Mechanistic aspects of oxidation on L-tyrosine by diperiodatocuprate(III) complex in alkali media: a kinetic model

被引：4

作者：

Shetti, Nagaraj P. ^{[1
]}

Hegde, Rajesh N. ^{[1
]}

Nandibewoor, Sharanappa. T. ^{[1
]}

机构：

[1] Karnatak Univ, PG Dept Studies Chem, Dharwad 580003, Karnataka, India

来源：

CENTRAL EUROPEAN JOURNAL OF CHEMISTRY | 2009年 / 7卷 / 04期

关键词：

Kinetics; Mechanism; L-tyrosine; Diperiodatocuprate(III); L-VALINE; ELECTRON; ACID;

D O I：

10.2478/s11532-009-0085-0

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Oxidation of an amino acid, L-tyrosine (L-Tyr) by diperiodatocuprate(III) (DPC) in alkaline medium at a constant ionic strength of 0.1 mol dm(-3) was studied spectrophotometrically at different temperatures (288.1-313.1 K). The reaction between DPC and L-Tyr in alkaline medium exhibits 1:4 stoichiometry (L-Tyr:DPC). Intervention of free radicals was observed in the reaction. Based on the observed orders and experimental evidence, a mechanism involving monoperiodatocuprate(III) (MPC) as the reactive oxidant species has been proposed. A suitable mechanism is proposed through the formation of a complex and free radical intermediate. The products were identified by spot test and characterized by spectral studies. The reaction constants involved in the different steps of the mechanism were calculated. The activation parameters with respect to slow step of the mechanism were computed and are discussed. The thermodynamic quantities were determined for different equilibrium steps. Isokinetic temperature was also calculated and found to be 252.3 K.

引用

页码：929 / 937

页数：9