Bioactive furanocoumarins from the stems and leaves of Clausena hainanensis.

A new furanocoumarin, clauhainanin A (1), together with seven known furanocoumarins (2-8), were isolated from the stems and leaves of Clausena hainanensis. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. All known compounds (2-8) were isolated from C. hainanensis for the first time. All isolated compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro. Compounds 1-8 exhibited significant inhibitory effects with IC50 values ranging from 1.36 to 18.96 μM.