UNCOMMON 16 1 (N-5) ACID FROM DICTYOTA-DICHOTOMA AND FATTY-ACIDS OF SOME BROWN-ALGAE OF DICTYOTACEAE/

The detailed fatty acid composition of the brown algae, Dictyota dicho toma, Dictyopteris divaricata and Dicryota cervicornis are reported. A bout 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 fat ty acids in minute amounts are characteristic features of algae from t he 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 dichoto ma are reported. The 16:1(n-5) acid was identified in glycolipids and betaine lipid.