Reactivity of food phenols with iron and copper ions: binding, dioxygen activation and oxidation mechanisms - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Journal Articles Food and Function Year : 2014

Reactivity of food phenols with iron and copper ions: binding, dioxygen activation and oxidation mechanisms

Abstract

In this work, the affinity of common dietary phenols (gallic acid, caffeic acid, catechin, and rutin) for iron and copper ions was quantitatively investigated in neutral phosphate buffer as well as the reactivity of the complexes toward dioxygen. Contrasting behaviors were observed: because of the competing phosphate ions, Fe-III binding is much slower than FeII binding, which is rapidly followed by autoxidation of FeII into FeIII. With both ions, O-2 consumption and H2O2 production are modest and the phenolic ligands are only slowly oxidized. By contrast, metal-phenol binding is fast with both Cu-I and Cu-II. With Cu-I, O-2 consumption and H2O2 production are very significant and the phenolic ligands are rapidly oxidized into a complex mixture of oligomers. The corresponding mechanism with Cu-II is hampered by the preliminary rate-determining step of Cu-II reduction by the phenols. The consequences of these findings for the stability and antioxidant activity of plant phenols are discussed.
No file

Dates and versions

hal-02631465 , version 1 (27-05-2020)

Identifiers

Cite

Ezzohra Nkhili, Michele Loonis, Simona Mihai, Hakima El Hajji, Olivier O. Dangles. Reactivity of food phenols with iron and copper ions: binding, dioxygen activation and oxidation mechanisms. Food and Function, 2014, 5 (6), pp.1186 - 1202. ⟨10.1039/c4fo00007b⟩. ⟨hal-02631465⟩
10 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More