Cosgrove J P, Church D F, Pryor W A
Lipids. 1987 May;22(5):299-304. doi: 10.1007/BF02533996.
The kinetics of the autoxidation of a series of polyunsaturated fatty acids (PUFA) with increasing degrees of unsaturation and the mono-, di- and triglycerides of linoleate have been studied in homogeneous chlorobenzene solution at 37 C under 760 torr of oxygen. The autoxidations were initiated by thermal decomposition of azo initiators and followed by measuring the rate of oxygen uptake. The rate of chain initiation was determined by the induction period method using alpha-tocopherol as the chain-breaking antioxidant. The measured oxidizabilities of the PUFA are linearly dependent on the number of doubly allylic positions present in the molecule. Thus, the oxidizability of linoleate is 2.03 X 10(-2) M-1/2 sec-1/2, and the value for docosahexaenoate is five times greater, 10.15 X 10(-2) M-1/2 sec-1/2. The rate of autoxidation for all PUFA studied and for the mono- and diglyceride is proportional to the substrate concentration and to the square root of the rate of chain initiation, implying that the autoxidation of these compounds follows the usual kinetic rate law. The autoxidation of the triglyceride is more complex and does not appear to follow the same rate law at all substrate concentrations. This deviation from the usual kinetic rate expression may be due to lipid aggregation at low concentrations of the triglyceride.
在37℃、760托氧气压力下，于均相氯苯溶液中研究了一系列不饱和程度不断增加的多不饱和脂肪酸（PUFA）以及亚油酸甘油一酯、甘油二酯和甘油三酯的自动氧化动力学。自动氧化由偶氮引发剂的热分解引发，通过测量氧气吸收速率进行跟踪。链引发速率通过使用α-生育酚作为断链抗氧化剂的诱导期法测定。所测得的PUFA氧化能力与分子中存在的双烯丙基位置数量呈线性相关。因此，亚油酸酯的氧化能力为2.03×10⁻² M⁻¹/² sec⁻¹/²，而二十二碳六烯酸酯的值则大五倍，为10.15×10⁻² M⁻¹/² sec⁻¹/²。所有研究的PUFA以及甘油一酯和甘油二酯的自动氧化速率与底物浓度和链引发速率的平方根成正比，这意味着这些化合物的自动氧化遵循通常的动力学速率定律。甘油三酯的自动氧化更为复杂，在所有底物浓度下似乎都不遵循相同的速率定律。这种与通常动力学速率表达式的偏差可能是由于低浓度甘油三酯时的脂质聚集所致。
