Introduction of a catalytic triad increases the glutathione peroxidase-like activity of diaryl diselenides

Bhowmick, Debasish and Mugesh, Govindasamy (2014) Introduction of a catalytic triad increases the glutathione peroxidase-like activity of diaryl diselenides. In: ORGANIC & BIOMOLECULAR CHEMISTRY, 13 (34). pp. 9072-9082.

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Abstract

Reactive oxygen species (ROS)-mediated diseased states are of major concern in modern day life. Under oxidative stress conditions, the cellular antioxidants deplete, leading to several biological disorders. Small molecule mimics of different antioxidant enzymes are found to be useful in supplementing the biological systems to detoxify ROS. In this study, we have synthesized a series of amine or amide-based diselenides containing an additional amino group as glutathione peroxidase (GPx) mimetics. These diselenides act as a catalytic triad model of the native GPx featuring two basic amino groups near the selenium centre. A comparison of the catalytic activities reveals that the additional amino group increases the activity significantly in the presence of aromatic thiols. Deprotonation of thiol by an additional amine either stabilizes the selenolate intermediate or facilitates the nucleophilic attack of thiol in other intermediates. The Se-77 NMR experiments and DFT calculations show that the amino group does not have any significant effect on the catalytic intermediates. Although the amino moiety increases the nucleophilicity of the thiol, it does not prevent the thiol exchange reactions that take place in the selenenyl sulfide intermediates.

Item Type:	Journal Article
Publication:	ORGANIC & BIOMOLECULAR CHEMISTRY
Publisher:	ROYAL SOC CHEMISTRY
Additional Information:	Copy right for this article belongs to the ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	24 Sep 2015 06:36
Last Modified:	24 Sep 2015 06:36
URI:	http://eprints.iisc.ac.in/id/eprint/52420

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