New Steroid Glycosides from the Deep-Water Starfish Mediaster murrayi

Four new 24-O-biosides of 5alpha-cholestane-3beta,6alpha,8,15beta, 24-pentaol, designated as mediasterosides M1 (1), M2 (2), M3 (3), and M4 (4), and the previously known 5alpha-cholestane-3beta,6beta,8, 15alpha,16beta,26-hexaol (5) have been isolated from the deep-water starfish Mediaster murrayi. Glycosides 1-3 contain rare carbohydrate moieties with (1-->5) bonds between the monosaccharide units. Compounds 1 and 2 showed the inhibition of cell division of fertilized sea urchin eggs and exhibited moderate hemolytic activities.