Thiodiglycol sulphoxide

Black, R.M., Read, R.W. (1991). Methods for the analysis of thiodiglycol sulphoxide, a metabolite of sulphur mustard, in urine using gas chromatography-mass spectrometry. J. Chro-matogr. 558 393-404. 

Diphenyl sulphoxide, thiodiglycol sulphoxide, and diethyl sulphoxide are oxidised to the corresponding sulphones. Howard and Levitt studied the kinetics of oxidation of these compounds at pH 8 in a phosphate buffer (aqueous solution) and found the rates to be first-order with respect to peroxodisulphate and independent of the substrate concentration over the limited range employed (0.01-0.02 M). The removal of oxygen had no effect on the rate. Diethyl sulphide is oxidised very rapidly initially, then at the same rate as diethyl sulphoxide. Howard and Levitt concluded that the sulphide is first oxidised to the sulphoxide which in turn is oxidised to the sulphone, but Wilmarth and Haim point out that this interpretation cannot be correct, and conclude that the reaction must be more complex. 

Figure 2.1 Metabolic breakdown of SM. Proposed metabolic fate of SM (adapted from Black et alX). Metabolites are 1 SM 2 thiodiglycol 3 thiodi-glycol sulphoxide 4 mustard sulphoxide 5 mono-GSH-SM adduct 6 l-[S-(iV-acetylcysteinyl)]-2-(2-chloroethylsulphinyl)ethane 7 l-[S-(Af-acetylcysteinyl)]-2-(2-chloroethylsulphonyl)ethane 8 1-[S-(N-acetylcysteinyl)]-2-(ethenylsulphonyl)ethane 9 di-GSH-SM adduct 10 l,l -sulphonylbis[(2-5 -cysteinyl)ethane] 11 l,l -sulphonylbis[2-S-(Af-acetylcysteinyl)ethane] 12 l,l -sulphonylbis(ethan-2-thiol) (putative intermediate indicated by square brackets) 13 l,l -sulphonyl-bis[2-(methylthio)ethane] 14 l-methylsulphinyl-2-[2-(methylthio)eth-ylsulphonyljethane 15 l,l -sulphonylbis[2-(methylsulphinyl)ethane].

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