Akesson B, Gronowitz S, Herslof B, Ohlson R
Lipids. 1978 May;13(5):338-43. doi: 10.1007/BF02533725.
The stereochemistry of fat digestion and absorption was investigated in rats with thoracic duct fistulas, after feeding synthetic triacylglycerol or alkyldiacylglycerol. After feeding 1,2-dilauroyl-3-oleoyl-sn-glycerol, dilauroyloleoylglycerol and lauroyldioleoylglycerol were the most abundant chyle triacylglycerols. Positional analysis of the fatty acid distribution and the absence of optical activity indicated that the following structures dominated: rac-1,2-dilauroyl-3-oleoylglycerol and rac-1,3-dioleoyl-2-lauroylglycerol. Therefore, the triacylglycerol resynthesized from 2-lauroylglycerol (pre-cursor to 60% of chyle triacylglycerol) and other precursors was essentially racemic. Chyle phospholipids contained largely endogenous fatty acids, and the proportion of lauric acid was very low. A racemic mixture of 1,2-di[3H] oleoyl-3-tetradecyl-sn-glycerol and 1-tetradecyl-2,3-di[12C] oleoyl-sn-glycerol was absorbed to a lower degree than triacylglycerol. The appearace of oleic acid with different labels in chyle and intestinal lipids did not differ, indicating the absence of stereospecificity in fat digestion. Possible explanations for the low absorption are discussed.
在给患有胸导管瘘管的大鼠喂食合成三酰甘油或烷基二酰甘油后，对脂肪消化和吸收的立体化学进行了研究。喂食1,2 - 二月桂酰 - 3 - 油酰 - sn - 甘油后，二月桂酰油酰甘油和月桂酰二油酰甘油是最丰富的乳糜三酰甘油。脂肪酸分布的位置分析以及旋光性的缺乏表明以下结构占主导：外消旋1,2 - 二月桂酰 - 3 - 油酰甘油和外消旋1,3 - 二油酰 - 2 - 月桂酰甘油。因此，由2 - 月桂酰甘油（占乳糜三酰甘油的60%的前体）和其他前体重新合成的三酰甘油基本上是外消旋的。乳糜磷脂主要含有内源性脂肪酸，月桂酸的比例非常低。1,2 - 二[3H]油酰 - 3 - 十四烷基 - sn - 甘油和1 - 十四烷基 - 2,3 - 二[12C]油酰 - sn - 甘油的外消旋混合物的吸收程度低于三酰甘油。乳糜和肠道脂质中不同标记油酸的出现情况没有差异，表明脂肪消化中不存在立体特异性。讨论了吸收低的可能原因。
