物理化学学报 >> 2012, Vol. 28 >> Issue (01): 213-216.doi: 10.3866/PKU.WHXB201228213

光化学和辐射化学 上一篇    下一篇

维生素K3的激发三重态与色氨酸、酪氨酸电子转移氧化反应的激光闪光光解研究

唐睿智1,2, 李海霞1,2, 刘艳成1,2, 张鹏1,2, 曹西艳1,3, 王文锋1   

  1. 1. 中国科学院上海应用物理研究所, 上海 201800;
    2. 中国科学院研究生院, 北京 100049;
    3. 湖南科技大学化学化工学院, 湖南湘潭 411201
  • 收稿日期:2011-09-07 修回日期:2011-10-25 发布日期:2011-12-29
  • 通讯作者: 王文锋 E-mail:wangwenfeng@sinap.ac.cn
  • 基金资助:

    国家自然科学基金(21173252)资助项目

Laser Flash Photolysis Study on Electron Transfer Oxidation Reaction of Tryptophan or Tyrosine with Triplet State Vitamin K3

TANG Rui-Zhi1,2, LI Hai-Xia1,2, LIU Yan-Cheng1,2, ZHANG Peng1,2, CAO Xi-Yan1,3, WANG Wen-Feng1   

  1. 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China;
    2. Graduate University of Chinese Academy of Sciences, Beijing 100049, P. R. China;
    3. School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan Province, P. R. China
  • Received:2011-09-07 Revised:2011-10-25 Published:2011-12-29
  • Contact: WANG Wen-Feng E-mail:wangwenfeng@sinap.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173252).

摘要: 利用时间分辨的激光闪光光解技术研究了乙腈-水混合溶液(1:1, V/V)中2-甲基萘醌(通常称为维生素K3)的激发三重态对色氨酸、酪氨酸的光敏氧化机理. 通过瞬态吸收光谱的变化可以推断维生素K3的激发三重态可以与色氨酸、酪氨酸发生电子转移反应, 反应形成的维生素K3阴离子自由基的吸收峰可以直接从瞬态吸收谱图中观察到. 维生素K3与色氨酸、酪氨酸的电子转移反应的速率分别为1.1×109和0.6×109 L·mol-1·s-1. 吉布斯自由能(ΔG)的计算结果表明维生素K3的激发三重态与色氨酸、酪氨酸电子转移反应在热力学上是可行的.

关键词: 维生素K3, 色氨酸, 酪氨酸, 激光闪光光解

Abstract: Laser flash photolysis was used to study the photosensitized oxidation mechanism of vitamin K3, commonly known as 2-methyl-1,4-naphthoquinone (MQ), with tryptophan (TrpH) or tyrosine (TyrOH) in acetonitrile/water (1:1, V/V) solution. The triplet state of MQ reacted with TrpH or TyrOH by electron transfer with the formation of a MQ anion radical, which was directly observed in the transient absorption spectrum. The rate constants of the electron transfer reactions were determined to be 1.1×109 and 0.6×109 L·mol-1·s-1 for TrpH and TyrOH, respectively. The free energy changes (ΔG) of the reactions showed that the proposed electron transfer steps are thermodynamically feasible.

Key words: Vitamin K3, Tryptophan, Tyrosine, Laser flash photolysis

MSC2000: 

  • O644