Identification of a new 6-bromo-5,9-eicosadienoic acid from the anemone condylactis gigantea and the zoanthid palythoa caribaeorum

A new brominated fatty acid, 6-bromo-5,9-eicosadienoic acid [1] was identified in the phospholipids (mainly phosphatidylethanolamine) of the anemone Condylactis gigantea and the zoanthid Palythoa caribaeorum. The Δ^5,9 fatty acids, 5,9-octadecadienoic acid, 5,9-eicosadienoic acid, 5,9-docosadienoic acid, and 5,9-tetracosadienoic acid, were also identified in both organisms. Structural elucidation was accomplished by spectroscopic and chemical mean. Our results further corroborate that Δ^5,9 phospholipid fatty acids are not unique to sponges, as recognized previously, but can be found in other marine invertebrates such as anemones and zoanthids. An improved procedure for the synthesis of picolinyl esters is also described.