Cytotoxic 4-phenylcoumarins from the flowering buds of Mesua ferrea

Eleven 4-phenylcoumarins including three new 4-phenylcoumarins, mesuaferols A-C (1-3), together with eight known 4-phenylcoumarins (4-11) have been isolated from the flowering buds of Mesua ferrea. Their structures were elucidated via UV, IR, HR-ESI-MS, and NMR spectral data. Compound 9 showed moderate cytotoxic activity toward MDA-MB-231, MCF-7, HepG2 and HeLa cell lines with IC50 values of 13.68 ± 1.36 μM, 9.27 ± 1.84 μM, 21.06 ± 1.95 μM, and 7.26 ± 1.68 μM, respectively, and other compounds showed weak cytotoxicity.