Oleanolic Acid Glycosides from Scabiosa caucasica and Scabiosa ochroleuca: Structural Analysis and Cytotoxicity.

In the field of research on medicinal plants from the Armenian flora, the phytochemical study of two Scabiosa L. species, S. caucasica M. Bieb. and S. ochroleuca L. (Caprifoliaceae), has led to the isolation of five previously undescribed oleanolic acid glycosides from an aqueous-ethanolic extract of the roots: 3-O-α-L-rhamnopyranosyl-(1→3)-ß-D-glucopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid 28-O-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl ester, 3-O-ß-D-xylopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-ß-D-glucopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid 28-O-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl ester, 3-O-ß-D-xylopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-ß-D-glucopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, 3-O-ß-D-xylopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-ß-D-xylopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid 28-O-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl ester, 3-O-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid 28-O-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl ester. Their full structural elucidation required extensive 1D and 2D NMR experiments, as well as mass spectrometry analysis. For the biological activity of the bidesmosidic saponins and the monodesmosidic saponin, their cytotoxicity on a mouse colon cancer cell line (MC-38) was evaluated.

An Overview of Traditional Uses, Phytochemical Compositions and Biological Activities of Edible Fruits of European and Asian Cornus Species.

Cornus species are widely distributed in central and southern Europe, east Africa, southwest Asia, and America. Several species are known for edible fruits, especially Cornus mas and Cornus officinalis. These delicious fruits, characterized by their remarkable nutritional and biological values, are widely used in traditional medicine. In contrast to the other edible Cornus species, C. mas and C. officinalis are the most studied for which little information is available on the main phytochemicals and their biological activities. Fruits are characterised by several classes of secondary metabolites, such as flavonoids, phenolic acids, lignans, anthocyanins, tannins, triterpenoids, and iridoids. The available phytochemical data show that the different classes of metabolites have not been systematically studied. However, these edible species are all worthy of interest because similarities have been found. Thus, this review describes the traditional uses of Cornus species common in Europe and Asia, a detailed classification of the bioactive compounds that characterize the fruits, and their beneficial health effects. Cornus species are a rich source of phytochemicals with nutritional and functional properties that justify the growing interest in these berries, not only for applications in the food industry but also useful for their medicinal properties.

Oleanane-type glycosides isolated from the trunk barks of the Central African tree Millettia laurentii.

Seven previously undescribed oleanane-type glycosides were isolated from the trunk barks of a Central African tree named Millettia laurentii De Wild (Fabaceae). After the extraction from the barks, the isolation and purification of these compounds were achieved using various solid/liquid chromatographic methods. Their structures were established mainly by 1D and 2D NMR (COSY, TOCSY, ROESY, HSQC, HMBC) and mass spectrometry (ESI-MS), as 3-O-ß-D-glucuronopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosylechinocystic acid, 3-O-ß-D-apiofuranosyl-(1 â†’ 3)-ß-D-glucuronopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosylechinocystic acid, 3-O-ß-D-apiofuranosyl-(1 â†’ 3)-ß-D-galactopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosylechinocystic acid, 3-O-ß-D-apiofuranosyl-(1 â†’ 3)-[ß-d-xylopyranosyl-(1 â†’ 2)]-ß-D-galactopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosylechinocystic acid, 3-O-ß-D-apiofuranosyl-(1 â†’ 3)-[α-L-arabinofuranosyl-(1 â†’ 2)]-ß-D-galactopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosylechinocystic acid, 3-O-α-L-arabinofuranosyl-(1 â†’ 2)-ß-D-galactopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosyloleanolic acid, 3-O-ß-D-apiofuranosyl-(1 â†’ 3)-[α-L-arabinofuranosyl-(1 â†’ 2)]-ß-D-galactopyranosyl-(1 â†’ 2)-ß-D-glucuronopyranosyloleanolic acid. In addition, the cytotoxicity of six glycosides among the isolated ones, was evaluated against 4 T1 cell line from a mouse mammary gland tissue, using MTS method.

Triterpenoid Saponins from the Cultivar "Green Elf" of Pittosporum tenuifolium.

