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-β-D- glucopyranosyl-3β,26-diol-23(S)-methoxy-25(R)-Δ^5,20(22)-diene-furosta-3-O-［α-L-rhamnopyranosyl -(1→2)-O-α-L-rhamnopyranosyl-(1→4)］-β-D-glucopyranoside (I), pseudoprotodioscin (II), 26-O-β-D-glucopyranosyl-3β,26-diol-25(R)-Δ^5,20(22)-diene-furosta-3-O-α-L-rhamnopyranosyl-(1→2)-O-β-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.