Binding of chloroform to the cysteine of hemoglobin

The products of the covalent binding of chloroform to rat hemoglobin during microsomal metabolism were isolated and identified by gas chromatography (GC) and mass spectroscopy (MS). After isolation by Proteinase K hydrolysis, amino acid analysis and cellulose thin-layer chromatography (TLC), the major product was identified by GC/MS as N-hydroxymethyl cysteine and a minor product as 2-hydroxythiazolidine-4-carboxylic acid. N-Hydroxymethyl cysteine is proposed to be formed during isolation from the 2-oxothiazolidine-4-carboxylic acid present in the intact hemoglobin.