Four oleanane-type glycosides were isolated from a horticultural cultivar "Green Elf" of the endemic Pittosporum tenuifolium (Pittosporaceae) from New Zealand: three acylated barringtogenol C glycosides from the leaves, with two previously undescribed 3-O-ß-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-ß-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, 3-O-ß-d-galactopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-ß-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and the known 3-O-ß-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-ß-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C (Eryngioside L). From the roots, the known 3-O-ß-d-glucopyranosyl-(1→2)-ß-d-galactopyranosyl-(1→2)-ß-d-glucuronopyranosyloleanolic acid (Sandrosaponin X) was identified. Their structures were elucidated by spectroscopic methods including 1D- and 2D-NMR experiments and mass spectrometry (ESI-MS). According to their structural similarities with gymnemic acids, the inhibitory activities on the sweet taste TAS1R2/TAS1R3 receptor of an aqueous ethanolic extract of the leaves and roots, a crude saponin mixture, 3-O-ß-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-ß-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and Eryngioside L were evaluated.

Anti-phytopathogen terpenoid glycosides from the root bark of Chytranthus macrobotrys and Radlkofera calodendron.

Chytranthus macrobotrys and Radlkofera calodendron are two Sapindaceae characterized by a lack of phytochemical data. Both root barks from the two Sapindaceae species were processed by ethanol extraction followed by the isolation of their primary constituents by liquid chromatography. This process yielded four previously undescribed terpenoid glycosides together with eight known analogues. Extracts and isolated compounds from C. macrobotrys and R. calodendron were then screened for antimicrobial activity against fifteen phytopathogens. The biological screening also involved extracts and pure compounds from Blighia unijugata and Blighia welwitschii, two Sapindaceae previously studied by our group. Phytopathogens were chosen based on their economic impact on agriculture worldwide. The selection was composed primarily of fungal species including; Pyricularia oryzae, Gaeumannomyces graminis var. tritici, Zymoseptoria tritici, Fusarium oxysporum, Botrytis cinerea, Pythium spp., Trichoderma spp. and Rhizoctonia solani. Furthermore, pure terpenoid glycosides were tested for the first time against wood-inhabiting phytopathogens such as; Phaeomoniella chlamydospora, Phaeoacremonium minimum, Fomitiporia mediterranea, Eutype lata and Xylella fastidiosa. Raw extracts exhibited different levels of activity dependent on the organism. Some pure compounds, including 3-O-α-L-arabinopyranosyl-(1 â†’ 4)-ß-D-xylopyranosyl-(1 â†’ 3)-α-L-rhamnopyranosyl-(1 â†’ 2)-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1 â†’ 2)-α-L-arabinopyranosylhederagenin (α-hederin), 3-O-ß-D-glucopyranosyl-(1 â†’ 3)-α-L-rhamnopyranosyl-(1 â†’ 2)-α-L-arabinopyranosylhederagenin (macranthoside A) and 3-O-α-L-arabinopyranosyl-(1 â†’ 3)-α-L-rhamnopyranosyl-(1 â†’ 2)-α-L-arabinopyranosylhederagenin (clemontanoside C), exhibited significant growth inhibitions on Pyricularia oryzae, Gaeumannomyces graminis var. tritici, Fomitiporia mediterranea and Zymoseptoria tritici. Monodesmoside triterpene saponins, in particular, exhibited MIC (IC100) values as low as 25 µg/ml and IC50 values as low as 10 µg/ml against these phytopathogens. Structure-activity relationships, as well as plant-microbe interactions, were discussed.

