scholarly journals The metabolism of benzyl isothiocyanate and its cysteine conjugate

1977 ◽  
Vol 162 (1) ◽  
pp. 99-107 ◽  
Author(s):  
G Brüsewitz ◽  
B D Cameron ◽  
L F Chasseaud ◽  
K Görler ◽  
D R Hawkins ◽  
...  

1. The corresponding cysteine conjugate was formed when the GSH (reduced glutathione) or cysteinylglycine conjugates of benzyl isothiocyanate were incubated with rat liver or kidney homogenates. When the cysteine conjugate of benzyl isothiocyanate was similarly incubated in the presence of acetyl-CoA, the corresponding N-acetylcysteine conjugate (mercapturic acid) was formed. 2. The non-enzymic reaction of GSH with benzyl isothiocyanate was rapid and was catalysed by rat liver cytosol. 3. The mercapturic acid was excreted in the urine of rats dosed with benzyl isothiocyanate or its GSH, cysteinyl-glycine or cysteine conjugate, and was isolated as the dicyclohexylamine salt. 4. An oral dose of the cysteine conjugate of [14C]benzyl isothiocyanate was rapidly absorbed and excreted by rats and dogs. After 3 days, rats had excreted a mean of 92.4 and 5.6% of the dose in the urine and faeces respectively, and dogs had excreted a mean of 86.3 and 13.2% respectively. 5. After an oral dose of the cystein conjugate of [C]benzyl isothiocyanate, the major 14C-labelled metabolite in rat urine was the corresponding mercapturic acid (62% of the dose), whereas in dog urine it was hippuric acid (40% of the dose). 5. Mercapturic acid biosynthesis may be an important route of metabolism of certain isothiocyanates in some mammalian species.

1968 ◽  
Vol 109 (5) ◽  
pp. 727-736 ◽  
Author(s):  
Sybil P. James ◽  
D. A. Jeffery ◽  
Rosemary H. Waring ◽  
P. B. Wood

1. Rabbits and rats dosed with 1-bromobutane excrete in urine, in addition to butylmercapturic acid, (2-hydroxybutyl)mercapturic acid, (3-hydroxybutyl)mercapturic acid and 3-(butylthio)lactic acid. 2. Although both species excrete both the hydroxybutylmercapturic acids, only traces of the 2-isomer are excreted by the rabbit. The 3-isomer has been isolated from rabbit urine as the dicyclohexylammonium salt. 3. 3-(Butylthio)lactic acid is formed more readily in the rabbit; only traces are excreted by the rat. 4. Traces of the sulphoxide of butylmercapturic acid have been found in rat urine but not in rabbit urine. 5. In the rabbit about 14% and in the rat about 22% of the dose of 1-bromobutane is excreted in the form of the hydroxymercapturic acids. 6. Slices of rat liver incubated with S-butylcysteine or butylmercapturic acid form both (2-hydroxybutyl)mercapturic acid and (3-hydroxybutyl)mercapturic acid, but only the 3-hydroxy acid is formed by slices of rabbit liver. 7. S-Butylglutathione, S-butylcysteinylglycine and S-butylcysteine are excreted in bile by rats dosed with 1-bromobutane. 8. Rabbits and rats dosed with 1,2-epoxybutane excrete (2-hydroxybutyl)mercapturic acid to the extent of about 4% and 11% of the dose respectively. 9. The following have been synthesized: N-acetyl-S-(2-hydroxybutyl)-l-cysteine [(2-hydroxybutyl)mercapturic acid] and N-acetyl-S-(3-hydroxybutyl)-l-cysteine [(3-hydroxybutyl)mercapturic acid] isolated as dicyclohexylammonium salts, N-toluene-p-sulphonyl-S-(2-hydroxybutyl)-l-cysteine, S-butylglutathione and N-acetyl-S-butylcysteinyl-glycine ethyl ester.


1963 ◽  
Vol 44 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Wilhelm Dirscherl ◽  
Helmut Thomas

ABSTRACT Perfusion of rat liver with vanillic acid yielded only one metabolite. In paper chromatography with three different solvent systems, the substance showed the same RF-values as vanillyolglycine (3-methoxy-4-hydroxyhippuric acid) and in mixed chromatograms there was only one single spot. After separation by column chromatography, the UV- and IRspectra of the reaction product were identical with those of 3-methoxy4-hydroxy-hippuric acid. During the perfusion experiment, the kinetics of the conjugation were investigated.


1994 ◽  
Vol 22 (2) ◽  
pp. 72-80
Author(s):  
Lorraine D. Buckberry ◽  
Harriet J. Adcock ◽  
Jeremy Adler ◽  
Ian S. Blagbrough ◽  
Peter J. Gaskin ◽  
...  

L-Cysteine conjugates are normally metabolised via N-acetylation to produce a mercapturic acid. However, a recently identified metabolic route (C-S lysis) may lead to the generation of an unstable thiol which has been demonstrated to be responsible for toxicity in various mammalian species. Human Chang liver cells were challenged with a number of established L-cysteine conjugates. The cellular toxicity of these compounds was determined using a range of assay procedures, which provided differing information, depending on the assay method used. These observations were then investigated in order to establish which system would provide the most reliable indication of C-S lyase toxicity and whether any information on the mechanism of action could be obtained by these assay methods.


1978 ◽  
Vol 253 (12) ◽  
pp. 4327-4332
Author(s):  
D. Kioussis ◽  
L. Reshef ◽  
H. Cohen ◽  
S.M. Tilghman ◽  
P.B. Iynedjian ◽  
...  

1979 ◽  
Vol 254 (5) ◽  
pp. 1537-1539 ◽  
Author(s):  
J. Carlstedt-Duke ◽  
O. Wrange ◽  
E. Dahlberg ◽  
J.A. Gustafsson ◽  
B. Högberg

Steroids ◽  
1981 ◽  
Vol 37 (4) ◽  
pp. 409-421 ◽  
Author(s):  
Ashutosh Banerji ◽  
Mohammed Kalimi

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