Kinetics and mechanism of the oxidation of DL-methionine by quinolinium fluorochromate

摘要

The oxidation of methionine(Met)by quinolinium fluorochromate(QFC)in dimethylsulphoxide(DMSO)leads to the formation of corresponding sulphoxide.The reaction is of first order with respect to QFC.Michaelis-Mcnten type kinetics was observed with respect to methionine.The reaction is catalysed by hydrogen ions.The hydrogen-ion dependence has the form:k_obs=a + b[H~+].The oxidation of methionine was studied in nineteen different organic solvents.The solvent effect was analyzed by Kamlet's and Swain's multiparametric equations.Solvent effect indicated the importance of the cation-solvating power of the solvent.A suitable mechanism has also been postulated.