Novel steroidal saponins from Dioscorea esculenta (Togedokoro).

Fifteen steroidal saponins 1-15, which include 4 furostanol glycosides 1-3 and 15, and 11 spirostanol glycosides 4-14, were isolated from the tubers and leaves of lesser yam (Dioscorea esculenta, Togedokoro). Their structures were identified by nuclear magnetic resonance and liquid chromatography mass spectroscopy. Four steroidal saponins 9, 11, 14, and 15 were found to be novel compounds.