Two new antiepilepsy compounds--otophyllosides A and B.

Two new C21 steroidal constituents, named otophylloside A(IV) and otophylloside B(V), have been isolated from the roots of Cynanchum otophyllum Schneid, whose structures have been analysed in this paper by using X-ray crystallography and spectrometric data (UV, IR, 1H- and 13C-NMR, MS) and chemical reaction. They were found to be active against epilepsy, IV and V can protect rats from audiogenic seizures (AS) and its ED50 = 10.20 mg/kg.