RESUMO
Riboswitches are non-coding RNA structures located in messenger RNAs that bind endogenous ligands, such as a specific metabolite or ion, to regulate gene expression. As such, riboswitches serve as a novel, yet largely unexploited, class of emerging drug targets. Demonstrating this potential, however, has proven difficult and is restricted to structurally similar antimetabolites and semi-synthetic analogues of their cognate ligand, thus greatly restricting the chemical space and selectivity sought for such inhibitors. Here we report the discovery and characterization of ribocil, a highly selective chemical modulator of bacterial riboflavin riboswitches, which was identified in a phenotypic screen and acts as a structurally distinct synthetic mimic of the natural ligand, flavin mononucleotide, to repress riboswitch-mediated ribB gene expression and inhibit bacterial cell growth. Our findings indicate that non-coding RNA structural elements may be more broadly targeted by synthetic small molecules than previously expected.
Assuntos
Pirimidinas/química , Pirimidinas/farmacologia , RNA Bacteriano/química , RNA Bacteriano/efeitos dos fármacos , Riboswitch/efeitos dos fármacos , Animais , Aptâmeros de Nucleotídeos/química , Bactérias/citologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Sequência de Bases , Cristalografia por Raios X , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Feminino , Mononucleotídeo de Flavina/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico/genética , Transferases Intramoleculares/genética , Ligantes , Camundongos , Camundongos Endogâmicos DBA , Modelos Moleculares , Dados de Sequência Molecular , Pirimidinas/isolamento & purificação , Pirimidinas/uso terapêutico , RNA Bacteriano/genética , Reprodutibilidade dos Testes , Riboflavina/biossíntese , Riboswitch/genética , Especificidade por SubstratoRESUMO
The outer membrane (OM) of Gram-negative bacteria forms a robust permeability barrier that blocks entry of toxins and antibiotics. Most OM proteins (OMPs) assume a ß-barrel fold, and some form aqueous channels for nutrient uptake and efflux of intracellular toxins. The Bam machine catalyzes rapid folding and assembly of OMPs. Fidelity of OMP biogenesis is monitored by the σE stress response. When OMP folding defects arise, the proteases DegS and RseP act sequentially to liberate σE into the cytosol, enabling it to activate transcription of the stress regulon. Here, we identify batimastat as a selective inhibitor of RseP that causes a lethal decrease in σE activity in Escherichia coli, and we further identify RseP mutants that are insensitive to inhibition and confer resistance. Remarkably, batimastat treatment allows the capture of elusive intermediates in the OMP biogenesis pathway and offers opportunities to better understand the underlying basis for σE essentiality.
Assuntos
Proteínas da Membrana Bacteriana Externa , Endopeptidases , Proteínas de Escherichia coli , Escherichia coli , Proteínas de Membrana , Desdobramento de Proteína , Fatores de Transcrição , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Endopeptidases/genética , Endopeptidases/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Bruton's tyrosine kinase (BTK) is a Tec family kinase with a well-defined role in the B cell receptor (BCR) pathway. It has become an attractive kinase target for selective B cell inhibition, and for the treatment of B cell related diseases. Many BTK inhibitors have been discovered for the treatment of cancer and rheumatoid arthritis, including a series of BTK inhibitors based on 8-amino-imidazo[1,5-a]pyrazine we recently reported. The X-ray crystal structures of BTK with inhibitors were also published, which provided great help for the SAR design. Here we report our SAR work introducing ring constraints for the 3-position piperidine amides on the BTK inhibitors based on 8-amino-imidazo[1,5-a]pyrazine. This modification improved the potency in BTK inhibitions, as well as the PK profile and the off-target selectivity. The dose-dependent efficacy of two BTK inhibitors was observed in the rat collagen induced arthritis (CIA) model.
Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Imidazóis/química , Inibidores de Proteínas Quinases/química , Pirazinas/química , Tirosina Quinase da Agamaglobulinemia/metabolismo , Animais , Artrite Experimental/tratamento farmacológico , Sítios de Ligação , Compostos Bicíclicos com Pontes/química , Cristalografia por Raios X , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Meia-Vida , Humanos , Imidazóis/metabolismo , Imidazóis/uso terapêutico , Simulação de Dinâmica Molecular , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Pirazinas/metabolismo , Pirazinas/uso terapêutico , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismoRESUMO
New synthetic methods were developed for the preparation of 2,3,6-trisubstituted 1-oxo-1,2-dihydroisoquinolines as CRTh2 antagonists. The isoquinolinone core could be constructed before the introduction of substitution groups or synthesized through a catalytic intramolecular cyclization reaction with desired substitution groups properly installed. These synthetic strategies have helped to accelerate the SAR development of this series, and potent lead compounds were identified in both the CRTh2 receptor binding assay and the CD11b biomarker assay.
Assuntos
Isoquinolinas/farmacologia , Receptores Imunológicos/antagonistas & inibidores , Receptores de Prostaglandina/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Isoquinolinas/síntese química , Isoquinolinas/química , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
8-Amino-imidazo[1,5-a]pyrazine-based Bruton's tyrosine kinase (BTK) inhibitors, such as 6, exhibited potent inhibition of BTK but required improvements in both kinase and hERG selectivity (Liu et al., 2016; Gao et al., 2017). In an effort to maintain the inhibitory activity of these analogs and improve their selectivity profiles, we carried out SAR exploration of groups at the 3-position of pyrazine compound 6. This effort led to the discovery of the morpholine group as an optimized pharmacophore. Compounds 13, 23 and 38 displayed excellent BTK potencies, kinase and hERG selectivities, and pharmacokinetic profiles.
Assuntos
Artrite Reumatoide/tratamento farmacológico , Descoberta de Drogas , Imidazóis/farmacologia , Morfolinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Artrite Reumatoide/metabolismo , Relação Dose-Resposta a Droga , Humanos , Imidazóis/síntese química , Imidazóis/química , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Modelos Moleculares , Estrutura Molecular , Morfolinas/síntese química , Morfolinas/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Tirosina Quinases/metabolismo , Relação Estrutura-Atividade , Regulador Transcricional ERG/antagonistas & inibidores , Regulador Transcricional ERG/metabolismoRESUMO
We report the design and synthesis of a series of novel Bruton's Tyrosine Kinase (BTK) inhibitors with a carboxylic acid moiety in the ribose pocket. This series of compounds has demonstrated much improved off-target selectivities including adenosine uptake (AdU) inhibition compared to the piperidine amide series. Optimization of the initial lead compound 4 based on BTK enzyme inhibition, and human peripheral blood mononuclear cell (hPBMC) and human whole blood (hWB) activity led to the discovery of compound 40, with potent BTK inhibition, reduced off target activities, as well as favorable pharmacokinetic profile in both rat and dog.
Assuntos
Ácidos Carboxílicos/farmacologia , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia , Animais , Humanos , RatosRESUMO
Oxabicyclooctane-linked novel bacterial topoisomerase inhibitors (NBTIs) represent a new class of recently described antibacterial agents with broad-spectrum activity. NBTIs dually inhibit the clinically validated bacterial targets DNA gyrase and topoisomerase IV and have been shown to bind distinctly from known classes of antibacterial agents directed against these targets. Herein we report the molecular, cellular, and in vivo characterization of AM-8722 as a representative N-alkylated-1,5-naphthyridone left-hand-side-substituted NBTI. Consistent with its mode of action, macromolecular labeling studies revealed a specific effect of AM-8722 to dose dependently inhibit bacterial DNA synthesis. AM-8722 displayed greater intrinsic enzymatic potency than levofloxacin versus both DNA gyrase and topoisomerase IV from Staphylococcus aureus and Escherichia coli and displayed selectivity against human topoisomerase II. AM-8722 was rapidly bactericidal and exhibited whole-cell activity versus a range of Gram-negative and Gram-positive organisms, with no whole-cell potency shift due to the presence of DNA or human serum. Frequency-of-resistance studies demonstrated an acceptable rate of resistance emergence in vitro at concentrations 16- to 32-fold the MIC. AM-8722 displayed acceptable pharmacokinetic properties and was shown to be efficacious in mouse models of bacterial septicemia. Overall, AM-8722 is a selective and potent NBTI that displays broad-spectrum antimicrobial activity in vitro and in vivo.
