Abstract:
Density functional theory (DFT) was used to explore the antioxidant properties of some
naturally occurring dietary vitamins, and the reaction enthalpies related to various mechanisms of
primary antioxidant action, i.e., hydrogen atom transfer, single electron transfer–proton transfer,
and sequential proton loss–electron transfer were discussed in detail. B3LYP, M05-2X, and M06-2X
functionals were utilized in this work. For aqueous phase studies, the integral equation formalism
polarized continuum model (IEF–PCM) was employed. From the outcomes, hydrogen atom transfer
(HAT) was the most probable mechanism for the antioxidant action of this class of compounds.
Comparison of found results with experimental data (available in literature), vitamin C possesses
the lowest enthalpy values for both proton a nity (PA) and bond dissociation energy (BDE)in the
aqueous phase, suggesting it as the most promising candidate as an antioxidant. Accordingly, these
computational insights encourage the design of structurally novel, simple vitamins which will be
more economical and beneficial in the pharmaceutical industry.
