Chemical Constituents from Walsura pinnata (Meliaceae)

A phytochemical study on the bark of Walsura pinnata has led to the isolation of a new oleanane triterpene acid, 3-oxo-olean-9(11),12-dien-28-oic acid (1), together with nine known compounds (2-10). Their structures were established on the basis of the detailed spectroscopic analysis, including one- and two-dimensional NMR, ESI-MS and HR-ESI-MS techniques. Compounds 2, 3, 5, 6 and 8 were isolated from W. pinnata for the first time. Compounds 3 and 4 showed in vitro growth inhibitory activity against two human cancer cell lines MCF-7 and SK-OV-3 with IC50 values within the range of 8.85 - 18.28 mu g/mL. To the best of our knowledge, this is the first report on the cytotoxic activity of compound 3 towards both cancer cell lines.