To investigate the cembranoid diterpenes from the soft coral Sarcophyton sp. collected in the South China Sea. Repeatedly column chromatography was performed for the isolation and purification. The structures were elucidated on the basis of extensive spectral data （IR, MS, 1 D- and 2D-NMR） analysis by comparing with literature data. A new cembranoid diterpene namely sarcophyolide A （1）, together with 7a, 8β-dihydroxydeepoxysarcophine （2） were isolated from this species. The cembranoid diterpenes with 7-1actone could be chemotaxonomic markers of Sarcophyton sp.
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.
