Detection of 1-acetamino-3-(1-naphthyloxy)-2-propanol as a new metabolite of propranolol.

1-Acetamino-3-(1-naphthyloxy)-2-propanol which is an acetyl conjugate of N-desisopropylpropranolol (AcNDP) was detected as a new metabolite of propranolol (PL) from the incubation medium of isolated rat hepatocyte system and from the urinary extracts of a patient under PL therapy as well as a healthy volunteer given PL. In the case of the hepatocyte systems, the optical selectivity of PL elimination and the metabolite formation were discussed by HPLC determination, and the effect of pretreatment by phenobarbital (PB) or 3-metylcholanthrene (3-MC) on the metabolism was also clarified.