α-羟乙基过氧自由基的自身衰变及其与槲皮素和邻苯二酚反应的脉冲辐解动力学研究

Pulse Radiolysis Kinetic Studies of the Self Decay of α-Hydroxyl Ethyl Peroxyl Radicals and Their Reactions with Quercetin and Pyrocatechol

脂质过氧化反应是人体内很多病理现象的原因 ,而槲皮素是一种很强的过氧化反应抑制剂 .本文选择α-羟乙基过氧自由基作为脂质过氧自由基的模拟物 ,研究了其与槲皮素和邻苯二酚的反应动力学 .首次得到纯乙醇体系中 α-羟乙基自由基的一级和二级自身衰变速率常数分别为 (4 0 .4± 2 .6) s- 1和 (6.9± 0 .9)×1 0 8mol- 1·L· s- 1 .用脉冲辐解方法得到槲皮素与 α-羟乙基过氧自由基反应的速率常数为 (2 .1± 0 .3 )× 1 0 7mol- 1·L· s- 1 .同时选择邻苯二酚作为多酚化合物的模型化合物 ,用脉冲辐解法研究了其与 α-羟乙基过氧自由基的反应 .得到邻苯二酚与α-羟乙基过氧自由基反应的速率常数为 (3 .1± 0 .1 )× 1 0 5mol- 1 · L·

Lipid Peroxidation(LPO) plays an important role in many pathological processes, while quercetin is an effective LPO inhibitor. \%α\%\|Hydroxyl ethyl peroxyl radical was chosen to act as a model of lipid peroxyl radical in the kinetic studies of its reaction with quercetin and pyrocatechol. The 1st and 2nd order decay rates of \%α\%\|hydroxyl ethyl peroxyl radical in ethanol solution were obtained for the first time to be (40.4±2.6) s\+\{-1\} and (6.9±0.9)×10\+8\{mol\+\{-1\}\5L\5s\+\{-1\}\}, respectively. The rate constant of the reaction between \%α\%\|hydroxyl ethyl peroxyl radical and quercetin was determined to be (2.1±0.3)×10\+7 \{mol\+\{-1\}\5L\5s\+\{-1\}\} through pulse radiolysis studies. Pyrocatechol was chosen to act as a model compound of polyphenols and its reaction with \%α\%\|hydroxyl ethyl peroxyl radical was studied. The rate constant of the reaction between \%α\%\|hydroxyl ethyl peroxyl radical and pyrocatechol was determined to be (3.1±0.1)×10\+5 \{mol\+\{-1\}\5L\5s\+\{-1\}\}.