Steroidal Glycosides from the Root of Cynanchum caudatum M.

Novel steroidal glycosides 2-4, 6-11, 13-19 and 20 were isolated from the roots of Cynanchum caudatum M. (Asclepiadaceae). The structures of these steroidal glycosides were determined on the basis of spectral and chemical evidence. All of these glycosides contain 2, 6-dideoxyhexopyranoses as component sugars, and their structures were elucidated as esterified pregnane-type.