Investigation of thiol compounds (L-cysteine, thioacetic acid and ethanethiol) with V(V) and V(IV) using combined spectroscopy and chromatography.

Autor: Knežević L; Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia., Bura-Nakić E; Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address: ebnakic@irb.hr.
Jazyk: angličtina
Zdroj: Journal of inorganic biochemistry [J Inorg Biochem] 2023 May; Vol. 242, pp. 112158. Date of Electronic Publication: 2023 Feb 05.
DOI: 10.1016/j.jinorgbio.2023.112158
Abstrakt: The interactions of V(V) and L-cysteine, thioacetic acid and ethanethiol were studied in aqueous solution using chromatographic and spectral analysis. The chromatographic determination of V(V) and V(IV) species in the presence of thiols was enabled by inducing the ligand exchange reaction with EDTA as the competing ligand. Analytical setup allowed investigation of the possible redox and structural transformations of V(V) in the presence of thiols used over a wide pH range. Obtained data strongly suggest that the reduction of V(V) is proton catalyzed in case of L-cysteine and thioacetic acid. In the case of ethanethiol, the reduction did not seem to be proton dependent, as no reduction was observed above pH = 2. Thus, reduction was inhibited by the deprotonation of L-cysteine and thioacetic acid, with L-cysteine being the strongest reducing agent of V(V), followed by thioacetic acid and finally ethanethiol. Apart from structural thiol properties, the reduction reaction seems to be influenced by the aqueous V(V) speciation due to the observed nonlinear kinetics. In the case of all investigated thiols, the formation of V(V)-thioester intermediate species was an essential step for V(V) reduction. The structural properties of the V(IV)-thiol complexes were also found to be pH-dependent.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier Inc.)
Databáze: MEDLINE
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