Chemical constituents from the stems of Gymnema sylvestre

AIM: To study the chemical constituents of stems of Gymnema sylvestre (Retz.) Schult. METHODS: Chromatographic techniques using silica gel, C-18 reversed phase silica gel, and prep-HPLC were used. The structures were elucidated on the basis of MS and spectroscopic analysis (1D and 2D NMR), as well as chemical methods. RESULTS: Seven compounds were isolated and their structures were elucidated as conduritol A (1), stigmasterol (2), lupeol (3), stigmasterol-3-O-beta-D-glucoside (4), the sodium salt of 22 alpha-hydroxy-longispinogenin-3-O-beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucurono-pyranosyl-28-O-alpha-L-rhamnopyranoside (5), oleanolic acid-3-O-beta-D-glucopyranosyl-(1 -> 6)-beta-D-glucopyranoside (6), and the sodium salt of 22 alpha-hydroxy-longispinogenin 3-O-beta-D-glucuronopyranosyl-28-O-alpha-L-rhamnopyranoside (7). The inhibition activities of compounds 1, 5-7 on non-enzymatic glycation of protein in vitro were evaluated. CONCLUSION: Compound 7 is a new triterpenoid saponin. It was shown that compounds 1, 5-7 have weak inhibition activities for non-enzymatic glycation of protein in vitro.