Steroidal Sapogenins from Tacca leontopetaloides

Diosgenin and its ring-F-hydroxylated derivatives isonarthogenin {spirost-5-ene-3,27-diol {3beta, 22 R, 25 S)} and isonuatigenin {spirost-5-ene-3,25-diol (3beta, 22 R, 25 S)}, together with the 22,25-epoxyfurost-5-ene isomer nuatigenin {furost-5-ene-3,26-diol-22,25-epoxy (3beta, 22 R, 25 S)}, were identified as the major steroidal sapogenins of the acid hydrolysate of an extract of leaves of TACCA LEONTOPETALOIDES by IR, (1)H-NMR, (13)C-NMR, and mass spectroscopy. A diosgenin ester was isolated which apparently arose by ring closure of a glycosylated furostene during hydrolysis.