Studies on the Steroidal Saponins of Dioscorea tokoro Makino Collected from Zhejiang

Six steroidal saponins were isolated from rhizome of Dioscorea tokoro Makino (collected from Zhejiang). By means of acetylation, acid hydrolysis, IR, MS, and 13C-NMR etc., five of them were identical with yononin (A) (yield 0.0069%), dioscin (C) (0.04%), gracillin (D) (0.03%), protodioscin (E) (0.5%), protogracillin (F) (0.2%), respectively. Because of low yield, saponin B was not identified.