Discovery of 1,5-Disubstituted Pyridones: A New Class of Positive Allosteric Modulators of the Metabotropic Glutamate 2 Receptor (original) (raw)
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We previously reported the discovery of 4-aryl-substituted pyridones with mGlu2 PAM activity starting from the HTS hit 5. In this article, we describe a different exploration from 5 that led to the discovery of a novel subseries of phenylpiperidine-substituted pyridones. The optimization strategy involved the introduction of different spacers between the pyridone core and the phenyl ring of 5. The fine tuning of metabolism and hERG followed by differentiation of advanced leads that were identified on the basis of PK profiles and in vivo potency converged on lead compound 36 (JNJ-40411813). Full in vitro and in vivo profiles indicate that 36 displayed an optimal interplay between potency, selectivity, favorable ADMET/PK and cardiovascular safety profile, and central EEG activity. Compound 36 has been investigated in the clinic for schizophrenia and anxious depression disorders.
The discovery and characterization of compound 48, a selective and in vivo active mGlu2 receptor positive allosteric modulator (PAM), are described. A key to the discovery was the rational exploration of the initial HTS hit 13 guided by an overlay model built with reported mGlu2 receptor PAM chemotypes. The initial weak in vitro activity of the hit 13 was quickly improved, although compounds still had suboptimal druglike properties. Subsequent modulation of the physicochemical properties resulted in compounds having a more balanced profile, combining good potency and in vivo pharmacokinetic properties. Final refinement by addressing cardiovascular safety liabilities led to the discovery of compound 48. Besides good potency, selectivity, and ADME properties, compound 48 displayed robust in vivo activity in a sleep−wake electroencephalogram (sw-EEG) assay consistent with mGlu2 receptor activation, in accordance with previous work from our laboratories.
ACS Medicinal Chemistry Letters, 2012
Negative allosteric modulators (NAMs) of metabotropic glutamate receptor subtype 5 (mGluR5) have shown promising results in preclinical models for anxiety and drug abuse. Here, we describe a series of aryl-substituted alkynyl analogues of the prototypic mGluR5 NAM 2-methyl-6-(phenylethynyl)pyridine (MPEP, 1). Displacement of [ 3 H]1 binding in rat brain membranes showed that several of these novel compounds displayed high affinity binding (K i < 10 nM) for mGluR5, with up to a 24-fold increase in affinity over 1. Replacements of the 2-position Me on the pyridyl ring of 1 along with various 3′-CN, 5′-substitutions were generally well tolerated. All of the active analogues in this series had cLog P values in the 2−5 range and displayed inverse agonist characteristics in an ELISA-based assay of G q α-mediated IP3 production. Compounds 7i and 7j produced in vivo effects in mouse models of anxiety-like behaviors more potently than 1 or 3-3-((2methyl-4-thiazolyl)ethynyl)pyridine (MTEP, 2), supporting their utility as in vivo tools.
Molecular pharmacology, 2007
Exciting advances have been made in the discovery of selective positive allosteric modulators of the metabotropic glutamate receptor (mGluR) mGluR5. These compounds may provide a novel approach that could be useful in the treatment of certain central nervous system disorders. However, because of their low potencies, previously described mGluR5 potentiators are not useful for functional studies in native preparations. In addition, binding sites at which these compounds act have not been identified. It has been suggested that two allosteric potentiators, 3,3'-difluorobenzaldazine and 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB), act by binding to the same allosteric site as the negative allosteric modulators of mGluR5 such as 2-methyl-6-(phenylethynyl)pyridine (MPEP). However, another mGluR5 potentiator, N-{4-chloro-2-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)m-ethyl]phenyl}-2-hydroxybenzamide, does not bind to this site, bringing this hypothesis into question. We have...
ACS Medicinal Chemistry Letters, 2016
The metabotropic glutamate receptor 5 (mGluR5) is an attractive target for the treatment of schizophrenia due to its role in regulating glutamatergic signaling in association with the N-methyl-D-aspartate receptor (NMDAR). We describe the synthesis of 1H-pyrazolo[3,4-b]pyridines and their utility as mGluR5 positive allosteric modulators (PAMs) without inherent agonist activity. A facile and convergent synthetic route provided access to a structurally diverse set of analogues that contain neither the aryl-acetylene-aryl nor aryl-methyleneoxy-aryl elements, the predominant structural motifs described in the literature. Binding studies suggest that members of our new chemotype do not engage the receptor at the MPEP and CPPHA mGluR5 allosteric sites. SAR studies culminated in the first non-MPEP site PAM, 1H-pyrazolo[3,4-b]pyridine 31 (BMT-145027), to improve cognition in a preclinical rodent model of learning and memory.
Bioorganic & Medicinal Chemistry Letters, 2011
Based on SAR in the alkyne class of mGlu5 receptor negative allosteric modulators and a set of amide-based positive allosteric modulators, optimized substitution of the aryl 'b' ring was used to create substituted N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamides. Results from an mGlu5 receptor functional assay, using calcium fluorescence, revealed varying efficacies and potencies that provide evidence that subtle changes in compounds within a close structural class can have marked effects on functional activity including switches in modes of efficacy (i.e. negative to positive allosteric modulation). 1 This manuscript is dedicated to Professor James M. Cook on the occasion of his 65 th birthday.
Neuropharmacology, 2017
The metabotropic glutamate receptor 2 (mGlu 2) plays an important role in the presynaptic control of glutamate release and several mGlu 2 positive allosteric modulators (PAMs) have been under assessment for their potential as antipsychotics. The binding mode of mGlu 2 PAMs is better characterized in functional terms while few data are available on the relationship between allosteric and orthosteric binding sites. Pharmacological studies characterizing binding and effects of two different chemical series of mGlu 2 PAMs are therefore carried out here using the radiolabeled mGlu 2 agonist 3 [H]-LY354740 and mGlu 2 PAM 3 [H]-2,2,2-TEMPS. A multidimensional approach to the PAM mechanism of action shows that mGlu 2 PAMs increase the affinity of 3 [H]-LY354740 for the orthosteric site of mGlu2 as well as the number of 3 [H]-LY354740 binding sites. 3 [H]-2,2,2-TEMPS binding is also enhanced by the presence of LY354740. New residues in the allosteric rat mGlu2 binding pocket are identified to be crucial for the PAMs ligand binding, among these Tyr 3.40 and Asn 5.46. Also of remark, in the described experimental conditions S731A (Ser 5.42) residue is important only for the mGlu 2 PAM LY487379 and not for the compound PAM-1: an example of the structural differences among these mGlu 2 PAMs. This study provides a summary of the information generated in the past decade on mGlu 2 PAMs adding a detailed molecular investigation of PAM binding mode. Differences among mGlu 2 PAM compounds are discussed as well as the mGlu2 regions interacting with mGlu 2 PAM and NAM agents and residues driving mGlu2 PAM selectivity.
Journal of Medicinal Chemistry, 2003
This report describes recently discovered novel allosteric modulators of metabotropic glutamate2 (mGlu2) receptors. These pyridylmethylsulfonamides (e.g., 3) potentiate glutamate, shifting agonist potency by 2-fold. This effect was specific for mGlu2 (vs mGlu1,3-8 receptors). Also, 3 failed to potentiate a chimeric mGlu2/1 receptor, demonstrating the mGlu2 transmembrane region's critical involvement. In a fearpotentiated startle model, 3 showed anxiolytic activity that was prevented by mGlu2/3 antagonist pretreatment. Thus, these pyridylmethylsulfonamides represent the first mGlu2 receptor potentiators discovered.