[C21 steroidal constituents from Cynanchum hancockianum].

Two new compounds hancogenin B (V) and hancoside A (VI) and four known compounds glucogenin C (I), cynatratoside A (II), glaucogenin A (III) and anhydrohirundigenin (IV) were isolated from the roots of Cynanchum hancockianum (Maxim) Al. Iljinski. Their structures were identified on the basis of spectral evidence. The fragmentation ways of 13:14, 14:15-secopregnenes in EIMS were outlined and the antitumor activity of II and the antiendotoxic activity of VI were also preliminarily tested in vitro.