Reactive sulfur species: hydrolysis of hypothiocyanite to give thiocarbamate-S-oxide.
Hypothiocyanite (OSCN-) hydrolyzes under alkaline conditions to give thiocarbamate-S-oxide (H2NC(=O)SO-, the conjugate base of carbamothioperoxoic acid) via a mechanism that involves rate-limiting nucleophilic attack of OH- on OSCN-, followed by fast protonation (with no net consumption of H+/OH- at pH 11.7). Thiocarbamate-S-oxide has been characterized by 13C NMR, 15N NMR, UV spectroscopy, and ion chromatography. It has also been independently synthesized by the reaction of thiocarbamate (H2NC(=O)S-) and hypochlorite (OCl-). The properties of thiocarbamate-S-oxide that is produced by hydrolysis of OSCN- and by oxidation of H2NC(=O)S- are the same. The possible relevance of thiocarbamate-S-oxide in human peroxidase defense mechanisms remains to be explored.
Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA.
Péter
P
Nagy
Xiaoguang
X
Wang
Kelemu
K
Lemma
Michael T
MT
Ashby
D002853:Chromatography, Liquid; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013455:Sulfur / Q000737:chemistry*; D013859:Thiocarbamates / Q000737:chemistry*; D013861:Thiocyanates / Q000737:chemistry*
D013859:Thiocarbamates; D013861:Thiocyanates; C014607:hypothiocyanite ion; D013455:Sulfur