Acanthophyllum squarrosum

Two novel triterpenoid saponins (1 and 2) have been isolated from the roots of Acanthophyllum squarrosum. The structures were established mainly by a combination of 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-be ta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3 )-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L- rhamnopyranosyl-(1-->3)]-beta-D-fucopyranoside (1) and 3-O-beta-D-glucopyranosylgypsogenin-28-O-alpha-L-rhamnopyranosyl-( 1-- >2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6 )]- beta-D-glucopyranoside (2). Compound 1 showed a moderate concentration-dependent immunomodulatory effect in an in vitro lymphocyte proliferation assay.     

Two new spirostanol saponins from Allium tuberosum.

Two new spirostanol saponins, tuberosides D and E, have been isolated from the seeds of Allium tuberosum. On the basis of spectral data and chemical reactions, their structures were established as (25S)-5alpha-spirostane-2alpha,3beta-diol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-[alpha-L-rhamnopyranosyl-(1-->4 )]-O-beta-D-glucopyranoside and (25S)-5alpha-spirostan-2alpha, 3beta-diol 3-O-beta-D-glucopyranosyl-(1-->2)-O-[alpha-L-rhamnopyranosyl-(1-->4)] -O-beta-D-glucopyranoside, respectively.     

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).