title: Biotransformation of urapidil: isolation and identification of metabolites in mouse, rat, dog and man.
abstract: The identification of biotransformation products of the new antihypertensive drug urapidil in mouse, rat, dog and man has been performed by means of high-performance liquid chromatographic and mass spectrometric techniques. In urine, three metabolites were found in addition to the unchanged drug. The para-hydroxylated product (1) (6-(3-[4-(o-methoxy-p-hydroxyphenyl)piperazinyl]-propylamino)-1, 3-dimethyl-uracil), the O-demethylated compound (2) (6-(3-[4-(o-hydroxyphenyl)piperazinyl]-propylamino)-1, 3-dimethyluracil) and the uracil-N-dealkylated compound (3) (6-(3-[4-(o-methoxyphenyl)piperazinyl]-propylamino)-1-methyluracil). In urine of dog, the metabolite with the N-oxide structure (5) was also identified, but only in trace amounts (6-(3-[4-(o-methoxyphenyl)piperazinyl-N-oxide]-propylamino)-1, 3-dimethyluracil).
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents; D001711:Biotransformation; D004285:Dogs; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D051379:Mice; D010879:Piperazines / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000959:Antihypertensive Agents; D010879:Piperazines; C015568:urapidil