A new furanosesterpene from the marine sponge Psammocinia rugosa
A tetronic acid (5), 5-[13-(furan-3-yl)-2,6,10-trimethyltrideca-2,6,8-trienyl]-4-hydroxy 3-methylfuran-2(5H)-one,* with weak antimicrobial activity has been isolated from the sponge Psammocinia sp. and characterized by analysis of 1H and 13C n.m.r. data including 'H-1H correlation (COSY) experiments. The compound may be identical to a tetronic acid isolated by the Roche group, previously assigned structure (3).