New Chlorine‐Containing Sesquiterpenoid from <i>Artemisia Blepharolepis</i>

One new chlorinated sesquiterpenoid (compound 1, ablepharolide) and twenty-one known compounds were obtained from the aerial parts of Artemisia blepharolepis. Their structures were established by spectroscopic methods and the absolute configuration was further determined by single-crystal X-ray diffraction analysis for ablepharolide. Ablepharolide is a rare sesquiterpenoid with a 4-methyl-7-isopropyl-9-ethyl-perhydroindene skeleton that incorporates a chlorine atom. It significantly inhibited the growth of MCF-7 cells with IC₅₀ value of 8.34±0.77 μM. Further investigations demonstrated that ablepharolide induced morphological changes in MCF-7 cells, inhibited proliferation in a time- and dose-dependent manner. Furthermore, western blot analysis revealed that ablepharolide induced a significant increase in cleaved caspase-8, cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) in MCF-7 cells. All of these results supported that ablepharolide induced exogenous apoptosis in MCF-7 cells.