Bhabak, Krishna P and Mugesh, Govindasamy (2009) Amide-Based Glutathione Peroxidase Mimics: Effect of Secondary and Tertiary Amide Substituents on Antioxidant Activity. In: Chemistry-An Asian Journal, 4 (6). pp. 974-983.
Full text not available from this repository. (Request a copy)Abstract
A series of secondary and tertiary amide-substituted diselenides were synthesized and studied for their GPx-like antioxidant activities using H2O2 Cum-OOH, and tBuOOH as substrates and PhSH as thiol co-substrate.The effect of substitution at the free -NH group of the amide moiety in the sec-amide-based diselenides on GPx activity was analyzed by detailed experimental and theoretical methods. It is observed that substitution at the free -NH group significantly enhances the GPx-like activities of the sec-amide-based diselenides, mainly by reducing the Se center dot center dot center dot O nonbonded interactions. The reduction in strength of the Se center dot center dot center dot O interaction upon introduction of N,N-dialkyl substituents not only prevents the undesired thiol exchange reactions, but also reduces the stability of selenenyl sulfide intermediates. This leads to a facile disproportionation of the selenenyl sulfide to the corresponding diselenide, which enhances the catalytic activity. The mechanistic investigations indicate that the reactivity of diselenides having sec-or tert-amide moieties with PhSH is extremely slow; indicating that the first step of the catalytic cycle involves the reaction between the diselenides and peroxide to produce the corresponding selenenic and seleninic acids.
| Item Type: | Journal Article |
|---|---|
| Publication: | Chemistry-An Asian Journal |
| Publisher: | Willey interscience |
| Additional Information: | Copyright for this article belongs to Willey interscience. |
| Keywords: | Antioxidants; catalysis; redox chemistry; selenium; thiol exchange. |
| Department/Centre: | Division of Chemical Sciences > Inorganic & Physical Chemistry |
| Date Deposited: | 09 Jul 2009 05:15 |
| Last Modified: | 09 Jul 2009 05:15 |
| URI: | http://eprints.iisc.ac.in/id/eprint/21137 |
Actions (login required)
 |
View Item |
