The metabolism of benzyl isothiocyanate and its cysteine conjugate in guinea-pigs and rabbits

Xenobiotica. 1982 Sep;12(9):535-42. doi: 10.3109/00498258209038932.


1. Following oral administration of benzyl isothiocyanate or its cysteine conjugate the major metabolite isolated from urine of guinea-pigs and rabbits was a cyclic mercaptopyruvate conjugate, 4-hydroxy-4-carboxy-3-benzylthiazolidin-2-thione. 2. Renal excretion of the metabolite after oral administration of benzyl isothiocyanate or its cysteine conjugate to guinea-pigs amounted to 23% and 33% respectively. The corresponding N-acetylcysteine conjugate of benzyl isothiocyanate (a mercapturic acid) was present as a minor metabolite. 3. After oral or i.v. administration of the glutathione, cysteinylglycine, cysteine or N-acetylcysteine conjugates of benzyl isothiocyanate to guinea-pigs, the major metabolite in urine was 4-hydroxy-4-carboxy-3-benzylthiazolidin-2-thione, with the N-acetylcysteine conjugate of benzyl isothiocyanate present in traces only. 4. It is concluded that during formation of the cyclic mercaptopyruvate conjugate, the cysteine conjugate predominantly undergoes transamination, and only a small proportion undergoes N-acetylation.

MeSH terms

  • Animals
  • Chemical Phenomena
  • Chemistry
  • Chromatography, Thin Layer
  • Cysteine / analogs & derivatives*
  • Cysteine / metabolism
  • Guinea Pigs
  • Isothiocyanates*
  • Magnetic Resonance Spectroscopy
  • Male
  • Rabbits
  • Thiazoles / urine
  • Thiazolidines
  • Thiocyanates / metabolism*


  • Isothiocyanates
  • Thiazoles
  • Thiazolidines
  • Thiocyanates
  • S-(N-benzylthiocarbamoyl)cysteine
  • 4-hydroxy-4-carboxy-3-benzylthiazolidin-2-thione
  • benzyl isothiocyanate
  • Cysteine