Zhao Hongdi, Zhao Yu, Yan Hongyan, et al. Reaction mechanism of OH· radical scavenging by GA in weak acidic and weak alkaline aqueous environments in living organisms based on DFT[J/OL]. Acta Scientiarum Naturalium Universitatis Sunyatseni, 2026, 1-11.
DOI:
Zhao Hongdi, Zhao Yu, Yan Hongyan, et al. Reaction mechanism of OH· radical scavenging by GA in weak acidic and weak alkaline aqueous environments in living organisms based on DFT[J/OL]. Acta Scientiarum Naturalium Universitatis Sunyatseni, 2026, 1-11.DOI: 10.11714/acta.snus.ZR20260085.
Reaction mechanism of OH· radical scavenging by GA in weak acidic and weak alkaline aqueous environments in living organisms based on DFT
The mechanism of gallic acid (GA) scavenging hydroxyl radical (OH·) in weak acidic and weak alkaline aqueous environments of living organisms was investigated using the M06-2X functional method. The reaction between GA and OH· involves three pathways: 1) Hydrogen abstraction, addition, and single-electron transfer. Calculations show that for the hydrogen abstraction reaction, the optimal pathway under both weak acidic and weak alkaline aqueous environments is the abstraction of the hydroxyl hydrogen by OH·, which is significantly exothermic and barrierless. The suboptimal pathway is the abstraction of the hydrogen at the 10-position on the benzene ring by OH·, with energy barriers of 13.5 and 61.2 kJ/mol under weak acidic and weak alkaline aqueous environments, respectively, and the reactions are exothermic. 2) For the addition reaction, the optimal pathways under weak acidic and weak alkaline aqueous environments exhibit energy barriers of 23.8 and 46.0 kJ/mol, respectively, and are exothermic. 3) For the single-electron transfer reaction, the energy barrier is 5.0 kJ/mol under weak acidic aqueous environment, and the reaction is significantly exothermic; however, under weak alkaline aqueous environment, this pathway is thermodynamically and kinetically unfavorable. The results indicate that GA acts as an efficient OH· scavenger in both weak acidic and weak alkaline aqueous environments of living organisms, with superior antioxidant performance observed under weak acidic conditions.
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