Antioxidative Action of Ellagic Acid-A Kinetic DFT Study.

Jelena Tošović,Urban Bren

doi:10.3390/antiox9070587

Abstract

Although one can find numerous studies devoted to the investigation of antioxidative activity of ellagic acid (EA) in the scientific literature, the mechanisms of its action have not yet been fully clarified. Therefore, further kinetic studies are needed to understand its antioxidative capacity completely. This work aims to reveal the underlying molecular mechanisms responsible for the antioxidative action of EA. For this purpose, its reactions with HO• and CCl3OO• radicals were simulated at physiological conditions using the quantum mechanics-based test for overall free-radical scavenging activity. The density functional theory in combination with the conductor-like polarizable continuum solvation model was utilized. With HO• radical EA conforms to the hydrogen atom transfer and radical adduct formation mechanisms, whereas sequential proton loss electron transfer mechanism is responsible for scavenging of CCl3OO• radical. In addition, compared to trolox, EA was found more reactive toward HO•, but less reactive toward CCl3OO•. The calculated rate constants for the reactions of EA with both free radicals are in a very good agreement with the corresponding experimental values.

Highlights

In recent years, therapeutic applications of non-drug substances such as functional foods, are progressively increasing
In the previous study of Galano at al. it was found that the dominant species of ellagic acid (EA) present at physiological conditions are neutral (~10.7%) and monoanionic (EA−, ~89.3%) forms, which is in accordance with the reported pKa values (Figure 1) [17]
We investigated the antioxidative mechanisms of a dietary polyphenol EA by utilizing the QM-ORSA methodology

Summary

Introduction

Therapeutic applications of non-drug substances such as functional foods, are progressively increasing. Studies on functional foods represent a cutting-edge topic among nutritional scientists. The significance of bioactive compounds as functional supplements of foods has been well established due to their effectiveness in health promotion by disease prophylaxis or treatment. Special attention has been devoted to investigations of polyphenolic compounds, known for their various nutritional, biologic, and pharmacological effects. In order to provide the health benefits to the consumers, functional foods and nutraceuticals have been supplemented with these compounds in recent years [1]. Ellagic acid (EA) attracts an ever-increasing interest due to its great potential in food technology, as well as in pharmaceutical, medical and cosmetic industries [2]

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