Quantitative comparison of the actual antioxidant activity of Vitamin C, Vitamin E, and NADH

The object of this fundamental research would reveal the actual antioxidant ability of the antioxidants using thermo-kinetic parameter Delta G(not equal o) which was proposed according to Zhu kinetic model. Kinetic experiments on the reactions between Vitamin C, Vitamin E, and NADH analog (BNAH) with DPPH center dot and (Bu3PhO center dot)-Bu-t radicals were made to measure the reaction rate constants in acetonitrile at 298 K. The Delta G(not equal o) (XH) values of Vitamin C, Vitamin E, and BNAH in acetonitrile at 298 K were estimated, and the bond dissociation free energies Delta G(o) (XH) and kinetic intrinsic barriers Delta G(XH/X)(not equal) of these three antioxidants to release hydrogen atoms were also compared. Only the data of thermo-kinetic parameters Delta G(not equal o) (XH) are consistent with the true oxidation sequence. The order of the actual antioxidant activity of these three antioxidants is Vitamin C > Vitamin E > NADH. All our preliminary results throw light on the nature of actual antioxidant ability of antioxidants, which not only depend on thermodynamic driving force, but also depend on the dynamic resistance. Therefore, thermo-kinetic parameter Delta G(not equal o) is the perfect parameter which can be used as measurement criteria of the actual antioxidant ability of antioxidants.

Automated summary

This study investigates the actual antioxidant abilities of different antioxidants by measuring their thermo-kinetic parameters. The results show that Vitamin C has the highest antioxidant activity, followed by Vitamin E, and NADH has the lowest.