Two new steroidal saponins from the rhizomes of Dioscorea zingiberensis

AIM:To investigate the chemical constituents of Dioscorea zingiberensis C.H.Wright.METHODS:The compounds were isolated by various chromatographic techniques,and the structures of the new steroidal saponins were elucidated by extensive 1D-and 2D-NMR,MS,and IR spectral analysis.RESULTS:The 70% EtOH extract of the rhizomes of Dioscorea zingiberensis afforded two new steroidal saponins,zingiberenosides A(1) and B(2),along with eight known analogues,3,26-dihydroxy-25(R)-furosta-5,20(22)-diene-3-O--Lrhamnopyranosyl-(12)-O--D-glucopyranoside(3),methyl parvifloside(4),deltoside(5),methyl deltoside(6),zingiberensis new saponin(7),deltonin(8),progenin Ⅲ(9) and diosgenin-diglucoside(10).CONCLUSION:Two new steroidal saponins were isolated from Dioscorea zingiberensis and their structures determined.