Artemyrianolides A-S, Cytotoxic Sesquiterpenoids from .

Random screening suggested that the EtOH extract of (Asteraceae) and its EtOAc fraction had cytotoxicity against HepG2 cells with inhibitory ratios of 30.6% and 53.5% at 50.0 μg/mL. Bioassay-guided isolation of the most active fractions (Fr. C and Fr. D) afforded 19 new sesquiterpenolides, artemyrianolides A-S (-), involving 13 germacranolides (-), four guaianolides (-), and two eudesmanolides ( and ), together with 16 known sesquiterpenoids (-). The new compounds were characterized by physical data analyses (HRESIMS, IR, 1D and 2D NMR, ECD), and the absolute configurations of compounds , , and were determined by X-ray crystallography. Structurally, compounds and - maintain an uncommon -fused 10/5 bicyclic system and compound possesses an unusual (7) configuration. Twenty of the compounds exhibited cytotoxicity against HepG2, Huh7, and SMMC-7721 cell lines. Compound showed cytotoxic activity on both HepG2 and Huh7 cells with IC values of 8.6 and 8.8 μM, and compounds and showed cytotoxicity to the three human hepatoma cell lines with IC values of 4.9 and 7.4 μM (HepG2), 4.3 and 7.8 μM (Huh7), and 3.1 and 9.8 μM (SMMC-7721), respectively.