Metabolism of peptido-aminobenzophenone (2-o-chlorobenzoyl-4-chloro-N-methyl-N'-glycyl-glycinanilide) in dogs.

1. The metabolism of a peptido-aminobenzophenone (2-o-chlorobenzoyl-4-chloro-N-methyl-N'-glycyl-glycinanilide) (I) was investigated in dogs after oral administration of 50 mg/kg. 2. Metabolites from urine and plasma extracts were identified by g.l.c., t.l.c., and g.l.c.-mass spectrometry. 3. Metabolites identified in the urine were chlorodiazepam (IV), chlorodesmethyldiazepam (III), lorazepam (II), an oxalanilic acid derivative (X). In the plasma, III and IV were detected. 4. The major urinary metabolite was a lorazepam conjugate. 5. A possible main metabolic pathway of I involves formation of the desglycyl compound (XII) via hydrolysis of the terminal amino acid and cyclization to the benzodiazepine type followed by demethylation, 3-hydroxylation and finally conjugation. 6. Formation of the oxanilic acid derivative X from I was a minor route.