RESUMO
In this manuscript, we report a series of chiral 6-azaspiro[2.5]octanes and related spirocycles as highly potent and selective antagonists of the muscarinic acetylcholine receptor subtype 4 (mAChR4). Chiral separation and subsequent X-ray crystallographic analysis of early generation analogs revealed the R enantiomer to possess excellent human and rat M4 potency, and further structure-activity relationship (SAR) studies on this chiral scaffold led to the discovery of VU6015241 (compound 19). Compound 19 is characterized by high M4 potency and selectivity across multiple species, excellent aqueous solubility, and moderate brain exposure in rodents after intraperitoneal administration.
Assuntos
Antagonistas Muscarínicos/farmacologia , Receptor Muscarínico M4/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Antagonistas Muscarínicos/síntese química , Antagonistas Muscarínicos/química , Receptor Muscarínico M4/metabolismo , Relação Estrutura-AtividadeRESUMO
This Letter details our efforts to develop novel tricyclic M4 PAM scaffolds with improved pharmacological properties. This endeavor involved a "tie-back" strategy to replace the 3-amino-4,6-dimethylthieno[2,3-b]pyridine-2-carboxamide core which lead to the discovery of two novel tricyclic cores: a 7,9-dimethylpyrido[3',2':4,5]thieno[3,2-d]pyrimidine core and 2,4-dimethylthieno[2,3-b:5,4-c']dipyridine core. Both tricyclic cores displayed low nanomolar potency against the human M4 receptor.
Assuntos
Descoberta de Drogas , Pirimidinas/farmacologia , Receptor Muscarínico M4/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Pirimidinas/síntese química , Pirimidinas/química , Receptor Muscarínico M4/metabolismo , Relação Estrutura-AtividadeRESUMO
This Letter details our efforts to develop new M4 PAM scaffolds with improved pharmacological properties. This endeavor involved replacing the 3,4-dimethylpyridazine core with two novel cores: a 2,3-dimethyl-2H-indazole-5-carboxamide core or a 1-methyl-1H-benzo[d][1,2,3]triazole-6-carboxamide core. Due to shallow SAR, these cores were further evolved into two unique tricyclic cores: an 8,9-dimethyl-8H-pyrazolo[3,4-h]quinazoline core and an 1-methyl-1H-[1,2,3]triazolo[4,5-h]quinazoline core. Both tricyclic cores displayed low nanomolar potency against both human and rat M4.
Assuntos
Piridazinas/química , Quinazolinas/química , Receptor Muscarínico M4/química , Triazóis/química , Regulação Alostérica , Animais , Desenho de Fármacos , Meia-Vida , Humanos , Concentração Inibidora 50 , Piridazinas/metabolismo , Piridazinas/farmacocinética , Quinazolinas/metabolismo , Quinazolinas/farmacocinética , Ratos , Receptor Muscarínico M4/metabolismo , Relação Estrutura-Atividade , Triazóis/metabolismo , Triazóis/farmacocinéticaRESUMO
This Letter details our efforts to discover structurally unique M4 PAMs containing 5,6-heteroaryl ring systems. In an attempt to improve the DMPK profiles of the 2,3-dimethyl-2H-indazole-5-carboxamide and 1-methyl-1H-benzo[d][1,2,3]triazole-6-carboxamide cores, we investigated a plethora of core replacements. This exercise identified a novel 2,3-dimethylimidazo[1,2-a]pyrazine-6-carboxamide core that provided improved M4 PAM activity and CNS penetration.
Assuntos
Imidazóis/química , Pirazinas/química , Receptor Muscarínico M4/química , Regulação Alostérica , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Imidazóis/metabolismo , Cinética , Ligação Proteica , Pirazinas/metabolismo , Receptor Muscarínico M4/metabolismo , Relação Estrutura-AtividadeRESUMO
The 1,2,3-triazole has been successfully utilized as an amide bioisostere in multiple therapeutic contexts. Based on this precedent, triazole analogues derived from VX-809 and VX-770, prominent amide-containing modulators of the cystic fibrosis transmembrane conductance regulator (CFTR), were synthesized and evaluated for CFTR modulation. Triazole 11, derived from VX-809, displayed markedly reduced efficacy in F508del-CFTR correction in cellular TECC assays in comparison to VX-809. Surprisingly, triazole analogues derived from potentiator VX-770 displayed no potentiation of F508del, G551D, or WT-CFTR in cellular Ussing chamber assays. However, patch clamp analysis revealed that triazole 60 potentiates WT-CFTR similarly to VX-770. The efficacy of 60 in the cell-free patch clamp experiment suggests that the loss of activity in the cellular assay could be due to the inability of VX-770 triazole derivatives to reach the CFTR binding site. Moreover, in addition to the negative impact on biological activity, triazoles in both structural classes displayed decreased metabolic stability in human microsomes relative to the analogous amides. In contrast to the many studies that demonstrate the advantages of using the 1,2,3-triazole, these findings highlight the negative impacts that can arise from replacement of the amide with the triazole and suggest that caution is warranted when considering use of the 1,2,3-triazole as an amide bioisostere.
