Phospholipids in Mediterranean cephalopods.

Polar lipids of the cephalopods Eledone moschata, Sepia officinalis and Todarodes sagittatus mantle, represent 50.5%, 66.1% and 74.2% of wet tissue respectively. On the other hand the polar lipids of these three species of cephalopods constitute of 80.8%, 94.8% and 93.7% of phospholipids, respectively. The main phospholipids identified were phosphatidylcholine (52.2, 51.3 and 58.4% of total phospholipids respectively in the above mentioned species), phosphatidylethanolamine (18.1, 19.7 and 23.9%), sphingomyelin (10.7, 15.2 and 6.7%), lyso-phosphatidylcholine (3.1, 3.8 and 1.8%) and the unusual lipid ceramide aminoethylphosphonic acid (15.9, 10 and 9.2%). The 56.8% of phosphatidylcholine in Eledone moschata, the 46% in Sepia officinalis and the 74.1% in Todarodes sagittatus refer to the structure of 1,2-diacyl-glycerocholine and the remaining percentage refer to the structure of 1-o-alkyl-2-acyl-glycerocholine or 1-o-alkyl-1-enyl-2-acyl-glycerocholine. The 87.2% of phosphatidylethanolamine in Eledone moschata, the 81% in Sepia officinalis and the 90.7% in Todarodes sagittatus refer to the structure of 1,2-diacyl-glyceroethanolamine and the remaining percentage refer to the structure of 1-o-alkyl-2-acyl-glyceroethanolamine or 1-o-alkyl-1-enyl-2-acyl-glyceroethanolamine. The major saturated fatty acids in phosphatidylcholine and phosphatidylethanolamine were C16:0 (30.3-67.5% and 23.2-54.5%) and C18:0 (3.6-17% and 15.4-28%), respectively, while the major unsaturated fatty acids in these lipids were C18:1n-9, n-7 (1.0-7.3% and 5.3-10.5%), C20:5n-3 (1.5-9.8% and 4,5-15.8%) and C22:6n-3 (12.5-42.0% and 7.0-11.3%), respectively.