Simplexolides A-E and plakorfuran A, six butyrate derived polyketides from the marine sponge .

Six new polyketides, simplexolides A-E () and a furan ester, plakorfuran A (), together with four known furanylidenic methyl esters () were isolated from the marine sponge . Compounds feature a tetrahydrofuran ring opened skeleton. These new structures, including relative configurations, were determined on the basis of extensive analysis of spectroscopic data. The absolute configurations of were established by the modified Mosher's method, and the CD exciton chirality method. However, configurations of the remote stereocenters at C-8 in compounds were not determined. Antifungal, cytotoxicity, antileismanial, and antimalarial activities of these poly-ketides were evaluated.