Non-methylene-interrupted and omega4 dienoic fatty acids of the white shrimp Penaeus setiferus.

The total lipid fatty acids from the white shrimp Penaeus setiferus were found to contain several unusual dienoic fatty acid species. These included two methylene-interrupted species: delta 11, 14-C18:2 (18:2omega 4) and delta 13, 16-C20:2 (20:2omega4). Also found were several non-menthylene-interrupted dienoic fatty acids including delta 7, 11 and delta 7, 13-C20:2, delta 7, 13-C21:2, delta 7, 13, delta 7, 15, delta 9, 13, delta 9, 15,, and delta 7, 17-C22:2. Many minor C20:2 non-mentylene-interrupted dienes were found but could not be unequivocally characterized.