Study of steroidal saponins in Dioscorea zingiberensis C.H.Wright.

Abstract

Six steroidal saponins, isolated by a series of chromatographic separations from the rhizomes of Dioscorea zingiberensis C.H.Wright, were characterized as dioscin (1), gracillin (2), Zingiberensis Newsaponin (3), β-sitosterol-3-O-β-D-glucoside (4), them, compound 5 and 6 were new compounds. The purification and the structure characterization of these compounds were described. The isolated compounds and the total saponins were evaluated for their activity in vitro of relaxation to the blood vessel, and the results indicated that their pharmacologic activities in vitro were statistically significant. The relaxation rate of compound 5 is 35.4%±9.2%, which is the strongest among all the compounds. The experimental data and analytic results were described.