Ethyl esters and phosphatidylcholines (PCs) of polyunsaturated fatty acids (PUFAs) were oxidized in organic solvents, aqueous emulsions, and liposomes in the presence of a radical inducer. Oxidation products and the positional distribution of monohydroperoxide (MHP) were determined by gas chromatography-mass spectrometry (GC-MS) analysis. The total amount of the oxidation products, of PUFA ethyl esters and PCs in organic solvents, increased with an increase in the number of bis-allylic positions. However, the opposite results were obtained in an aqueous emulsion and liposomes. The distribution pattern of MHPs obtained from oxidation of the linolate and alpha-linolenate showed little difference between a chloroform solution and an aqueous emulsion or liposomes. However, there were differences between these systems with the arachidonate, the icosapentaenoate, and docosahexaenoate. These results may be due to the different rate of hydrogen abstraction from bis-allylic positions in the fatty acid moieties, and/or 1,3-cyclization of hydroperoxides in the systems.

中文翻译：

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水性和有机体系中脂质氧化产物成分的比较研究。

在自由基诱导剂的存在下，多不饱和脂肪酸（PUFA）的乙酯和磷脂酰胆碱（PCs）在有机溶剂，水性乳液和脂质体内被氧化。通过气相色谱-质谱（GC-MS）分析确定氧化产物和一氧化二氢（MHP）的位置分布。随着双烯丙基位置数量的增加，有机溶剂中PUFA乙酯和PCs的氧化产物总量增加。然而，在水性乳液和脂质体中获得相反的结果。由亚麻酸酯和α-亚油酸酯的氧化获得的MHP的分布模式在氯仿溶液和水乳液或脂质体之间显示出很小的差异。但是，花生四烯酸在这些系统之间存在差异，二十碳五烯酸酯和二十二碳六烯酸酯。这些结果可能是由于脂肪酸部分中双烯丙基位置的氢提取速率不同和/或系统中氢过氧化物的1,3-环化作用。