Abstract
The distribution of docosahexaenoic (22:6n-3; DHA) and icosapentaenoic (20:5n-3; EPA) acids in phosphatidylcholine (PC) and/or phosphatidylethanolamine (PE) from different tissues of two species of squids, spear squid Loligo bleekeri and Pacific flying squid Todarodes pacificus, was studied. Mantles, fins, arms, and integuments of squid and liver of the former species contained small amounts of lipid (TL: 1.8-4.3% of wet weight) comprised almost entirely of PC (47.9-67.0%), sterols (14.2-32.7%), and PE (12.2-15.7%). Liver of the latter species contained copious amounts of TL (36.2%) with higher triacylglycerols (97.0%). In PC and PE from squid tissue, DHA (24.7-37.6% for PC and 7.4-25.0% for PE), EPA (6.3-18.4% and 18.9-38.8%, respectively) and palmitic acid (28.6-44.0% and 11.0-22.5%, respectively) were characteristically present. In squid tissue, except the liver, component fatty acids at sn-position 2 of PC and PE were polyunsaturated for the most part with the predominant component of DHA (71.3-78.7% for PC and 17.1-45.3% for PE) and EPA (10.9-14.4% and 37.2-58.0%, respectively). These acids at sn-position 1 of PC and PE were more saturated with palmitic (66.4-72.9% for PC and 15.9-41.6% for PE) and stearic (4.2-6.9% and 9.8-30.0%, respectively) acids. LysoPC, enriched with DHA (66.1%) and EPA (11.1%), was obtained from squid tissue PC (DHA: 36.4%, EPA: 6.7%) by Lipase M10 hydrolysis.
