title: [Metabolism of antiparkinson drugs. An example of competitive hydroxylation].
abstract: The investigation of the metabolism of the antiparkinson drugs trihexyphenidyl (1), pridinol (2) and biperiden (3) revealed a graduate tendency for hydroxylation in the different structural elements: If alicyclic, saturated heterocyclic and aromatic ring systems are present in one compound like in 1, the alicyclic ring system is attacked predominately. The amount of metabolites with hydroxy-groups in the saturated heterocyclic ring is much lower, and no hydroxylation takes place in the aromatic ring. In drugs without alicyclic ring systems like 2 the saturated heterocyclus is attacked preferentially, but also some phenolic metabolites are formed. Consequently the following arrangement of falling hydroxylation-tendency can be established: Formula: see text. Probably this arrangement is of common validity and therefore a prediction on the hydroxylation-tendency of other compounds seems to be possible.
mesh_terms: D000328:Adult; D000978:Antiparkinson Agents / Q000378:metabolism*; D001711:Biotransformation; D001712:Biperiden / Q000378:metabolism; D006801:Humans; D006900:Hydroxylation; D008297:Male; D013058:Mass Spectrometry; D010880:Piperidines / Q000378:metabolism; D013329:Structure-Activity Relationship; D014282:Trihexyphenidyl / Q000378:metabolism
chemical_list: D000978:Antiparkinson Agents; D010880:Piperidines; D001712:Biperiden; D014282:Trihexyphenidyl
vernacular_title: Der Metabolismus von Antiparkinson-Mitteln. Ein Beispiel für konkurrierende Hydroxylierungen.