title: Dopamine agonists related to 3-allyl-6-chloro-2,3,4,5-tetrahydro-1-(4-hydroxyphenyl)-1H-3-benzaz epi ne-7, 8-diol. 6-Position modifications.
abstract: The N-allyl derivative (SK&F 85174) of 6-chloro-2,3,4,5-tetrahydro-1-(4-hydroxyphenyl)-1H-3-benzazepine-7,8-diol (SK&F 82526) retains the DA-1 agonist potency of the latter compound but unlike the parent also shows substantial DA-2 agonist activity. In a previous study of N-substituted benzazepines these combined agonist effects were shown to be uniquely associated with the N-allyl group. A continuation of this research has examined dependency of combined DA-2/DA-1 agonist activities on 6-position modification with the specific objective of developing an agonist with maximum effectiveness and potency at the DA-2 receptor subtype. DA-2 agonist activity was measured in a rabbit ear artery assay, and DA-1 agonist activity was determined in an adenylate cyclase assay. Replacing chloro with bromo retains the activity pattern and the potency of the chloro compound; replacement with a hydrogen causes a decrease of both DA-1 and DA-2 receptor activating potency. Introduction of a 6-methyl group causes loss of DA-2 agonist activity and reduction in DA-1 agonist potency. Substitution with a 6-fluoro provides the best balance of DA-2 and DA-1 agonist activities; this compound was moderately potent in both assays.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001552:Benzazepines / Q000138:chemical synthesis* / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D011817:Rabbits; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology*; D013329:Structure-Activity Relationship
chemical_list: D001552:Benzazepines; D007202:Indicators and Reagents; D011954:Receptors, Dopamine; C045977:SK&F 85174; D000262:Adenylyl Cyclases; D004298:Dopamine