A review on the phytopharmacological studies of the genus Polygala.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Polygala, the most representative genus of the Polygalaceae family, comprises more than 600 species from all over the world of which around 40 are distributed in China, some of them, being used in the Traditional Chinese Medicine system. AIM OF THE REVIEW: We intend to discuss the current knowledge about the traditional uses, and the newest phytochemical and pharmacological achievements with tentative elucidation of the mechanism of action on the genus Polygala covering the period 2013-2019 to provide a scientific support to the traditional uses, and to critically analyze the reported studies to obtain new insights for further researches. MATERIALS AND METHODS: The data were systematically collected from the scientific electronic data bases including SciFinder, Scopus, Elsevier, PubMed and Google Scholar. RESULTS: This literature overview reported several traditional uses of different species of Polygala, mainly against wounds, inflammation, cardiovascular and central nervous system disorders. P. altomontana, P caudata, P. flavescens, P. glomerata, P. japonica, P. molluginifolia, P. sibirica, P. tenuifolia are the main species which have been studied in the last few years. Phytochemical studies showed that they contain triterpene saponins, triterpenes, terpenoids, xanthones, flavonoids, coumarins, oligosaccharide esters, styryl-pyrones, benzophenones, and polysaccharides. Pharmacological in vitro and in vivo studies and proposal of the mechanisms of action indicated that pure constituents and extracts of Polygala ssp exhibited significant anti-inflammatory, neuroprotective, antiischemic, antidepressant, sedative, analgesic, antiatherosclerosis, antitumor and enzyme inhibitory properties. CONCLUSION: This review on traditional uses and phytopharmacological potential of the genus Polygala revealed updated insights which can be explored for further mechanism-based pharmacological activities and structure/activity relationships studies and a better comprehension of the development of Chinese medicine preparations. However some pharmacological studies showed several gaps such as incomplete methodologies and ambiguous findings. More high scientific quality preclinical studies with pharmacokinetic considerations will be required in the future to assess the traditional uses of some species of this genus. This might lead to efficacy and safety issues in clinical trials and to potential medicinal applications.

Cytotoxic glycosides from the roots of Weigela x "Bristol Ruby".

Seven oleanane-type glycosides were extracted and isolated by various chromatographic methods from the roots of Weigela x "Bristol Ruby" (1-7), six previously undescribed (1-6) and a known one (7). Their structures were assigned by spectroscopic analysis mainly 2D NMR and mass spectrometry (ESIMS). Selected triterpenoid glycosides (1-3, 6, 7) displayed a good cytotoxic activity against a mouse colon cancer cell line CT26.

Oleanane-type glycosides from the roots of Weigela florida "rumba" and evaluation of their antibody recognition.

Three triterpene glycosides were isolated from the roots of Weigela florida "rumba" (Bunge) A. DC.: two previously undescribed 3-O-ß-d-xylopyranosyl-(1→2)-[ß-d-xylopyranosyl-(1→4)]-ß-d-xylopyranosyl-(1→4)-ß-d-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyloleanolic acid (1) and 3-O-ß-d-xylopyranosyl-(1→2)-[ß-d-glucopyranosyl-(1→4)]-ß-d-xylopyranosyl-(1→4)-ß-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid (2), and one isolated for the first time from a natural source 3-O-ß-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyloleanolic acid (3). Their structures were elucidated mainly by 2D NMR spectroscopic analysis (COSY, TOCSY, NOESY, HSQC, HMBC) and mass spectrometry. Compounds 2 and 3 were further evaluated as antigens in enzyme-linked immunosorbent assay (ELISA) to recognize IgM antibodies in multiple sclerosis (MS) patients' sera.

Oleanane-type glycosides from Pittosporum tenuifolium "variegatum" and P. tenuifolium "gold star".

The phytochemical study of two cultivars of Pittosporum tenuifolium Banks & Sol. ex Gaertn, "variegatum" and "gold star", led to the isolation of eight oleanane-type glycosides: seven previously undescribed and a known one. Their aglycons are oxygenated oleanane derivatives as barringtogenol C, camelliagenin A, hederagenin, and 22α-hydroxyoleanolic acid. Their structures were established by 2D NMR spectroscopic techniques and mass spectrometry as 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinopyranosyl-(1 â†’ 3)]-ß-D-glucuronopyranosyl-21-O-angeloyl-22-O-acetylbarringtogenol C, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinopyranosyl-(1 â†’ 3)]-ß-D-glucuronopyranosyl-21,22-di-O-angeloylbarringtogenol C, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinopyranosyl-(1 â†’ 3)]-ß-D-glucuronopyranosyl-22-O-angeloylcamelliagenin A, 3-O-ß-D-glucopyranosyl-(1 â†’ 2)-[ß-D-glucopyranosyl-(1 â†’ 6)]-ß-D-glucopyranosyl-22-O-[(6-O-acetyl)-ß-D-glucopyranosyl]camelliagenin A, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinofuranosyl-(1 â†’ 4)]-ß-D-glucuronopyranosylhederagenin 28-O-ß-D-glucopyranosyl ester, 3-O-α-L-arabinofuranosyl-(1 â†’ 4)-ß-D-glucuronopyranosylhederagenin 28-O-ß-D-glucopyranosyl ester, 3-O-ß-D-galactopyranosyl-(1 â†’ 2)-[α-L-arabinofuranosyl-(1 â†’ 4)]-ß-D-glucuronopyranosyl-22α-hydroxyoleanolic acid 28-O-ß-D-glucopyranosyl ester, and the known ilexoside XLIX. These results represent a significative contribution to the chemotaxonomy of the genus Pittosporum, highlighting hederagenin-type saponins as chemotaxonomic markers of P. tenuifolium cultivars.

