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, C18 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-β-D-glucoside(4), the sodium salt of 22α-hydroxy-longispinogenin-3-O-β-D-glucopyranosyl-(1→3)-β-D-glucurono-pyranosyl-28-O-α-L-rhamnopyranoside(5), oleanolic acid-3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside(6), and the sodium salt of 22α-hydroxy-longispinogenin 3-O-β-D-glucuronopyranosyl-28-O-α-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.