高等学校化学学报 ›› 1998, Vol. 19 ›› Issue (6): 890.

• 论文 • 上一篇    下一篇

抗坏血酸与过氧化氢反应的自旋捕捉┐ESR研究

白令君, 王建英   

  1. 南开大学化学系, 天津, 300071
  • 收稿日期:1997-05-10 出版日期:1998-06-24 发布日期:1998-06-24
  • 通讯作者: 白令君,女,56岁,教授.
  • 作者简介:白令君,女,56岁,教授.

The ESR Spin Trapping Studies of Reaction Between Ascorbic Acid with Hydrogen Peroxide

BAI Ling-Jun, WANG Jian-Ying   

  1. Department of Chemistry, Nankai University, Tianjin, 300071
  • Received:1997-05-10 Online:1998-06-24 Published:1998-06-24

摘要: 利用自旋捕捉-ESR方法研究了分析纯抗坏血酸(Aa)与医用维生素C注射液(Vc)的自氧化和过氧化氢反应,在自氧化反应中只观察到去氢抗坏血酸负离子基A,而与过氧化氢反应时除观察到A外,还观测到另外数种自由基,经计算机拟合后得到这些自由基或其5,5-二甲基-1-吡咯啉-1-氧化物(DMPO)加合物的ESR谱参数,在此基础上推测出该反应的机理.

关键词: 抗坏血酸, 自旋捕捉-ESR, 过氧化氢, 去氢抗坏血酸负离子基

Abstract: Using 5,5-dimethyl-1-pyrroline N-oxide(DMPO) as a spin-trapping reagent, the oxidation reaction of ascorbic acid was studied. The radical generated in autoxidation process was ascorbate radical anion(A) only. In the presence of hydrogen peroxide, several radical intermediates were found and their structure were determined. The ESR parameters of A and DMPO/radical adducts were measured to be g =2.0056 and α H=0.17 mT for A, g =2.0059, αN=1.60 mT and αHβ=2.28 mT for DMPO/1, g =2.0059, αN=1.58 mT, αHβ=2.13 mT and αHγ=0.17 mT for DMPO/2, g =2.0059 and αN= αHβ=1.49 mT for DMPO/·OH, and g =2.0059 and αN=1.50 mT for DMPO/3(or 4). The mechanisms for the oxidation reactions of ascorbic acid were proposed on the basis of those observation.

Key words: Ascorbic acid, ESR-spin trapping, Hydrogen peroxide, Ascorbate radical anion

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