In Vitro Transformation of Thiazopyr by Rat Liver Enzymes: Sulfur and Carbon Oxidations by Microsomes

• Published in: Pesticide biochemistry and physiology Vol. 48; no. 1; pp. 8 - 14
• Main Authors: Feng, P.C.C., Solsten, R.T., Mcclanahan, R.H.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 1994; Elsevier
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; AZUFRE; Biological and medical sciences; CARBONE; CARBONO; DESARROLLO DE UN PRODUCTO; DEVELOPPEMENT DE PRODUIT; ENZIMAS; ENZYME; EXPERIMENTACION IN VITRO; EXPERIMENTATION IN VITRO; FOIE; HERBICIDAS; HERBICIDE; HIGADO; Medical sciences; METABOLISME; METABOLISMO; METABOLITE; METABOLITOS; ORGANITE CELLULAIRE; ORGANULOS CITOPLASMICOS; OXIDACION; OXYDATION; Pesticides, fertilizers and other agrochemicals toxicology; PIRIDINAS; PYRIDINE; RAT; RATA; SOUFRE; Toxicology; VIA BIOQUIMICA DEL METABOLISMO; VOIE BIOCHIMIQUE DU METABOLISME; Rat; Liver; Rodentia; Pesticides; Microsome; Metabolism; In vitro; Herbicide; Pyridine derivatives; Toxicokinetics; Vertebrata; Mammalia; Animal; Oxidation
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1006/pest.1994.1002

Thiazopyr is an experimental herbicide from the pyridine family that shows excellent preemergent activity against narrow-leafed weeds. Biotransformation of thiazopyr was examined in vitro using rat liver microsomes to assess the extent of its metabolism in vivo. Thiazopyr was rapidly and extensively oxidized exclusively in the thiazoline ring. The sulfur atom in the thiazoline ring was sequentially oxidized to the corresponding sulfoxide and sulfone metabolites. Oxidation of the carbon atoms in the thiazoline ring produced carbinolimine intermediates, which underwent dehydration or arrangements leading to the opening of thiazoline ring. A total of six metabolites were identified based on electrospray LC/MS and/or cochromatography with standards.