Puppione D L, Kuehlthau C M, Jandacek R J, Costa D P
Long Marine Laboratory, University of California, Santa Cruz 95064.
Lipids. 1992 Aug;27(8):637-9. doi: 10.1007/BF02536124.
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.
已确定南极毛皮海狮（Arctocephalus gazella）乳三酰甘油中脂肪酸的位置分布。特别令人感兴趣的是乳三酰甘油（TG）中多不饱和n-3脂肪酸的位置分布。在鳍足类动物的脂肪细胞中，TG合成时n-3脂肪酸主要位于sn-1,3位。为确定位置分布，酶解脂质提取物通过薄层色谱法分离，组成脂肪酸通过气液色谱法分离并定量。单烯酸和饱和脂肪酸占总量的75%以上，单烯酸与饱和脂肪酸的比例为2:1。长链n-3脂肪酸20:5、22:5和22:6的含量百分比在15%-20%之间。位置分析表明，在乳TG的sn-2位，饱和脂肪酸过量（57%），n-3脂肪酸含量低于5%。乳中80%以上的n-3脂肪酸位于sn-1,3位。数据表明，在鳍足类动物中，TG在乳腺和脂肪组织中合成时脂肪酸具有相似的位置分布。
