Three known pterocarpin derivatives, （-）-medicarpin （PDI）, （-）-2-hydroxy-4,9-dimethoxypterocarpan （PD2）, and 4- hydroxy-3-methoxy-8,9-methylene-dioxypterocarpan （PD3） were isolated from Canavalia maritima, for the first time. The cytotoxic and pro-apoptotic activities of （-）-medicarpin in cutured human tumor HeLa cells and its effect on NF-r,B activation were investigated. We found that PD1 inhibited NF-r,B activation by high content screening analysis, and PD1 exhibited cytotoxicity by SRB assay. In addition, we found that PD1 induced nuclear condensation and increased membrane permeability and mitochondrial transmembrane potential in HeLa cells in a dose and time dependent manner. In conclusion, our data suggested that （- ）-medicarpin was capable of inhibiting tumor cell growth in vitro and inducing apoptosis, which might be via the suppression of NF-kB activation.