New pregnane and phenolic glycosides from Solenostemma argel.

From the aerial parts, pericarps and roots of Solenostemma argel, three new pregnane glycosides (1-3) with two known ones and a new phenolic glycoside (4) have been isolated. Their structures were established by extensive 1D - and 2D NMR and mass spectroscopic analysis. The cytotoxicity of all compounds was evaluated against two human tumor cell lines (SW 480, MCF-7), but none of them was active in the concentration range 0.9-59.0µM. Compounds 2 and the known argeloside F at non toxic concentrations for the PBMCs (27.3µM and 27.6µM, respectively) significantly decreased the Il-1ß production by LPS-stimulated PBMCs. All isolated compounds showed a significant antioxidant potential with ORAC values in the concentration range 3481-9617µmoleq. Trolox/100g.

Triterpenoid Saponins from the Caryophyllaceae Family Modulate the Efflux Activity of the P-Glycoprotein in an In Vitro Model of Intestinal Barrier.

The oral bioavailability of drugs is often limited due to the presence of the P-glycoprotein, an efflux pump strongly expressed on the luminal side of the intestinal barrier. In an attempt to circumvent drug efflux, strategies consisting in the coadministration of drugs with surface-active agents have been found to be promising. In this context, the role of saponins on the intestinal permeability of a P-glycoprotein substrate was investigated. The P-glycoprotein inhibition activity of three triterpenoid saponins extracted from several plants of the Caryophyllaceae family was evaluated using an intestinal barrier model comprised of Caco-2 cell lines. The results showed a strong effect of two saponins on P-glycoprotein-mediated transport. At a concentration of 15 µM, the efflux ratio was close to 1 for both saponins, thus suggesting a total inhibition of the efflux pump in contrast to verapamil HCl, a conventional P-glycoprotein inhibitor. In addition, measurements of the transepithelial electrical resistance revealed that the integrity of the monolayers was not altered at such concentrations, thereby reducing potential adverse effects. The presence of acetylated sugars in the saponin structure could possibly facilitate interactions with the efflux pump by an ATP-dependent mechanism or by fluidization of cell membranes.

Cycloartane-Type Saponins from Astragalus tmoleus var. tmoleus.

Five known cycloartane-type glycosides were isolated from the roots of A. tmoleus Boiss. var. tmoleus. The identification of these compounds was mainly achieved by 1D and 2D NMR spectroscopic techniques and FABMS. The results of our studies confirm that triterpene saponins with the cycloartane-type skeleton might be chemotaxonomically significant for the genus Astragalus.

A New Aromatic Compound from the Stem Bark of Terminalia catappa.

A new aromatic compound 3,4,5-trimethoxyphenyl-1-O-(4-sulfo)-ß-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3-O-ß-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Their cytotoxicity and antiinflammatory activity, together with the antioxidant capacity of compound 1 were also evaluated.

Spirostane-type saponins from Dracaena fragrans "Yellow Coast".

Three steroidal glycosides were isolated from the bark of Dracaena fragrans (L.) Ker Gawl. "Yellow Coast", and a fourth from the roots and the leaves. Their structures were characterized on the basis of extensive 1D and 2D NMR experiments and mass spectrometry, and by comparison with NMR data of the literature. These saponins have the spirostane-type skeleton and are reported in this species for the first time.

Steroidal saponins from Dioscorea preussii.