RESUMO
This letter describes a focused, multi-dimensional optimization campaign around BL-1249, a fenamate class non-steroidal anti-inflammatory and a known activator of the K2P potassium channels TREK-1 (K2P2.1) and TREK-2 (K2P10.1). While BL-1249 has been widely profiled in vitro as a dual TREK-1/2 activator, poor physicochemical and DMPK properties have precluded a deeper understanding of the therapeutic potential of these key K2P channels across a broad spectrum of peripheral and central human disease. Here, we report multi-dimensional SAR that led to a novel TREK-1/2 dual activator chemotype, exemplified by ONO-2960632/VU6011992, with improved DMPK properties, representing a new lead for further optimization towards robust in vivo tool compounds.
Assuntos
Canais de Potássio de Domínios Poros em Tandem/metabolismo , Tetra-Hidronaftalenos/uso terapêutico , Tetrazóis/uso terapêutico , Humanos , Tetra-Hidronaftalenos/farmacologia , Tetrazóis/farmacologiaRESUMO
This letter describes a focused exercise to explore the role of the ß-amino carboxamide moiety found in all of the first generation M4 PAMs and question if the NH2 group served solely to stabilize an intramolecular hydrogen bond (IMHB) and enforce planarity. To address this issue (and to potentially find a substitute for the ß-amino carboxamide that engendered P-gp and contributed to solubility liabilities), we removed the NH2, generating des-amino congeners and surveyed other functional groups in the ß-position. These modifications led to weak M4 PAMs with poor DMPK properties. Cyclization of the ß-amino carboxamide moiety by virtue of a pyrazole ring re-enforced the IMHB, led to potent (and patented) M4 PAMs, many as potent as the classical bicyclic ß-amino carboxamide analogs, but with significant CYP1A2 inhibition. Overall, this exercise indicated that the ß-amino carboxamide moiety most likely facilitates an IMHB, and is essential for M4 PAM activity within classical bicyclic M4 PAM scaffolds.
Assuntos
Amidas/farmacologia , Receptor Muscarínico M4/antagonistas & inibidores , Regulação Alostérica/efeitos dos fármacos , Amidas/síntese química , Amidas/química , Relação Dose-Resposta a Droga , Humanos , Ligação de Hidrogênio , Ligantes , Estrutura Molecular , Receptor Muscarínico M4/metabolismo , Relação Estrutura-AtividadeRESUMO
This Letter details our efforts to replace the 2,4-dimethylquinoline carboxamide core of our previous M4 PAM series, which suffered from high predicted hepatic clearance and protein binding. A scaffold hopping exercise identified a novel 3,4-dimethylcinnoline carboxamide core that provided good M4 PAM activity and improved clearance and protein binding profiles.
Assuntos
Receptor Muscarínico M4/química , Regulação Alostérica , Amidas/química , Azetidinas/química , Benzeno/química , Estrutura Molecular , Ligação Proteica , Pirazinas/química , Piridinas/química , Pirimidinas/química , Relação Estrutura-AtividadeRESUMO
This letter describes progress towards an M4 PAM preclinical candidate that resulted in the discovery of VU6005806/AZN-00016130. While the thieno[2,3-c]pyridazine core has been a consistent feature of key M4 PAMs, no work had previously been reported with respect to alternate functionality at the C3 position of the pyridazine ring. Here, we detail new chemistry and analogs that explored this region, and quickly led to VU6005806/AZN-00016130, which was profiled as a putative candidate. While, the ß-amino carboxamide moiety engendered solubility limited absorption in higher species precluding advancement (or requiring extensive pharmaceutical sciences formulation), VU6005806/AZN-00016130 represents a new, high quality preclinical in vivo probe.
