title: Structure-activity relationship study on N-(1,2,3,4-tetrahydronaphthalen-1-yl)-4-aryl-1-piperazinehexanamides, a class of 5-HT7 receptor agents. 2.
abstract: Here we report the synthesis of N-(1,2,3,4-tetrahydronaphthalen-1-yl)-4-aryl-1-piperazinealkylamides 16-29 that were designed to elucidate both structure-affinity and -activity relationships for the 5-HT7 receptor, by targeting the substituent in 2-position of the aryl linked to the piperazine ring. The affinities of 16-29 for 5-HT7, 5-HT1A, 5-HT2A, and D2 receptors were assessed by radioligand binding assays. The intrinsic activities at the 5-HT7 receptor of the most potent compounds were determined. A series of substituents covering a wide range of electronic, steric, and polar properties was evaluated, revealing a key role on 5-HT7 receptor affinity and intrinsic activity. Certain lipophilic substituents (SCH3, CH(CH3)2, N(CH3)2, CH3, Ph) led to high-affinity agonists, whereas OH and NHCH3 substituents switched intrinsic activity toward antagonism. 4-[2-(1-Methylethyl)phenyl]-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide (19), 4-(2-diphenyl)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide (21), and 4-(2-dimethylaminophenyl)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide (22) were identified as potent 5-HT7 receptor agonists (Ki = 0.13-1.1 nM, EC50 = 0.90-1.77 microM), showing selectivity over 5-HT1A, 5-HT2A, and D2 receptors.
authors.affiliation: Università degli Studi di Bari, Dipartimento Farmaco-Chimico, via Orabona, 4, 70125 Bari, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Leopoldo
authors.forename: Enza
authors.initials: E
authors.lastname: Lacivita
authors.forename: Marialessandra
authors.initials: M
authors.lastname: Contino
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Colabufo
authors.forename: Francesco
authors.initials: F
authors.lastname: Berardi
authors.forename: Roberto
authors.initials: R
authors.lastname: Perrone
mesh_terms: D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D010879:Piperazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects*; D017366:Serotonin Receptor Agonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013764:Tetrahydronaphthalenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: C523822:4-(2-(1-methylethyl)phenyl)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide; C523824:4-(2-dimethylaminophenyl)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide; C523823:4-(2-diphenyl)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1-piperazinehexanamide; D000577:Amides; D010879:Piperazines; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D013764:Tetrahydronaphthalenes; C104425:serotonin 7 receptor