Issue 33, 2016

Aluminium ion-promoted radical-scavenging reaction of methylated hydroquinone derivatives

Abstract

The effect of the aluminium ion (Al3+) on the scavenging reaction of a 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙), as a reactivity model of reactive oxygen species, with hydroquinone (QH2) and its methylated derivatives (MenQH2, n = 1–4) was investigated using stopped-flow and electrochemical techniques in a hydroalcoholic medium. The second-order rate constants (k) for the DPPH˙-scavenging reaction of the hydroquinones increased with the increasing number of methyl substituents. Upon addition of Al3+, the k values significantly increased depending on the concentration of Al3+. Such an accelerating effect of Al3+ on the DPPH˙-scavenging rates of the hydroquinones results from the remarkable positive shift of the one-electron reduction potential (Ered) of DPPH˙ in the presence of Al3+. These results demonstrate that Al3+, a strong Lewis acid, can act as a radical-scavenging promoter by stabilising the one-electron reduced species of the radical, although Al3+ is reported not only to act as a pro-oxidant but also to strongly interact with biomolecules, showing toxicities.

Graphical abstract: Aluminium ion-promoted radical-scavenging reaction of methylated hydroquinone derivatives

Article information

Article type
Paper
Submitted
11 Jul 2016
Accepted
29 Jul 2016
First published
29 Jul 2016
This article is Open Access
Creative Commons BY license

Org. Biomol. Chem., 2016,14, 7956-7961

Aluminium ion-promoted radical-scavenging reaction of methylated hydroquinone derivatives

I. Nakanishi, K. Ohkubo, Y. Ogawa, K. Matsumoto, T. Ozawa and S. Fukuzumi, Org. Biomol. Chem., 2016, 14, 7956 DOI: 10.1039/C6OB01470D

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements