[RuIII(EDTA)(H2O)]− catalyzed oxidation of biologically important thiols by H2O2. Issue 22 (16th November 2016)

• Record Type: Journal Article
• Authors: Sarkar, Papiya; Saha, Amrita; Chatterjee, Debabrata
• Is Part Of: Journal of coordination chemistry. Volume 69:Issue 22(2016)
• Page Start: 3417
• Page End: 3423
• Publication Date: 2016-11-16
• Subjects: Ruthenium-EDTA -- thiol oxidation -- H2O2 -- kinetics -- mechanism; Coordination compounds -- Periodicals; 541.2242
• DOI: 10.1080/00958972.2016.1229477
• Languages: English
• ISSNs: 0095-8972

Abstract

Abstract: [Ru III (EDTA)(H2 O)] − (EDTA 4− = ethylenediaminetetraacetate) catalyzes the oxidation of biological thiols, RSH (RSH = cysteine, glutathione, N-acetylcysteine, penicillamine) using H2 O2 as precursor oxidant. The kinetics of the oxidation process were studied spectrophotometrically as a function of [Ru III (EDTA)(H2 O)] −, [H2 O2 ], [RSH], and pH (4–8). Spectral analyses and kinetic data are suggestive of a catalytic pathway in which the RSH reacts with [Ru III (EDTA)] catalyst complex to form [Ru III ((EDTA)(SR)] 2− intermediate species. In the subsequent reaction step the oxidant, H2 O2, reacts directly with the coordinated S of the [Ru III ((EDTA)(SR)] 2− intermediate leading to formation of the disulfido (RSSR) oxidation product (identified by HPLC and ESI-MS studies) of thiols (RSH). Based on the experimental results, a working mechanism involving oxo-transfer from H2 O2 to the coordinated thiols is proposed for the catalytic oxidation. Graphical abstract: