New phospholipid fatty acids from the marine sponge Cinachyrella alloclada uliczka

The fatty acid composition of phospholipids from the Senegalese sponge Cinachyrella alloclada was examined. Two new fatty acids not hitherto found in nature, namely 10,13‐octadecadienoic acid and 16‐tricosenoic acid, were identified. 8‐Hexadecenoic, 13‐nonadecenoic and 5,9,13‐trimethyltretradecanoic fatty acids were also found for the first time in sponges. The latter compound (1.4% of the total fatty acid mixture), an isoprenoid fatty acid, accompanies the major fatty acid 4,8,12‐trimethyltridecanoic acid (19.7%). The monomethyl branched fatty acids (22%) identified include 23‐methylpentacosanoic acid (anteiso‐26∶0), not previously observed in sponged. The major long‐chain fatty acids encountered were the known 17‐tetracosenoic 19‐heptacosadienoic and 5,9,23‐tricontatrienoic acid. Some sixty fatty acids were identified as methyl esters and N ‐acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry.