title: Synthesis and biological evaluation of bivalent ligands for the cannabinoid 1 receptor.
abstract: Dimerization or oligomerization of many G-protein-coupled receptors (GPCRs), including the cannabinoid 1 (CB1) receptor, is now widely accepted and may have significant implications for medications development targeting these receptor complexes. A library of bivalent ligands composed of two identical CB1 antagonist pharmacophores derived from SR141716 linked by spacers of various lengths were developed. The affinities of these bivalent ligands at CB1 and CB2 receptors were determined using radiolabeled binding assays. Their functional activities were measured using GTP-γ-S accumulation and intracellular calcium mobilization assays. The results suggest that the nature of the linker and its length are crucial factors for optimum interactions of these ligands at CB1 receptor binding sites. Finally, selected bivalent ligands (5d and 7b) were able to attenuate the antinociceptive effects of the cannabinoid agonist CP55,940 (21) in a rodent tail-flick assay. These novel compounds may serve as probes that will enable further characterization of CB1 receptor dimerization and oligomerization and its functional significance and may prove useful in the development of new therapeutic approaches to G-protein-coupled receptor mediated disorders.
authors.affiliation: Research Triangle Institute, Research Triangle Park, North Carolina 27709, USA. yzhang@rti.org
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Anne
authors.initials: A
authors.lastname: Gilliam
authors.forename: Rangan
authors.initials: R
authors.lastname: Maitra
authors.forename: M Imad
authors.initials: MI
authors.lastname: Damaj
authors.forename: Julianne M
authors.initials: JM
authors.lastname: Tajuba
authors.forename: Herbert H
authors.initials: HH
authors.lastname: Seltzman
authors.forename: Brian F
authors.initials: BF
authors.lastname: Thomas
mesh_terms: D000700:Analgesics / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003511:Cyclohexanols / Q000494:pharmacology; D054314:Drug Inverse Agonism; D006801:Humans; D066298:In Vitro Techniques; D008024:Ligands; D008297:Male; D051379:Mice; D055503:Protein Multimerization; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D043885:Receptor, Cannabinoid, CB2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000700:Analgesics; D003511:Cyclohexanols; D008024:Ligands; C553287:N,N'-(iminodiheptane-7,1-diyl)bis(5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide); C553288:N-(3-((3-aminopropyl)amino)propyl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; C054649:3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol; D002118:Calcium