Structurally Novel C-17-Sesquiterpene Lactones From Ainsliaea Pertyoides

Pertyolides A (1) and B (2), two unprecedented C-17-eudesmanolides with extended side chains, and one rare C-17-guaianolide, pertyolide C (3), along with 15 known sesquiterpene lactones were isolated from the whole plant of Ainsliaea pertyoides. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of compound 1 was assigned by X-ray crystallography. All isolates were evaluated for their cytotoxic activities against four human tumor cell lines A549, HCT116, MGC803, CCRF-CEM, and only alantolactone (5) showed significant inhibitions against the tumor cell lines tested.