Antigenotoxic ketosteroid from the red algae Jania adhaerens

A new ketosteroid, 6 beta,16 beta -dihydroxycholest-4-en-3-one (1), in addition to the known 6 beta-hydroxycholest-4-en-3-one (2), 6 beta-hydroxycholest-4, 22-dien-3-one (3) and 16 beta-hydroxy-5 alpha-cholestan-3,6-dione (4), was isolated from the red alga Jania adhaerens. The structures were assigned on the basis of H-1-and C-13-NMR experiments. The new compound (1) was evaluated for its genotoxic and cytotoxic activities and found to possess protective antigenotoxicity in human peripheral blood cells.