高等学校化学学报

高等学校化学学报 ›› 1996, Vol. 17 ›› Issue (1): 60.

• 论文 • 上一篇    下一篇

氨基酸氧化反应的动力学研究

马克勤, 袁蔚森, 尚振锋, 赵学庄   

  1. 南开大学化学系, 天津 300071
  • 收稿日期:1995-01-18 出版日期:1996-01-24 发布日期:1996-01-24
  • 通讯作者: 赵学庄
  • 作者简介:马克肠,男,55岁,副教授.
  • 基金资助:

    国家自然科学基金

Kinetics and Mechanism of Oxidation of α-Aminino Acids by N-bromosuccinimiole

MA Ke-Qh, YUAN Wei-Sen, SHANG Zhen-Feng, ZHAO Xue-Zhuang   

  1. Department of Chemistry, Nankai University, Tianjin 300071
  • Received:1995-01-18 Online:1996-01-24 Published:1996-01-24

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摘要： 利用紫外吸收光谱法研究了α-氨基酸与N-溴代琥珀酰亚胺(NBS)进行氧化反应的动力学。结果表明:反应对NBS为一级,对α-氨基酸为正分数级,准一级反应速率常数kobs随[OH-]增加而降低,离子强度及扩散效应对反应无影响。提出了反应的可能机理,导出的速率方程圆满地解释了实验现象,并且计算出了速控步的速率常数、前期平衡常数等动力学参数。

关键词: 氨基酸, 氧化反应, 非线性拟合, 机理

Abstract: The kinetics of the oxidtive decarboxylation of amino acids promoted by-bro-mosuccinimole(NBS)has been studied hy spectrophotometry in aqueous acid and alkalinemedium.The reaction was first order in NBS, and fractional order in amino acids.It wasfound that the pseudo first-order([AA]0»[NBS]0 rate constants decreases with the in-crease of[OH-](see Fig.2), and ionic strength and diffusion have no effect on the rate con-stants. Based on the experimental results, a mechanism involving the formatin of an inter-mediate, its slow decomposition to an imine,and subsequent rapid conversion of imine toproducts is proposed and the derived rate law was in good agreement with the experimentalobservations and the preequilidrium constants, rate constant of the rate-determining step to-gether with the activation parameters were evaluated.

Key words: Amino acid, Oxidation reaction, Computer simulation, Mechanism

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