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--D-glucoside(4),the sodium salt of 22-hydroxy-longispinogenin-3-O--D-glucopyranosyl-(13)--D-glucurono-pyranosyl-28-O--L-rhamnopyranoside(5),oleanolic acid-3-O--D-glucopyranosyl-(16)--D-glucopyranoside(6),and the sodium salt of 22-hydroxy-longispinogenin 3-O--D-glucuronopyranosyl-28-O--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.