4-Propyl- and 4-phenylcoumarins from mesua lepidota T. Anderson and their cytotoxic activity.

Two new 4-phenylcoumarins, mesulepidotins A (1) and B (2), one new 4-propylcoumarin, mesulepidotin C (3), and one known 4-phenylcoumarin (4) were isolated from Mesua lepidota stem barks. The structures of 4-propyl- and 4-phenylcoumarins were identified by analysing 1D and 2D NMR spectra combined with high-resolution ESIMS data. Compounds 1-4 were assayed to MCF-7 and HeLa cells for their cytotoxic activity. Mesulepidotin A (1) showed high activity with an IC50 value of 1.59 and 1.41 µM, respectively.