Steroidal glycosides from Cynanchum amplexicaule

摘要

A new C21 steroidal glycoside that has a new steroid amplexicogenin C as aglycone, together with three known steroids, were isolated from Cynanchum amplexicaule. Their structures were elucidated as amplexicogenin C-3-O-β-D-cymaropyranoside (1), cynatratoside A (2), tylophoside A (3), and cynatratoside B (4) by spectroscopic methods, including 1D and 2D NMR experiments.