Chemical investigation of the Antarctic sponge Dendrilla membranosa collected from the vicinity of Palmer Station on Anvers Island, Antarctica, yielded three new diterpenes, membranolides B-D (2-4), as well as three previously reported sponge metabolites. Membranolides C and D (3, 4), bearing carboxylic acid functional groups, display Gram-negative antibiotic and antifungal activities.