Three new steroidal saponins, named diospreussinosides A-C (1-3), along with two known ones (4, 5) were isolated from rhizomes of Dioscorea preussii. Their structures were elucidated mainly by 1D and 2D NMR spectroscopic analysis and mass spectrometry as (25S)-17α,25-dihydroxyspirost-5-en-3ß-yl-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranoside (1), (25S)-17α,25-dihydroxyspirost-5-en-3ß-yl-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (2), and (24S,25R)-17α,24,25-trihydroxyspirost-5-en-3ß-yl-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside (3). The spirostane-type skeleton of compound 3 possessing an unusual dihydroxylation pattern on the F-ring is reported for the first time. Cytotoxicity of compounds 2-5 was evaluated against two human colon carcinoma cell lines (HT-29 and HCT 116).

Cytotoxic steroidal glycosides from Allium flavum.

Three new spirostane-type glycosides (1-3) were isolated from the whole plant of Allium flavum. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25R)-2α-hydroxyspirost-5-en-3ß-yl O-ß-D-xylopyranosyl-(1→3)-[ß-D-galactopyranosyl-(1→2)]-ß-D-galactopyranosyl-(1→4)-ß-D-galactopyranoside (1), (20S,25R)-2α-hydroxyspirost-5-en-3ß-yl O-ß-D-xylopyranosyl-(1→3)-[ß-D-glucopyranosyl-(1→2)]-ß-D-galactopyranosyl-(1→4)-ß-D-galactopyranoside (2), and (20S,25R)-spirost-5-en-3ß-yl O-α-L-rhamnopyranosyl-(1→4)-[ß-D-glucopyranosyl-(1→2)]-ß-D-glucopyranoside (3). The three saponins were evaluated for cytotoxicity against a human cancer cell line (colorectal SW480).

New triterpenoid estersaponins from the root barks of Pittosporum verticillatum subsp. verticillatum and evaluation of cytotoxicities.

The phytochemical investigation of the root barks of Pittosporum verticillatum Bojer subsp. verticillatum led to the isolation of three new triterpene saponins, 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-(2-acetoxy-2-methylbutanoyl)-R1-barrigenol (1), 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-(2-acetoxy-2-methylbutanoyl)-28-O-acetyl-R1-barrigenol (2), 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-ß,ß-dimethylacryloyl-22-O-angeloyl-R1-barrigenol (3), and one known saponin senaciapittoside B (4). Their structures were elucidated mainly by 1D- and 2D-NMR spectroscopy and HRESIMS. Compounds 1-4 were evaluated for their cytotoxicity against one human cancer cell line (SW480) and one rat cardiomyoblast cell line (H9c2).

Steroidal saponins from Dracaena marginata.

Three new steroidal saponins and ten known ones were isolated from the bark of Dracaena marginata, along with two known steroidal saponins from the roots. Their structures were elucidated on the basis of extensive 1D and 2D NMR experiments and mass spectrometry as (25R)-26-(beta-D-glucopyranosyloxy)3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-rhamnopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (1), (25R)-26-(beta-D-glucopyranosyloxy)-3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (2), and (25S)-3beta-hydroxyspirost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (3).

Steroidal saponins from the fruits of Solanum torvum.

Seven steroidal glycosides have been isolated from the fruits of Solanum torvum Swartz. Their structures were established by 2D NMR spectroscopic techniques ((1)H,(1)H-COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as (25S)-26-(ß-D-glucopyranosyloxy)-3-oxo-5α-furost-20(22)-en-6α-yl-O-ß-D-xylopyranoside (1), (25S)-26-(ß-D-glucopyranosyloxy)-3-oxo-22α-methoxy-5α-furostan-6α-yl-O-ß-D-xylopyranoside (2), (25S)-26-(ß-D-glucopyranosyloxy)-3ß-hydroxy-22α-methoxy-5α-furostan-6α-yl-O-α-L-rhamnopyranosyl-(1→3)-ß-D-glucopyranoside (3), (25S)-3ß-hydroxy-5α-spirostan-6α-yl-O-ß-D-xylopyranoside (4), (25S)-3-oxo-5α-spirostan-6α-yl-O-ß-D-xylopyranoside (5), (25S)-3ß-hydroxy-5α-spirostan-6α-yl-O-ß-D-glucopyranoside (6), (25S)-3ß,27-dihydroxy-5α-spirostan-6α-yl-O-ß-D-glucopyranoside (7).