Four guaia-12,6-olide type sesquiterpene lactones, aguerin B (1), 8alpha-acetoxyzaluzanin C (2), cynaropicrin (3), and deacylcynaropicrin (4), were isolated from the flowers of Hemisteptia lyrata Bunge. It is the first report on the isolation of compounds 1-4 from Hemisteptia species. All the
Two sesquiterpene lactones were isolated from Hemisteptia lyrata Bunge (Compositae). Their structures were elucidated by spectroscopic methods as recently known hemistepsin and the new 6-O-(2-methylpropenoyl)-3-hydroxy-4(15), 10(14), 11(13)-guaiatrien-12,8-olide. The two hemistepsin derivatives were