Liu Z L, Wang L J, Liu Y C
National Laboratory of Applied Organic Chemistry, Lanzhou University, PRC.
Sci China B. 1991 Jul;34(7):787-95.
The reaction of vitamin E (alpha-tocopherol) with linoleic acid containing peroxidized linoleic acid has been studied. No significant reaction was found in ethanol solution, whereas in sodium dodecyl sulfate micelles vitamin E reacted rapidly with peroxidized linoleic acid, and thereby induced the peroxidation of linoleic acid, leading to oxygen absorption. The reaction kinetics was studied in detail by u.v. spectroscopy, HPLC and ESR spectroscopy. It was found that the main product was alpha-tocopherone with alpha-tocopheroxy radical as the reaction intermediate. A mechanism involving two consecutive bimolecular reactions between peroxidized linoleic acid and alpha-tocopherol and between peroxidized linoleic acid and alpha-tocopheroxy radical, with rate constant 2.93 and 6.21 mol/L-1s-1 respectively is proposed. The micellar effect on the reaction is discussed.
对维生素E(α-生育酚)与含有过氧化亚油酸的亚油酸之间的反应进行了研究。在乙醇溶液中未发现明显反应,而在十二烷基硫酸钠胶束中,维生素E与过氧化亚油酸迅速反应,从而引发亚油酸的过氧化反应,导致吸氧。通过紫外光谱、高效液相色谱和电子自旋共振光谱对反应动力学进行了详细研究。结果发现主要产物是α-生育醌,α-生育酚氧基自由基为反应中间体。提出了一种机制,涉及过氧化亚油酸与α-生育酚之间以及过氧化亚油酸与α-生育酚氧基自由基之间的两个连续双分子反应,速率常数分别为2.93和6.21 mol/L-1s-1。讨论了胶束对反应的影响。