Metabolism of triallate in Sprague-Dawley rats. 2. Identification and quantitation of excreted metabolites

[C-13,C-14]Triallate was administered orally to Sprague-Dawley rats. Twelve excreted metabolites were identified, the most abundant being 2,3,3-trichloro-2-propenesulfinic acid. Five metabolites derived from 2,3,3-trichloro-2-propenethiol were identified in excreta, including a methyl sulfone mercapturate whose structure was confirmed by X-ray crystallography. Three 2-chloroacrylate metabolites were identified, including a 2-chloroacrylate mercapturate whose structure was confirmed by X-ray crystallography. 2,3,3-Trichloro-2-propenol and hydroxytriallate were also identified as metabolites. Dosing of radiolabeled thiol and sulfinic acid to separate animals resulted in excretion of only thiol-derived metabolites in the urine of thiol-dosed rats, while sulfinic acid and sulfonic acid were excreted by sulfinic acid-dosed rats. Triallate metabolism in rats proceeds via three main pathways, i.e., S-oxidation leading to sulfur acids, 8-oxidation/hydrolysis/reduction leading to thiol derivatives, and C-oxidation of the 2,3,3-trichloropropenethiol moiety. This study demonstrates that formation of readily excreted sulfur acids and thiol derivatives is the major route of triallate metabolism in rats.