![Sample our Bioscience journals, sign in here to start your access, Latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5925/TOC-Subject-Sample-2021-Bioscience.jpg"})
Abstract
1. The metabolism of 2-cyano-3-phenylacrylic acid (CPA) and some methyl 2-cyano-3-phenylacrylates (methyl α-cyanocinnamates) after i.p. administration to rats, was investigated.
2. The conjugation of CPA and methyl α-cyanocinnamates with L-cysteine, N-acetylcysteine and glutathione (GSH) in vitro was studied and the rate of hydrolysis of the double bond of the methyl α-cyanocinnamates determined.
3. CPA and the methyl α-cyanocinnamates caused a significant increase in urinary (24 h) thioether excretion, with no increase in SCN− excretion.
4. No thioethers, such as possible addition products of N-acetylcysteine with CPA or methyl α-cyanocinnamates, were isolated; such thioether compounds appeared to be very unstable.
5. Administration of the carboxylesterase inhibitor, tri-ortho tolyl phosphate, to rats resulted in increased urinary excretion of SCN− but no significant excretion of thioethers, after a single i.p. injection of methyl α-cyanocinnamates.
6. Following incubation of methyl α-cyanocinnamates with GSH under non-enzymic and enzymic conditions, the GSH was 100% recovered. However, incubation of CPA depleted GSH and N-acetylcysteine (non-enzymic).
7. A metabolic pathway for the metabolism of methyl α-cyanocinnamates to thioether adducts is proposed, which proceeds via the corresponding CPA. Ester hydrolysis and the carbon-carbon double bond hydrolysis are probably in vivo reactions of some importance.