Methyl mercapturate synthesis: an efficient, convenient and simple method

A safe and simple method for methyl S-arylmercapturate synthesis is described. Thirteen such compounds, to be used afterwards in metabolism studies, have been obtained with yields ranging from 71 to 99.6%. These compounds were obtained using a sulfa-Michael addition and synthesized by adding the corresponding thiophenols to a mixture composed of methyl 2-acetamidoacrylate (MAA), potassium carbonate and a phase transfer catalyst, Aliquat 336. MAA, the initial synthon, was itself isolated in quasi quantitative yield following a fully described synthesis.

N-acetyl-S-(2-hydroxyethyl)-L-cysteine as a potential tool in biological monitoring studies? A critical evaluation of possibilities and limitations

In mammalian species, including man, N-acetyl-S-(2-hydroxyethyl)-L-cysteine (2-HEMA) is a common urinary metabolite of a large number of structurally different xenobiotic chemicals. It is a common urinary end product of glutathione pathway metabolism of a variety of chemicals possessing electrophilic properties and, in most cases, also a genotoxic potential. Five different chemically reactive intermediates, with different electrophilic properties, may be involved in the formation of 2-HEMA. An inventory of chemicals known to lead to the formation of 2-HEMA, or based on their chemical structure expected to do so, is presented. Furthermore, an attempt is made to evaluate the possibilities and limitations in terms of the potential use of urinary 2-HEMA as a tool in biomonitoring studies. Two other related, sulfur-containing urinary metabolites, i.e. N-acetyl-(S-carboxymethyl)-L-cysteine and thio-diacetic acid, are proposed as possible alternatives to urinary 2-HEMA. It is suggested that 2-HEMA might be seen as a potentially useful and sensitive signal parameter for the assessment of exposure of animals and man to a variety of electrophilic and therefore potentially toxic xenobiotic chemicals.