Novel brominated phospholipid fatty acids from the Caribbean sponge Agelas sp.

The very long-chain fatty acids, (5E,9Z)-6-bromo-5,9-tetracosadienoic, (5E,9Z)-6-bromo-23-methyl-5,9-tetracosadienoic, (5E,9Z)-6-bromo-5,9-pentacosadienoic and (5E,9Z)-6-bromo-24-methyl-5,9- pentacosadienoic acids, were identified in the phospholipids (mainly phosphatidylethanolamine) of the sponge Agelas sp. Structure elucidation was accomplished by means of mass spectrometry and chemical transformations, including deuteration with Wilkinson's catalyst. All of the sterols from the sponge had the delta 5,7 nucleus, with 24-methylcholesta-5,7,22-trien-3 beta-ol (ergosterol) and 24-ethyl-cholesta-5,7, 22-trien-3 beta-ol being the most abundant.