A new sesquiterpene from the Hainan gorgonian Menella kanisa Grassoff.

Chemical investigation of the gorgonian Menella kanisa Grassoff collected from the South China Sea led to the isolation of a new sesquiterpene, menecubebane A (1), together with three known compounds, 8-methoxy-trans-calamenene (2), 8,9-dihydro-linderazulene (3) and (3β)-oleanan-3-ol (4). The structure of 1 was determined by detailed analysis of the spectroscopic data especially the NOESY spectrum. All the compounds were evaluated for their cytotoxic, brine shrimp lethal and antifouling activities.