Abstract:From the roots of Silene szechuensis, a folk herb of Yunnan named "wa cao", three new cyclopeptides silenins A-C were isolated. The structures were elucidated by the spectral and chem-ical methods as silenin A-cyclo-(Pro-Leu-Ser-Phe- silenin B-cyclo-(Phe-Leu-Ala-Pro-Leu-Pro-Phe-Pro), silenin C--- cyclo- (Tyr-Ala-Phe-Pro-Gly-Phe- Tyr-Pro).