Metabolism of 2-thiobenzothiazoles in the rat. Urinary, fecal and biliary metabolites of 2-benzothiazyl sulfenamides.

Metabolic fates of 2-benzothiazyl sulfenamides, N-oxydiethylene-2-benzothiazyl sulfenamide and N-cyclohexyl-2-benzothiazyl sulfenamide in rats were studied using tracer technique. These compounds given orally to rats were excreted rapidly in the urine and feces. Five urinary metabolites, 2-mercaptobenzothiazole (MBT), its three conjugates, mercapturate, glucuronide and sulfate, and 2,2′-dibenzothiazyl disulfide (BTDS) were confirmed. Furthermore, BTDS was found as a fecal metabolite. The sulfenamides were partly transformed in the stomach to BTDS, which was predominantly excreted into the feces. In the liver, the sulfenamides were mainly transformed to MBT and its conjugates. The S-glucuronide and S-sulfate conjugates were predominantly excreted into the bile. Mechanisms were discussed concerning the metabolite formation of sulfenamide derivatives in vivo and in vitro.