title: Positional analyses of triacylglycerol fatty acids in the milk fat of the antarctic fur seal (Arctocephalus gazella).
abstract: The positional distribution of fatty acids has been determined for the milk triacylglycerols of the Antarctic fur seal, Arctocephalus gazella. Of particular interest was the positional distribution of the polyunsaturated n-3 fatty acids in milk triacylglycerols (TG). In adipocytes of pinnipeds, TG are synthesized with the n-3 fatty acids primarily in the sn-1,3 positions. To determine the positional distribution, extracts of enzymatically digested lipids were separated by thin-layer chromatography, and the constituent fatty acids were separated and quantified by gas-liquid chromatography. Monoenoic and saturated fatty acids comprised over 75% of the total, the ratio of monoenoic to saturated fatty acids being 2:1. The percent content of the long-chain n-3 fatty acids, 20:5, 22:5 and 22:6, ranged between 15-20%. The positional analyses revealed that at the sn-2 position of milk TG, saturated fatty acids were in excess (57%), and the content of n-3 fatty acids was less than 5%. More than 80% of the n-3 fatty acids in milk were located in the sn-1,3 positions. The data indicate that in pinnipeds TG are synthesized in the mammary gland and adipose tissue with fatty acids having similar positional distributions.
authors.affiliation: Long Marine Laboratory, University of California, Santa Cruz 95064.
authors.forename: D L
authors.initials: DL
authors.lastname: Puppione
authors.forename: C M
authors.initials: CM
authors.lastname: Kuehlthau
authors.forename: R J
authors.initials: RJ
authors.lastname: Jandacek
authors.forename: D P
authors.initials: DP
authors.lastname: Costa
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D005260:Female; D046069:Fur Seals; D008321:Mammary Glands, Animal / Q000378:metabolism; D008892:Milk / Q000737:chemistry*; D014280:Triglycerides / Q000032:analysis* / Q000096:biosynthesis
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D014280:Triglycerides