Copper-assisted oxidation of catechols into quinone derivatives.
Fiche publication
Date publication
décembre 2020
Journal
Chemical science
Auteurs
Membres identifiés du Cancéropôle Est :
Dr CHERIOUX Frédéric
Tous les auteurs :
Gómez-Herrero AC, Sánchez-Sánchez C, Chérioux F, Martínez JI, Abad J, Floreano L, Verdini A, Cossaro A, Mazaleyrat E, Guisset V, David P, Lisi S, Martín Gago JA, Coraux J
Lien Pubmed
Résumé
Catechols are ubiquitous substances often acting as antioxidants, thus of importance in a variety of biological processes. The Fenton and Haber-Weiss processes are thought to transform these molecules into aggressive reactive oxygen species (ROS), a source of oxidative stress and possibly inducing degenerative diseases. Here, using model conditions (ultrahigh vacuum and single crystals), we unveil another process capable of converting catechols into ROSs, namely an intramolecular redox reaction catalysed by a Cu surface. We focus on a tri-catechol, the hexahydroxytriphenylene molecule, and show that this antioxidant is thereby transformed into a semiquinone, as an intermediate product, and then into an even stronger oxidant, a quinone, as final product. We argue that the transformations occur two intramolecular redox reactions: since the Cu surface cannot oxidise the molecules, the starting catechol and the semiquinone forms each are, at the same time, self-oxidised and self-reduced. Thanks to these reactions, the quinone and semiquinone are able to interact with the substrate by readily accepting electrons donated by the substrate. Our combined experimental surface science and analysis highlights the key role played by metal nanoparticles in the development of degenerative diseases.
Référence
Chem Sci. 2020 Dec 21;12(6):2257-2267