抄録
The structures of two steroidal substances, G1 and SE1, isolated from the fresh aerial parts of Dioscorea tenuipes FRANCH. et SAVAT. (Dioscoreaceae), were investigated. G1 (mp 221-222°, [α]D -10.0°, C29H46O6) and SE1 (mp 172-174°(decomp.), [α]D +134.4°, C36H60O12·2H2O, Ehrlich reaction +) were characterized as diotigenin 4-acetate (I) and the corresponding furostanol 26-O-glucoside, 4β-acetoxy-22-methoxy-5β-furostane-2β, 3α, 26-triol 26-O-β-D-glucopyranoside (VIII), respectively. VIII is the first reported furostanol glucoside corresponding to spirostanol acetate and is most likely to have been formed secondarily from the 22-hydroxy analog (IX), mp 165-166°(decomp.). IX is regarded as the prototype compound of I. The mass spectrum of VIII and compositions of the major fragment ions are presented.
