Anne Claire Mitaine-Offer

Structure and cytotoxicity of steroidal glycosides from Allium schoenoprasum

A phytochemical analysis of the whole plant of Allium schoenoprasum, has led to the isolation of four spirostane-type glycosides (1-4), and four known steroidal saponins. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25S)-spirost-5-en-3β,12β,21-triol 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (1), (20S,25S)-spirost-5-en-3β,11α,21-triol 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (2), laxogenin 3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-D-glucopyranoside (3), and (25R)-5α-spirostan-3β,11α-diol 3-O-β-D-glucopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→4)]-β-D-galactopyranoside (4). Four of the isolated compounds were tested for cytotoxic activity against the HCT 116 and HT-29 human colon cancer cell lines.

Triterpenoid saponins from Polycarpaea corymbosa Lamk. var. eriantha Hochst

Four triterpenoid saponins (1-4) were isolated from Polycarpaea corymbosa Lamk. var. eriantha Hochst along with the known apoanagallosaponin IV (5). Their structures were elucidated by spectroscopic data analysis. Among the compounds 1, 3-5 which were evaluated for their cytotoxicity against three tumor cell lines (SW480, DU145 and EMT6), compound 1 exhibited cytotoxicity with IC50 values ranging from 4.61 to 22.61 μM, which was greater than that of etoposide. Compound 2 was tested only against SW480 and a cardiomyoblast cell line (H9c2), and was inactive.

Triterpenoid saponins from the roots of two Gypsophila species.

Two triterpenoid saponins with two known ones have been isolated from the roots of Gypsophila arrostii var. nebulosa, and two new ones from the roots of Gypsophila bicolor. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosylquillaic acid 28-O-β-d-xylopyranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-β-d-fucopyranosyl ester (1), 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosylgypsogenin 28-O-β-d-xylopyranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-β-d-fucopyranosyl ester (2), 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosylgypsogenin 28-O-β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-[(4-O-acetyl)-β-d-quinovopyranosyl-(1→4)]-β-d-fucopyranosyl ester (3), gypsogenic acid 28-O-β-d-glucopyranosyl-(1→3)-{6-O-[3-hydroxy-3-methylglutaryl]-β-d-glucopyranosyl-(1→6)}-β-d-galactopyranosyl ester (4). Three compounds were evaluated against one human colon cancer cell line SW480 and one rat cardiomyoblast cell line H9c2.

Triterpene saponins from Eryngium kotschyi

Four new oleanane-type saponins 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyl-22-O-β,β-dimethylacryloylA1-barrigenol (1), 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol (2), 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 6)]-β-D-glucopyranosyl-21,22,28-O-triacetyl-(3β,21β,22α)-olean-12-en-16-one (3), and 3-O-β-D-glucopyranosyl-(1 → 2)-glucopyranosyl-22-O-β-D-glucopyranosylsteganogenin (4), along with the known 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol and 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyloleanolic acid, were isolated from a methanol extract of the roots of Eryngium kotschyi by multiple chromatographic steps. Saponins 3 and 4 are unusual by the original structure of their aglycon. Compound 3 possessed an oleanane-type skeleton with a 21,22,28-triacetylation and a ketone function at the C-16 position. For compound 4, the 17,22-seco-oleanolic acid skeleton is rarely found in natural saponins.

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-(β-D-glucopyranosyloxy)-3-oxo-5α-furost-20(22)-en-6α-yl-O-β-D-xylopyranoside (1), (25S)-26-(β-D-glucopyranosyloxy)-3-oxo-22α-methoxy-5α-furostan-6α-yl-O-β-D-xylopyranoside (2), (25S)-26-(β-D-glucopyranosyloxy)-3β-hydroxy-22α-methoxy-5α-furostan-6α-yl-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranoside (3), (25S)-3β-hydroxy-5α-spirostan-6α-yl-O-β-D-xylopyranoside (4), (25S)-3-oxo-5α-spirostan-6α-yl-O-β-D-xylopyranoside (5), (25S)-3β-hydroxy-5α-spirostan-6α-yl-O-β-D-glucopyranoside (6), (25S)-3β,27-dihydroxy-5α-spirostan-6α-yl-O-β-D-glucopyranoside (7).

Oleanolic acid and hederagenin glycosides from Weigela stelzneri.

