Abstract: From the seeds of Vaccaria Segtalis, a well-known traditional Chinese medicine named "wang bu liu xing", four cyclopeptides vaccarins A-D were isolated in which only vaccarin A is a new cyclopeptide. Their structures were elucidated by spectral and chemical methods as vaccarin A—— cyclo--(Trp-Ala -Gly- Val- Ala vaccarin B ——- cyclo--Pro-Gly- Leu Ser-Phe- Ala--Phe), vaccarin C——cyclo-(Pro --Gly- Tyr- Val-Pro-Leu-Trp),ccarin D- rtyclo-(Pro-Val-Trp-Ala-Gly-Val).

Key words: Vaccaria segetalis