Kinetic modeling of the reversal of antioxidant potency of ?-, ?-, ?- and ?-tocopherols in methyl linoleate peroxidation

Extended, chemically detailed kinetic models at the molecular basis are constructed to identify the reactions involved in the reversal of the antioxidant action of alpha-, beta-, gamma- and delta-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.

Automated summary

Extended, chemically detailed kinetic models were used to study the reversal of antioxidant action of different tocopherols during methyl linoleate oxidation. The significant reactions contributing to the observed antioxidant and pro-oxidant behavior were identified. The findings reveal the complex relationship between antioxidant potency and concentration of tocopherols.