Polyhydroxy Sterols Isolated from the Red Sea Soft Coral Lobophytum crassum and their Cytotoxic Activity

摘要

One new (1) together with four known sterols (2-5) and a sesquiterpene (6) were isolated from a polar extract of the Red Sea soft coral Lobophytum crassum. The compounds were identified as 24-methylenecholest-5-ene-1 alpha,3 beta,11 alpha-triol 1-acetate (1), 24-methylenecholest-5-ene-1a,3 beta(,)11 alpha-triol (2), 24-methylenecholest-5-ene-3 beta-ol (3), 24-methylenecholestane-1 alpha,3 beta,5 alpha,6 beta,11 alpha-pentol (4), 24-methylenecholestane-3 beta,5 alpha,6 beta-triol (5) and alismoxide (6) based on extensive NMR analysis. The cytotoxicity of compounds 1-6 was evaluated in vitro using three human cancer cell lines viz., HepG2, Hep-2 and HCT-116. Compound 1 showed selective cytotoxic activity against HepG2, while 3 exhibited cytotoxicity against all tested cell lines.