Unveiling the Antioxidative Potential of Galangin: Complete and Detailed Mechanistic Insights through Density Functional Theory Studies

A comprehensive quantum mechanical investigation into the antioxidative activity of galangin (Glg) was conducted. Thermochemical and kinetic data were utilized to assess the antiradical, chelating, and renewal potential of all Glg species under physiological conditions. Initially, a brief comparison was made using the eH-DAMA method between reference antioxidants and other studied flavonoids characterising the substance as a moderate antioxidative agent. Also, Glg’s significantly lesser performance in lipid compared to aqueous solvent was noted. The reaction rates for scavenging •OOH in both media were established at 3.77 × 103 M-1 s-1 and 6.21 × 104 M-1 s-1, respectively, accounting for the molar fraction of both interacting molecules at the given pH. The impact of pH on the kinetics of the processes in water was also assessed. Although capable of efficiently chelating Cu(II) ions, the metal in such complexes can still easily undergo the Fenton reaction. However, the formed complexes persistently exhibit a capability to scavenge •OH in statu nascendi. Moreover, the flavonoid itself was found to effectively repair all oxidatively damaged biomolecules except model lipid acids. Since all Glg radical species were found to be readily restored by the physiologically prevailing O2•-, the polyphenol is expected to participate in antiradical and regenerating activities multiple times, amplifying its antioxidative potential.