Identification of benzisoquinolinone derivatives with cytotoxicities from the leaves of Portulaca oleracea

Three new benzisoquinolinones (1-3), together with seven known benzisoquinolinone derivatives (4-10), were isolated from Portulaca oleracea for the first time. The structures of the isolated compounds (1-10) had been elucidated on the basis of extensive spectroscopic methods including ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance techniques and by comparison with data reported in the references. All isolated compounds were assayed for cytotoxicities against selected human lines in vitro by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Compounds 1, 2, 4, and 7 showed important cytotoxicities against HCT116, MCF-7, U87, and A549 cell lines with IC50 values in the range of 11.62-84.45 μM, which compared with positive control doxorubicin.