1. Design and synthesis of 1-(1-benzothiophen-7-yl)-1H-pyrazole, a novel series of G protein-coupled receptor 52 (GPR52) agonists
- Author
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Masakuni Kori, Kazuyoshi Aso, Teruki Hamada, Yuji Shimizu, Naoki Ishii, Takashi Nakahata, Toshiya Harasawa, Kazuyuki Tokumaru, Yoshiteru Ito, Masaki Setoh, and Kazunobu Aoyama
- Subjects
Male ,0301 basic medicine ,Agonist ,medicine.drug_class ,Stereochemistry ,Clinical Biochemistry ,Substituent ,Pharmaceutical Science ,Thiophenes ,Pyrazole ,Biochemistry ,Methamphetamine ,Receptors, G-Protein-Coupled ,Mice ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Dopamine receptor D2 ,Drug Discovery ,medicine ,Animals ,Humans ,Structure–activity relationship ,Solubility ,Receptor ,Molecular Biology ,Mice, Inbred ICR ,Dose-Response Relationship, Drug ,Molecular Structure ,Chemistry ,Organic Chemistry ,030104 developmental biology ,Drug Design ,Lipophilicity ,Pyrazoles ,Molecular Medicine ,Locomotion ,030217 neurology & neurosurgery - Abstract
G-protein-coupled receptor 52 (GPR52) is classified as an orphan Gs-coupled G-protein-coupled receptor. GPR52 cancels dopamine D2 receptor signaling and activates dopamine D1/N-methyl-d-aspartate receptors via intracellular cAMP accumulation. Therefore, GPR52 agonists are expected to alleviate symptoms of psychotic disorders. A novel series of 1-(benzothiophen-7-yl)-1H-pyrazole as GPR52 agonists was designed and synthesized based on compound 1b. Compound 1b has been reported by our group as the first orally active GPR52 agonist, but high lipophilicity and poor aqueous solubility still remained as issues for candidate selection. To resolve these issues, replacement of the benzene ring at the 7-positon of compound 1b with heterocylic rings, such as pyrazole and pyridine, was greatly expected to reduce lipophilicity to levels for which calculated logD values were lower than that of compound 1b. While evaluating the pyrazole derivatives, introduction of a methyl substituent at the 3-position of the pyrazole ring led to increased GPR52 agonistic activity. Moreover, additional methyl substituent at the 5-position of the pyrazole and further introduction of hydroxy group to lower logD led to significant improvement of solubility while maintaining the activity. As a result, we identified 3-methyl-5-hydroxymethyl-1H-pyrazole derivative 17 (GPR52 EC50 = 21 nM, Emax = 103%, logD = 2.21, Solubility at pH 6.8 = 21 μg/mL) with potent GPR52 agonistic activity and good solubility compared to compound 1b. Furthermore, this compound 17 dose-dependently suppressed methamphetamine-induced hyperlocomotion in mice.
- Published
- 2018