Frankel E N, Neff W E, Selke E, Weisleder D
Nothern Regional Research Center, Agricultural Research, U.S. Department of Agriculture, 61604, Peoria, IL.
Lipids. 1982 Jan;17(1):11-8. doi: 10.1007/BF02535116.
Studies of photosensitized oxidation of methyl linoleate show that the greater relative concentration of 9- and 13-hydroperoxides than 10- and 12-hydroperoxides is characteristic of singlet oxygenation and not due to either simultaneous autoxidation or type 1 photosensitized oxidation. Cyclization of the internal 10- and 12-hydroperoxides accounts for their lower relative concentrations. Secondary products separated by silicic acid and high pressure liquid chromatography were characterized spectrally (IR, UV,(1)H-NMR,(13)C-NMR, GC-MS). Major secondary products included diastereomeric pairs of 13-hydroperoxy-10,12-epidioxy-trans-8-octadecenote (I and III) and 9-hydroperoxy-10,12-epidioxy-trans-13-octadecenoate (II and IV); minor secondary products included hydroperoxy oxy genated and epoxy esters. Thermal decomposition of the hydroperoxy cyclic peroxides produced hexanal and methyl 10-oxo-8-decenoate as major volatiles from I and III and methyl 9-oxo-nonanoate and 2-heptenal from II and IV. Hydroperoxy cyclic peroxides may be important sources of volatile decomposition products of photooxidized fats.
亚油酸甲酯的光敏氧化研究表明，相对于10 - 氢过氧化物和12 - 氢过氧化物，9 - 氢过氧化物和13 - 氢过氧化物的相对浓度更高是单线态氧氧化的特征，并非同时发生的自动氧化或I型光敏氧化所致。内部的10 - 氢过氧化物和12 - 氢过氧化物的环化导致了它们相对浓度较低。通过硅酸和高压液相色谱分离得到的二级产物用光谱法（红外光谱、紫外光谱、¹H - 核磁共振、¹³C - 核磁共振、气相色谱 - 质谱联用）进行了表征。主要二级产物包括非对映异构体对13 - 氢过氧基 - 10,12 - 环氧氧基 - 反式 - 8 - 十八碳烯酸酯（I和III）以及9 - 氢过氧基 - 10,12 - 环氧氧基 - 反式 - 13 - 十八碳烯酸酯（II和IV）；次要二级产物包括氢过氧基氧化酯和环氧酯。氢过氧基环状过氧化物的热分解产生己醛和10 - 氧代 - 8 - 癸烯酸甲酯作为I和III的主要挥发性产物，以及9 - 氧代壬酸甲酯和2 - 庚烯醛作为II和IV的主要挥发性产物。氢过氧基环状过氧化物可能是光氧化脂肪挥发性分解产物的重要来源。
