BROMINATED ACETYLENIC FATTY-ACIDS FROM XESTOSPONGIA SP, A MARINE SPONGE-BACTERIA ASSOCIATION

Three new brominated fatty acids, (5E, 11E, 15E, 19E)-20-bromoeicosa-5 , 11, 15, 19-tetraene-9, 17-diynoic acid (1), (5Z, 11E, 15E, 19E)-6, 2 0-dibromoeicosa-5, 11, 15, 19-tetraene-9, 17-diynoic acid (2) and (Z E )-14, 14-dibromo-4, 6, 13-tetradecatrienoate, characterized as the met hyl ester, 3, were isolated from Xestospongia sp. from the Indian Ocea n. Compounds 1 -2 (C-20) and 3 (C-14) are brominated fatty acids of un usual carbon number that have not been encountered previously in marin e invertebrates. Xestospongia sp. is an association of sponge cells an d bacteria, the latter accounting for ca. 50% of cellular mass.