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.
从 Cynchum amplexicaule 中分离出一种新的 C21 甾体糖苷,它具有一种新的类固醇 amplexicogenin C 作为苷元,以及三种已知的类固醇。通过光谱方法,包括一维和二维 NMR 实验,它们的结构被阐明为 amplexicogenin C-3-O-β-D-cymaropyranoside (1)、cynatratoside A (2)、tylophoside A (3) 和 cynatratoside B (4)。