A NEW LOBANE DITERPENE ACID FROM THE SOFT CORAL LOBOPHYTUM-MICROLOBULATUM OF THE ANDAMAN-AND-NICOBAR ISLANDS

The isolation of a new lobane diterpene acid, 13-hydroxyloba-8,10,15(E ),17(E)-tetraen-19-oic acid (2), in addition to the norsesquiterpenoid , 15-nor-13-keto-beta-elemene (1) and three steroid glycosides, namely 24-methylenecholest-5-ene-3 beta,16 beta-diol-3-O-alpha-L-fucopyranos ide (5), 24-methylene-cholest-5-ene-3 beta 7 beta, 16 beta-triol-3-O-a lpha-L-fucopyranoside (6) and 24-methylenecholest-5-ene-3 beta,7 alpha ,16 beta-triol-3-O-alpha-L-fucopyranoside (7) has been reported from t he ethyl acetate extract of the soft coral Lobophytum microlobulatum o f the Andaman and Nicobar Islands. Structure elucidation of these comp ounds is based on their spectral (UV, IR, H-1 NMR, C-13 NMR and mass) data.