Assuntos
Regulação Alostérica/imunologia , Receptor Muscarínico M4/imunologia , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
This letter describes progress towards an M4 PAM preclinical candidate inspired by an unexpected aldehyde oxidase (AO) metabolite of a novel, CNS penetrant thieno[2,3-c]pyridine core to an equipotent, non-CNS penetrant thieno[2,3-c]pyrdin-7(6H)-one core. Medicinal chemistry design efforts yielded two novel tricyclic cores that enhanced M4 PAM potency, regained CNS penetration, displayed favorable DMPK properties and afforded robust in vivo efficacy in reversing amphetamine-induced hyperlocomotion in rats.
Assuntos
Aldeído Oxidase/metabolismo , Miotonia Congênita/metabolismo , Receptor Muscarínico M4/metabolismo , Animais , Descoberta de Drogas , Humanos , Ratos , Relação Estrutura-AtividadeRESUMO
Rett syndrome (RS) is a neurodevelopmental disorder that shares many symptomatic and pathological commonalities with idiopathic autism. Alterations in protein synthesis-dependent synaptic plasticity (PSDSP) are a hallmark of a number of syndromic forms of autism; in the present work, we explore the consequences of disruption and rescue of PSDSP in a mouse model of RS. We report that expression of a key regulator of synaptic protein synthesis, the metabotropic glutamate receptor 5 (mGlu5) protein, is significantly reduced in both the brains of RS model mice and in the motor cortex of human RS autopsy samples. Furthermore, we demonstrate that reduced mGlu5 expression correlates with attenuated DHPG-induced long-term depression in the hippocampus of RS model mice, and that administration of a novel mGlu5 positive allosteric modulator (PAM), termed VU0462807, can rescue synaptic plasticity defects. Additionally, treatment of Mecp2-deficient mice with VU0462807 improves motor performance (open-field behavior and gait dynamics), corrects repetitive clasping behavior, as well as normalizes cued fear-conditioning defects. Importantly, due to the rationale drug discovery approach used in its development, our novel mGlu5 PAM improves RS phenotypes and synaptic plasticity defects without evoking the overt adverse effects commonly associated with potentiation of mGlu5 signaling (i.e. seizures), or affecting cardiorespiratory defects in RS model mice. These findings provide strong support for the continued development of mGlu5 PAMs as potential therapeutic agents for use in RS, and, more broadly, for utility in idiopathic autism.
Assuntos
Transtorno Autístico/genética , Receptor de Glutamato Metabotrópico 5/genética , Síndrome de Rett/genética , Convulsões/genética , Adulto , Regulação Alostérica/genética , Animais , Transtorno Autístico/tratamento farmacológico , Transtorno Autístico/patologia , Autopsia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Humanos , Masculino , Proteína 2 de Ligação a Metil-CpG/genética , Camundongos , Camundongos Knockout , Córtex Motor/efeitos dos fármacos , Córtex Motor/patologia , Plasticidade Neuronal/efeitos dos fármacos , Pirazóis/administração & dosagem , Pirimidinonas/administração & dosagem , Receptor de Glutamato Metabotrópico 5/biossíntese , Síndrome de Rett/tratamento farmacológico , Síndrome de Rett/patologia , Convulsões/tratamento farmacológico , Convulsões/patologia , Transdução de Sinais/efeitos dos fármacos , Adulto JovemRESUMO
Allosteric modulation of GPCRs has initiated a new era of basic and translational discovery, filled with therapeutic promise yet fraught with caveats. Allosteric ligands stabilize unique conformations of the GPCR that afford fundamentally new receptors, capable of novel pharmacology, unprecedented subtype selectivity, and unique signal bias. This review provides a comprehensive overview of the basics of GPCR allosteric pharmacology, medicinal chemistry, drug metabolism, and validated approaches to address each of the major challenges and caveats. Then, the review narrows focus to highlight recent advances in the discovery of allosteric ligands for metabotropic glutamate receptor subtypes 1-5 and 7 (mGlu1-5,7) highlighting key concepts ("molecular switches", signal bias, heterodimers) and practical solutions to enable the development of tool compounds and clinical candidates. The review closes with a section on late-breaking new advances with allosteric ligands for other GPCRs and emerging data for endogenous allosteric modulators.
