Granulatosides D, E and other polar steroid compounds from the starfish Choriaster granulatus . Their immunomodulatory activity and cytotoxicity.

Two new steroid glycosides, granulatosides D ( 1 ) and E ( 2 ), belonging to the group of bi- and monoglycosides of polyhydroxysteroids, respectively, were isolated from the ethanolic extract of the starfish Choriaster granulatus along with thirteen previously known glycosides of polyhydroxysteroids ( 3 - 15 ) and one steroid heptaol ( 16 ). The structures of the new compounds were elucidated by extensive NMR and ESIMS techniques. Cytotoxic and immunomodulatory activities of compounds 1 , 3 - 8 , and 10 - 16 using murine splenocytes and peritoneal macrophages were studied. At a dose of 0.1 μM new glycoside 1 showed immunomodulatory properties, increasing the intracellular ROS (reactive oxygen species) level in peritoneal murine macrophages by 20% and decreasing intracellular ROS level by 21% in pre-treated with endotoxic lipopolysaccharide from E. coli (LPS) peritoneal macrophages.