Interaction between Glutathione and Resveratrol in the Presence of Hydrogen Peroxide: A Kinetic Model

Abstract

The kinetics of interaction between glutathione (GSH) and unsaturated phenol resveratrol (RVT) in deionized water in the presence of hydrogen peroxide (H2O2) is studied. At a physiological concentration (0.1–10 mM), GSH containing two carboxyl groups forms acidic solutions (pH of 3–4); the GSH molecules are associated into dimers. Under these conditions, GSH is quite slowly oxidized by atmospheric oxygen, and the reaction between GSH and H2O2 is accompanied by the formation of radicals. The thiyl radical initiation rate (Wi) is a few fractions of a percent of the GSH consumption rate; however, it is sufficient to initiate a thiol–ene chain reaction between GSH and RVT. Using the experimental data on the kinetics and the product composition and the published data on reactions of GSH with H2O2 and thiyl radicals, a kinetic model of the complex interaction between GSH and RVT in the presence of H2O2 in an aqueous medium at 37°C is proposed. The model includes 19 quasi-elementary reactions with respective rate constants, in particular, the formation of intermediate GSH–H2O2 and GSH–GSH complexes, the formation of radicals, and their subsequent transformations into final products in reactions with RVT and GSH. A computer simulation based on the developed model adequately describes the features of the process kinetics in a wide reactant concentration range.