Assuntos
Receptores Acoplados a Proteínas G/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Regulação Alostérica , Desenho de Fármacos , Humanos , Cinética , Ligantes , Receptores Acoplados a Proteínas G/química , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/genética , Relação Estrutura-AtividadeRESUMO
Mutations that lead to Huntington's disease (HD) result in increased transmission at glutamatergic corticostriatal synapses at early presymptomatic stages that have been postulated to set the stage for pathological changes and symptoms that are observed at later ages. Based on this, pharmacological interventions that reverse excessive corticostriatal transmission may provide a novel approach for reducing early physiological changes and motor symptoms observed in HD. We report that activation of the M4 subtype of muscarinic acetylcholine receptor reduces transmission at corticostriatal synapses and that this effect is dramatically enhanced in presymptomatic YAC128 HD and BACHD relative to wild-type mice. Furthermore, chronic administration of a novel highly selective M4 positive allosteric modulator (PAM) beginning at presymptomatic ages improves motor and synaptic deficits in 5-mo-old YAC128 mice. These data raise the exciting possibility that selective M4 PAMs could provide a therapeutic strategy for the treatment of HD.
Assuntos
Regulação Alostérica/fisiologia , Ácido Glutâmico/metabolismo , Doença de Huntington/tratamento farmacológico , Receptor Muscarínico M4/fisiologia , Transmissão Sináptica/fisiologia , Animais , Encéfalo/metabolismo , Fluorescência , Doença de Huntington/fisiopatologia , Imuno-Histoquímica , Camundongos , Camundongos Mutantes , Piridazinas/farmacologia , Piridazinas/uso terapêutico , Teste de Desempenho do Rota-Rod , Transmissão Sináptica/efeitos dos fármacos , Tiofenos/farmacologia , Tiofenos/uso terapêuticoRESUMO
This letter describes the synthesis and structure activity relationship (SAR) studies of structurally novel M4 antagonists, based on a 4,6-disubstituted core, identified from a high-throughput screening campaign. A multi-dimensional optimization effort enhanced potency at both human and rat M4 (IC50s<300nM), with no substantial species differences noted. Moreover, CNS penetration proved attractive for this series (brain:plasma Kp,uu=0.87), while other DMPK attributes were addressed in the course of the optimization effort, providing low in vivo clearance in rat (CLp=5.37mL/min/kg). Surprisingly, this series displayed pan-muscarinic antagonist activity across M1-5, despite the absence of the prototypical basic or quaternary amine moiety, thus offering a new chemotype from which to develop a next generation of pan-muscarinic antagonist agents.
Assuntos
Antagonistas Muscarínicos/síntese química , Pirimidinas/química , Receptor Muscarínico M4/antagonistas & inibidores , Animais , Encéfalo/metabolismo , Humanos , Concentração Inibidora 50 , Antagonistas Muscarínicos/química , Antagonistas Muscarínicos/farmacocinética , Ligação Proteica , Pirimidinas/síntese química , Pirimidinas/farmacocinética , Ratos , Receptor Muscarínico M4/metabolismo , Receptores Muscarínicos/química , Receptores Muscarínicos/genética , Receptores Muscarínicos/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Relação Estrutura-AtividadeRESUMO
This letter describes the continued optimization of M5 NAM ML375 (VU0483253). While a valuable in vivo tool compound, ML375has an excessively long elimination half-life in rat (t1/2=80h), which can be problematic in certain rodent addiction paradigms (e.g., reinstatement). Thus, we required an M5 NAM of comparable potency to ML375, but with a rat t1/2 of less than 4h. Steep SAR plagued this chemotype, and here we detail aniline replacements that offered some improvements over ML375, but failed to advance. Ultimately, incorporation of a single methyl group to the 9b-phenyl ring acted as a metabolic shunt, providing (S)-11 (VU6008667), an equipotent M5 NAM, with high CNS penetration, excellent selectivity versus M1-4 and the desired short half-life (t1/2=2.3h) in rat.
Assuntos
Sistema Nervoso Central/metabolismo , Antagonistas Muscarínicos/farmacologia , Receptor Muscarínico M5/efeitos dos fármacos , Animais , Meia-Vida , Antagonistas Muscarínicos/farmacocinética , RatosRESUMO
This letter describes the synthesis and structure activity relationship (SAR) studies of structurally novel M4 antagonists, based on a 3-(4-aryl/heteroarylsulfonyl)piperazin-1-yl)-6-(piperidin-1-yl)pyridazine core, identified from a high-throughput screening campaign. A multi-dimensional optimization effort enhanced potency at human M4 (hM4 IC50s<200nM), with only moderate species differences noted, and with enantioselective inhibition. Moreover, CNS penetration proved attractive for this series (rat brain:plasma Kp=2.1, Kp,uu=1.1). Despite the absence of the prototypical mAChR antagonist basic or quaternary amine moiety, this series displayed pan-muscarinic antagonist activity across M1-5 (with 9- to 16-fold functional selectivity at best). This series further expands the chemical diversity of mAChR antagonists.
