Biochemical studies on toxic agents. 12. The biosynthesis of n-propylmercapturic acid from n-propyl halides.

Before the preliminary account of the present work (Grenby & Young, 1959) there appears to have been no report of the isolation of a biosynthetic alkylmercapturic acid. Evidence had been obtained, however, which suggested that alkylmercapturic acids could probably be isolated from the urine of animals which had been dosed with certain alkylating agents. Roberts & Warwick (1957, 1958), by means of radiochromatography, showed the presence of ethylmercapturic acid in the urine of rats which had been dosed with ethyl methanesulphonate. By chromatographic and radiochromatographic methods ethylmercapturic acid was also detected in the urine of rats after administration of bromoethane (Thomson, Maw & Young, 1958), and by the use of a procedure for determining mercapturic acids Bray & James (1958) demonstrated the excretion of alkylmercapturic acids by animals dosed with 1and 2-bromobutane and certain higher 1-bromoalkanes. The present work was undertaken to determine whether the three n-propyl halides, 1-chloro-, 1-bromoand 1-iodo-propane, give rise in the animal body to n-propylmercapturic acid, i.e. N acetyl S (n-propyl) -L cysteine. 1Fluoropropane (b.p. -3 2°) was not studied. NH-CO-CH3