[Isolation and identification of steroidal saponins from Dioscorea panthaica Prain et Burkill].

Aim: To investigate the chemical constituents of the rhizomes of Dioscorea panthaica Prain et Burkill and look for new active compounds.
Methods: The compounds were isolated with silica gel and HPLC, and their structures were elucidated on the basis of chemical evidences and spectral analysis (IR, ESI-MS, 1HNMR, 13CNMR, DEPT, 1H-1H COSY, HMQC, HMBC, NOESY).
Results: Three steroidal saponins were isolated from the rhizomes of Dioscorea panthaica. They were elucidated as 26-O-beta-D-glucopyranosyl-3 beta, 26-diol-23(S)-methoxy-25(R)-delta 5,20(22)-diene-furosta-3-O-[alpha-L-rhamnopyranosyl-(1-->2)- O-alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (I), pseudoprotodioscin (II), 26-O-beta-D-glucopyranosyl-3 beta, 26-diol-25 (R)-delta 5,20(22)-diene-furosta-3-O-alpha-L-rhamnopyranosyl- (1-->2)-O-beta-D-glucopyranoside (III).
Conclusion: Compound I is a new steroidal saponin and was named as dioscoreside C. Compound II and III were obtained from this genus for the first time.