Assuntos
Encéfalo/metabolismo , Antagonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacocinética , Piridazinas/farmacologia , Piridazinas/farmacocinética , Receptor Muscarínico M4/antagonistas & inibidores , Animais , Encéfalo/efeitos dos fármacos , Células CHO , Cricetulus , Humanos , Antagonistas Muscarínicos/química , Piperazina , Piperazinas/química , Piperazinas/farmacocinética , Piperazinas/farmacologia , Piridazinas/química , Ratos , Receptor Muscarínico M4/metabolismo , Relação Estrutura-AtividadeRESUMO
This Letter details the discovery and subsequent optimization of a novel M4 PAM scaffold based on an 6-fluoro-4-(piperidin-1-yl)quinoline-3-carbonitrile core, which represents a distinct departure from the classical M4 PAM chemotypes. Optimized compounds in this series demonstrated improved M4 PAM potency on both human and rat M4 (4 to 5-fold relative to HTS hit), and displayed attractive physicochemical and DMPK profiles, including good CNS penetration (rat brain:plasma Kp=5.3, Kp,uu=2.4; MDCK-MDR1 (P-gp) ER=1.1).
Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Descoberta de Drogas , Piperidinas/farmacologia , Quinolinas/farmacologia , Receptor Muscarínico M4/antagonistas & inibidores , Animais , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Piperidinas/síntese química , Piperidinas/química , Quinolinas/síntese química , Quinolinas/química , Ratos , Relação Estrutura-AtividadeRESUMO
This Letter details our efforts to replace the 3-amino moiety, an essential pharmacophore for M4 PAM activity in most M4 PAMs to date, within the thieno[2,3-b]pyridine core, as the ß-amino carboxamide motif has been shown to engender poor solubility, varying degrees of P-gp efflux and represents a structural alert. A scaffold hopping exercise identified a novel 2,4-dimethylquinoline carboxamide core that provided M4 PAM activity and good CNS penetration without an amino moiety. In addition, MacMillan photoredox catalysis chemistry was essential for construction of the 2,4-dimethylquinoline core.
Assuntos
Amidas/química , Receptor Muscarínico M4/metabolismo , Regulação Alostérica , Amidas/síntese química , Amidas/farmacocinética , Animais , Encéfalo/metabolismo , Avaliação Pré-Clínica de Medicamentos , Meia-Vida , Ligação Proteica , Piridinas/química , Ratos , Ratos Sprague-Dawley , Receptor Muscarínico M4/química , Relação Estrutura-AtividadeRESUMO
This letter details the continued chemical optimization of a novel series of M4 positive allosteric modulators (PAMs) based on a 5-amino-thieno[2,3-c]pyridazine core by incorporating a 3-amino azetidine amide moiety. The analogs described within this work represent the most potent M4 PAMs reported for this series to date. The SAR to address potency, clearance, subtype selectivity, CNS exposure, and P-gp efflux are described. This work culminated in the discovery of VU6000918, which demonstrated robust efficacy in a rat amphetamine-induced hyperlocomotion reversal model at a minimum efficacious dose of 0.3mg/kg.
Assuntos
Amidas/farmacologia , Azetidinas/farmacologia , Receptor Muscarínico M4/antagonistas & inibidores , Regulação Alostérica/efeitos dos fármacos , Amidas/síntese química , Amidas/química , Animais , Azetidinas/síntese química , Azetidinas/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Ratos , Relação Estrutura-AtividadeRESUMO
This letter describes the chemical optimization of a novel series of M4 positive allosteric modulators (PAMs) based on a 5-amino-thieno[2,3-c]pyridazine core, developed via iterative parallel synthesis, and culminating in the highly utilized rodent in vivo tool compound, VU0467154 (5). This is the first report of the optimization campaign (SAR and DMPK profiling) that led to the discovery of VU0467154, and details all of the challenges faced in allosteric modulator programs (steep SAR, species differences in PAM pharmacology and subtle structural changes affecting CNS penetration).