Kinetic modeling of the reversal of antioxidant potency of α-, β-, γ- and δ-tocopherols in methyl linoleate peroxidation

Abstract

Extended, chemically detailed kinetic models at the molecular basis are constructed to identify the reactions involved in the reversal of the antioxidant action of α-, β-, γ- and δ-tocopherols during methyl linoleate oxidation. The reaction mechanisms were numerically simulated and subjected to analysis to quantify the significance of individual chemical steps by the value-based method. Results of the obtained kinetic models agreed well with the experimental data. The significant individual reactions contributing to the observed antioxidant and pro-oxidant behavior of the different tocopherols were identified. It is revealed that the reverse order of antioxidant potency and a complex nonlinear dependency of the antioxidant potency of tocopherols with the increase in their concentration are due to the increasing contribution of pro-oxidant relative to the antioxidant reactions. Once the approach presented here can be applied to more complex systems, engineered optimization of antioxidant protection strategies may be reached.

Keywords: Antioxidants; Kinetic model; Lipid peroxidation; Numerical simulation; Tocopherols; Vitamin E; methyl linoleate (PubChem CID: 5284421); α-tocopherol (PubChem CID: 1742129); β-tocopherol (PubChem CID: 6857447); γ-tocopherol (PubChem CID: 92729); δ-tocopherol (PubChem CID:92094).