Leveraging a Low-Affinity Diazaspiro Orthosteric Fragment to Reduce Dopamine D3 Receptor (D3R) Ligand Promiscuity across Highly Conserved Aminergic G-Protein-Coupled Receptors (GPCRs)

Autor: Chia-Ju Hsieh, Chi-Chang Weng, Robert R. Luedtke, John Karanicolas, Shipra Malhotra, Daniel A. Jacome, Robert H. Mach, Kuiying Xu, Suzy A. Griffin, Kristoffer Sahlholm, Michelle Taylor, Sean W. Reilly, Christopher Parry, Nathan Kirschner, Aladdin Riad
Rok vydání: 2019
Předmět:
Zdroj: Journal of Medicinal Chemistry. 62:5132-5147
ISSN: 1520-4804
0022-2623
Popis: Previously, we reported a 3-(2-methoxyphenyl)-9-(3-((4-methyl-5-phenyl-4 H-1,2,4-triazol-3-yl)thio)propyl)-3,9-diazaspiro[5.5]undecane (1) compound with excellent dopamine D3 receptor (D3R) affinity (D3R Ki = 12.0 nM) and selectivity (D2R/D3R ratio = 905). Herein, we present derivatives of 1 with comparable D3R affinity (32, D3R Ki = 3.2 nM, D2R/D3R ratio = 60) and selectivity (30, D3R Ki = 21.0 nM, D2R/D3R ratio = 934). Fragmentation of 1 revealed orthosteric fragment 5a to express an unusually low D3R affinity ( Ki = 2.7 μM). Compared to piperazine congener 31, which retains a high-affinity orthosteric fragment (5d, D3R Ki = 23.9 nM), 1 was found to be more selective for the D3R among D1- and D2-like receptors and exhibited negligible off-target interactions at serotoninergic and adrenergic G-protein-coupled receptors (GPCRs), common off-target sites for piperazine-containing D3R scaffolds. This study provides a unique rationale for implementing weakly potent orthosteric fragments into D3R ligand systems to minimize drug promiscuity at other aminergic GPCR sites.
Databáze: OpenAIRE