Metabolism of Chlorpromazine. III. Isolation and Identification of Chlorpromazine-N-Oxide. ∗

Summary

Chlorpromazine-N-oxide (CPNO) has been isolated from human urine and identified as a metabolite of chlorpromazine. Proof is based on the similarity between this product and authentic CPNO with respect to their ultraviolet spectra, color reactions, electrophoretic mobility, and paper chromatographic behavior. Further confirmation has been obtained by oxidation of the metabolite and authentic CPNO to form derivatives (CPNO sulfoxide) which are identical to each other as well as to authentic CPNO sulfoxide. CPNO is not a major human metabolite, but it is voided in somewhat larger amounts than chlorpromazine sulfoxide. Dogs surpass humans in their output of the N-oxide.