On the isolation of the new fatty acid 6,11-eicosadienoic (20:2) and related 6,11-dienoic acids from the sponge Euryspongia rosea.

The phospholipid fatty acids from the sponge Euryspongia rosea were studied revealing the presence of the new 6,11-eicosadienoic (20:2) acid and the rare 6,11-octadecadienoic acid (18:2). The isolation of these 6,11-dienoic acids reveals the presence of new biosynthetic possibilities in sponges and suggests the presence of an active delta 6 desaturase in E. rosea. Other acids isolated from E. rosea include 12-eicosenoic (20:1) and 17-tetracosenoic acid (24:1). The major phospholipids encountered in the sponge were phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylcholine (PC).