Novel Trolox derivatives as antioxidant: A DFT investigation

Abstract

In this paper the antioxidant activity of Trolox derivatives were investigated by density function theory and polarization continuum model as solvent model in order to propose the novel derivatives with higher antioxidant activity from a theoretical viewpoint. The effects of various ortho and meta substituents on the reaction enthalpies of antioxidant mechanisms of Trolox were investigated. Also the effect of reducing the number of atoms in the heterocyclic ring and effect of replacing the oxygen heteroatom of Trolox with other heteroatoms on the antioxidant activity of Trolox were evaluated. Results show that the NH2, OH and NHMe substituents in meta and ortho positions decrease the BDE and IP values and also increase the antioxidant activity of Trolox from the theoretical viewpoint. The derivatives e, c and d with NH, S and Se instead of O have higher antioxidant activity from the theoretical viewpoint. Obtained results show that reducing the number of atom in the heterocyclic ring (derivatives a and b) decrease the BDE and IP values and also increase the antioxidant activity of Trolox from the theoretical viewpoint. The linear dependencies between BDE of OH bond and IP values of studied Trolox derivatives and corresponding EHOMO and R(O-H) values can be useful to propose novel derivatives with higher antioxidant activity from the theoretical viewpoint.

Keywords

• trolox
• antioxidant
• free radical
• mechanism
• BDE and IP