[Biotransformation of denaverin (Spasmalgan) in the rat]

After oral application of denaverine hydrochloride to rats (200-250 mg/kg) 12 metabolites have been detectecd in urine. Besides the unchanged drug, 8 metabolites were identified by MS as 2,2-diphenyl-(2-dimethylaminoethyl) acetate (3), diphenylacetic (5) and benzilic acid (6); methyl-and ethyl [2-(2-ethylbutoxy)-2,2-diphenyl]acetate (7, 11), methylbenzilate (10), N-demethyl-1 (12) and 3,3-diphenyl-morpholin-2-one (13). 6 and the metabonate 13 represent the main metabolic products. Compounds 7 and 11 indicate the metabolic pathway about an alkoxybenzilic acid (4). Phenols resp. conjugates were not detected.