Mercapturic add

Phenyl-mercapturic add Benzene Urine 9h No Traffic, combustion products... 

Scheme 3 Metabolic pathways of PCB biotransformation in vertebrates. MAP, mercapturic add pathway GSH, glutathione, Cys, cysteine...

The stereoselectivity of GSTs toward a considerable number of substrates has been described (Fig. 7) (Vermeulen and Breimer, 1983 Armstrong, 1987 van Bladeren, 1988 te Koppele and Mulder, 1991). With regard to rigid epoxides, it was found by identif)nng and quantifying mercapturic adds excreted in the urine of rats treated with the model compound cyclohexene oxide, that only two fr[Pg.259]

A few alkenes react with glutathione, or cysteine, to form a mercapturic acid precursor (Section VI, F). It has been suggested that some alkyl halides may be dehalogenated to an alkcnc (James and White, 1967).The alkene could be converted to an epoxide or could add the glutathione directly by a reaction catalyzed bj an S-glutathione transferase (Boyland and Chasseaud, 1968). At present the activity of the enzyme is chiefly related to the reaction of glutathione with aS unsaturated esters which do not form mercapturic acids in vioo. 

---