Issue 25, 2023

Disulfide radical anion as a super-reductant in biology and photoredox chemistry

Abstract

Disulfides are involved in a broad range of radical-based synthetic organic and biochemical transformations. In particular, the reduction of a disulfide to the corresponding radical anion, followed by S–S bond cleavage to yield a thiyl radical and a thiolate anion plays critical roles in radical-based photoredox transformations and the disulfide radical anion in conjunction with a proton donor, mediates the enzymatic synthesis of deoxynucleotides from nucleotides within the active site of the enzyme, ribonucleotide reductase (RNR). To gain fundamental thermodynamic insight into these reactions, we have performed experimental measurements to furnish the transfer coefficient from which the standard E0(RSSR/RSSR˙) reduction potential has been determined for a homologous series of disulfides. The electrochemical potentials are found to be strongly dependent on the structures and electronic properties of the substituents of the disulfides. In the case of cysteine, a standard potential of E0(RSSR/RSSR˙) = −1.38 V vs. NHE is determined, making the disulfide radical anion of cysteine one of the most reducing cofactors in biology.

Graphical abstract: Disulfide radical anion as a super-reductant in biology and photoredox chemistry

Supplementary files

Article information

Article type
Edge Article
Submitted
10 apr 2023
Accepted
17 maj 2023
First published
17 maj 2023
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2023,14, 6876-6881

Disulfide radical anion as a super-reductant in biology and photoredox chemistry

Q. Zhu, C. Costentin, J. Stubbe and D. G. Nocera, Chem. Sci., 2023, 14, 6876 DOI: 10.1039/D3SC01867A

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.

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