Four previously undescribed and one known oleanolic acid glycosides were isolated from the roots of Weigela stelzneri, and one previously undescribed and three known hederagenin glycosides were isolated from the leaves. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-β-D-xylopyranosyl-(1 → 6)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranosyl ester. The majority of the isolated compounds were evaluated for their cytotoxicity against two tumor cell lines (SW480 and EMT-6), and for their anti-inflammatory activity. The compounds 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid and 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid exhibited the strongest cytotoxicity on both cancer cell lines. They revealed a 50% significant inhibitory effect of the IL-1β production by PBMCs stimulated with LPS at a concentration inducing a very low toxicity of 23% and 28%, respectively.

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-1β production by LPS-stimulated PBMCs. All isolated compounds showed a significant antioxidant potential with ORAC values in the concentration range 3481-9617μmoleq. Trolox/100g.

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-3β-yl-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside (1), (25S)-17α,25-dihydroxyspirost-5-en-3β-yl-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (2), and (24S,25R)-17α,24,25-trihydroxyspirost-5-en-3β-yl-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-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).

Terpenoid glycosides from the root's barks of Eriocoelum microspermum Radlk. ex Engl.

Eight undescribed triterpenoid saponins together with a known one, and two undescribed sesquiterpene glycosides were isolated from roots barks of Eriocoelum microspermum. Their structures were elucidated by spectroscopic methods including 1D and 2D experiments in combinaison with mass spectrometry as 3-O-α-L-rhamnopyranosyl-(1u202f→u202f3)-[α-L-rhamnopyranosyl-(1u202f→u202f2)]-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1u202f→u202f3)-[β-D-glucopyranosyl-(1u202f→u202f3)-α-L-rhamnopyranosyl-(1u202f→u202f2)]-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1u202f→u202f3)-[β-D-xylopyranosyl-(1u202f→u202f3)-α-L-rhamnopyranosyl-(1u202f→u202f2)]-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1u202f→u202f4)-[α-L-rhamnopyranosyl-(1u202f→u202f2)]-α-L-arabinopyranosylhederagenin 28-O-β-D-glucopyranosyl ester, 3-O-α-L-rhamnopyranosyl-(1u202f→u202f3)-β-D-xylopyranosyl-(1u202f→u202f4)-β-D-xylopyranosyl-(1u202f→u202f3)-α-L-rhamnopyranosyl-(1u202f→u202f2)-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1u202f→u202f3)-α-L-arabinopyranosyl-(1u202f→u202f4)-β-D-xylopyranosyl-(1u202f→u202f3)-α-L-rhamnopyranosyl-(1u202f→u202f2)-α-L-arabinopyranosylhederagenin, 3-O-β-D-xylopyranosyl-(1u202f→u202f4)-α-L-arabinopyranosyl-(1u202f→u202f4)-β-D-glucopyranosyl-(1u202f→u202f3)-α-L-rhamnopyranosyl-(1u202f→u202f2)-α-L-arabinopyranosylhederagenin, 3-O-α-L-rhamnopyranosyl-(1u202f→u202f4)-α-L-rhamnopyranosyl-(1u202f→u202f3)-α-L-arabinopyranosyl-(1u202f→u202f4)-β-D-glucopyranosyl-(1u202f→u202f3)-α-L-rhamnopyranosyl-(1u202f→u202f2)]-α-L-arabinopyranosylhederagenin, 1-O-{β-D-xylopyranosyl-(1u202f→u202f3)-[α-L-rhamnopyranosyl-(1u202f→u202f2)]-β-D-glucopyranosyl-(1u202f→u202f4)-α-L-rhamnopyranosyl-(1u202f→u202f6)}-[β-D-xylopyranosyl-(1u202f→u202f3)]-[α-L-rhamnopyranosyl-(1u202f→u202f2)]-β-D-glucopyranosyl-(2E,6E)-farnes-1-ol, 1-O-{β-D-glucopyranosyl-(1u202f→u202f3)-[α-L-rhamnopyranosyl-(1u202f→u202f2)]-β-D-glucopyranosyl-(1u202f→u202f4)-α-L-rhamnopyranosyl-(1u202f→u202f6)}-[β-D-xylopyranosyl-(1u202f→u202f3)]-[α-L-rhamnopyranosyl-(1u202f→u202f2)]-β-D-glucopyranosyl-(2E,6E)-farnes-1-ol. These results represent a contribution to the chemotaxonomy of the genus Eriocoelum highlighting farnesol glycosides as chemotaxonomic markers of the subfamily of Sapindoideae in the family of Sapindaceae.

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-β-d-xylopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→4)]-β-d-xylopyranosyl-(1→4)-β-d-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyloleanolic acid (1) and 3-O-β-d-xylopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-β-d-xylopyranosyl-(1→4)-β-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-β-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.