Uncommon 16:1 (n-5) acid from Dictyota dichotoma and fatty acids of some brown algae of dictyotaceae

Abstract The detailed fatty acid composition of the brown algae, Dictyota dichotoma, Dictyopteris divaricata and Dictyota cervicornis are reported. About 35 fatty acids were identified, of which 16:0, 18:4 (n-3), 18:1(n-9), 14:0 and 20:4(n-6) predominated in each sample. A high content of an uncommon 16:1(n-5) and the occurrence of C 22 polyunsaturated fatty acids in minute amounts are characteristic features of algae from the genus Dictyota and Dictyopteris divaricata . The structure of 16:1(n-5) was confirmed by GC and mass spectrometry of its derivatives. The distribution of fatty acids among the polar lipids of Dictyota dichotoma are reported. The 16:1(n-5) acid was identified in glycolipids and betaine lipid.