Kinetics and Catalysis Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416004, India.
Amino Acids. 2010 Mar;38(3):789-95. doi: 10.1007/s00726-009-0285-0. Epub 2009 Apr 15.
The reaction between methionine and enneamolybdomanganate(IV) in perchloric acid was carried out under pseudo-first-order conditions keeping large excess of methionine. The orders in oxidant and substrate were found to be unity and 0.91, respectively. The reaction proceeds with rapid formation of complex between the reactants followed by its decomposition in a rate determining step. The accelerating effect of hydrogen ions on the reaction is due to the formation of active hexaprotonated oxidant species. The product of the reaction was found to be methionine sulfoxide. The reaction involves direct two-electron transfer step without any free radical intervention. The effect of ionic strength, solvent polarity and the activation parameters were also in support of the mechanism proposed.
蛋氨酸与高铼酸在高氯酸中的反应是在保持大量过量蛋氨酸的条件下进行的。发现氧化剂和底物的级数分别为 1 和 0.91。反应迅速形成反应物之间的配合物，然后在速控步骤中分解。氢离子对反应的加速作用是由于活性六质子化氧化剂物种的形成。反应产物被发现为蛋氨酸亚砜。反应涉及直接的两电子转移步骤，没有任何自由基干预。离子强度、溶剂极性和活化参数的影响也支持所提出的机制。
