Abstract
The conversion of S-nitrosothiols to thiosulphonates by reaction with the sodium salt of benzenesulfinic acid (PhSO(2)Na) has been examined in detail with the exemplary substrates S-nitrosoglutathione (GSNO) and S-nitrosylated bovine serum albumin (SNO-BSA). The reaction stoichiometry (2:1, PhSO(2)Na:RSNO) and the rate law (first order in both PhSO(2)Na and RSNO) have been determined under mild acidic conditions (pH 4.0). The products have been identified as the corresponding thiosulphonates (GSSO(2)Ph and BSA-SSO(2)Ph) along with PhSO(2)NHOH obtained in a 1:1 ratio. GSH, GSSG, and BSA were unreactive to PhSO(2)Na.