Abstract
In order to investigate the stability of selenomethionine (SeMet), the oxidation reaction of selenomethionine (SeMet) with an oxygen atom was studied by the density function theory (DFT) method. The structures of reactants, transition state and products were fully optimized at the B3LYP/6-311G** level. Intrinsic reaction coordinate (IRC) calculations were carried out to ensure the validity of the reaction path. The thermodynamic functions, namely entropy, enthalpy, free energy and equilibrium constant, and the reaction rate constant k in Eyring transition state theory, were also calculated. It has been shown that the SeMet oxidation process is favoured at lower temperatures, which might have implications for the storage stability of selenomethionine (SeMet) at lower temperatures.