Solvent effect on the Thermodynamics of the Oxidation of Potential Antioxidant Garlic Compounds

TL;DR

This study uses quantum chemical calculations to analyze how solvent effects influence the thermodynamics of garlic antioxidant oxidation reactions, revealing that oxidation over the double bond is more feasible, which impacts antioxidant capacity.

Contribution

It provides a detailed thermodynamic analysis of garlic antioxidant oxidation reactions considering solvent effects using advanced quantum chemical methods.

Findings

Oxidation over the double bond is thermodynamically favored.

Solvent effects significantly influence oxidation thermodynamics.

The oxidation leading to epoxide formation limits antioxidant capacity.

Abstract

Antioxidant capacity of garlic has been attributed to organic sulfur compounds such us allyl methyl disulfide. Using quantum chemical calculations at B3LYP/6-31+G (d) and G3MP2B3/6-31+G (d) levels of theory, we study three possible oxidation reactions of this compound against hydrogen peroxide, a reactive oxygen species, from a thermodynamic point of view. Because these reactions are supposed to occur in biological media, solvent effect was taken into consideration. Oxidation over the double bond that leads to the formation of an epoxide is more thermodynamically feasible, limiting the antioxidant capacity of this compound.