Assuntos
Antibacterianos/farmacologia , Ciclo-Octanos/farmacologia , DNA Girase/metabolismo , DNA Topoisomerase IV/antagonistas & inibidores , DNA Topoisomerases Tipo II/metabolismo , Inibidores da Topoisomerase II/farmacologia , Animais , Linhagem Celular , DNA Bacteriano/genética , Cães , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções por Escherichia coli/tratamento farmacológico , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Ratos , Ratos Wistar , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genéticaRESUMO
The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically eroded the efficacy of current ß-lactam antibiotics and created an urgent need for novel treatment options. Using an S. aureus phenotypic screening strategy, we have identified small molecule early stage wall teichoic acid (WTA) pathway-specific inhibitors predicted to be chemically synergistic with ß-lactams. These previously disclosed inhibitors, termed tarocins, demonstrate by genetic and biochemical means inhibition of TarO, the first step in WTA biosynthesis. Tarocins demonstrate potent bactericidal synergy in combination with broad spectrum ß-lactam antibiotics across diverse clinical isolates of methicillin-resistant Staphylococci. The synthesis and structure-activity relationships (SAR) of a tarocin series will be detailed. Tarocins and other WTA inhibitors may provide a rational strategy to develop Gram-positive bactericidal ß-lactam combination agents active against methicillin-resistant Staphylococci.
Assuntos
Antibacterianos/química , Ácidos Teicoicos/metabolismo , beta-Lactamas/antagonistas & inibidores , Antibacterianos/síntese química , Antibacterianos/farmacologia , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Avaliação Pré-Clínica de Medicamentos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , beta-Lactamas/metabolismoRESUMO
A series of benzimidazole analogs have been synthesized to improve the profile of the previous lead compounds tarocin B and 1. The syntheses, structure-activity relationships, and selected biochemical data of these analogs are described. The optimization efforts allowed the identification of 21, a fluoro-substituted benzimidazole, exhibiting potent TarO inhibitory activity and typical profile for a wall teichoic acid (WTA) biosynthesis inhibitor. Compound 21 displayed a potent synergistic and bactericidal effect in combination with imipenem against diverse methicillin-resistant Staphylococci.
Assuntos
Antibacterianos/farmacologia , Benzimidazóis/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Ácidos Teicoicos/antagonistas & inibidores , Animais , Antibacterianos/química , Benzimidazóis/química , Testes de Sensibilidade Microbiana , Ratos , Relação Estrutura-Atividade , Ácidos Teicoicos/biossínteseRESUMO
IRAK4 has been identified as potential therapeutic target for inflammatory and autoimmune diseases. Herein we report the identification and initial SAR studies of a new class of pyrazole containing IRAK4 inhibitors designed to expand chemical diversity and improve off target activity of a previously identified series. These compounds maintain potent IRAK4 activity and desirable ligand efficiency. Rat clearance and a variety of off target activities were also examined, resulting in encouraging data with tractable SAR.
Assuntos
Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Pirazóis/química , Animais , Sítios de Ligação , Cristalografia por Raios X , Meia-Vida , Humanos , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Ligantes , Simulação de Dinâmica Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Estrutura Terciária de Proteína , Pirazóis/metabolismo , Pirazóis/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
Bacterial resistance to antibiotics continues to grow and pose serious challenges, while the discovery rate for new antibiotics declines. Kibdelomycin is a recently discovered natural-product antibiotic that inhibits bacterial growth by inhibiting the bacterial DNA replication enzymes DNA gyrase and topoisomerase IV. It was reported to be a broad-spectrum aerobic Gram-positive agent with selective inhibition of the anaerobic bacterium Clostridium difficile. We have extended the profiling of kibdelomycin by using over 196 strains of Gram-positive and Gram-negative aerobic pathogens recovered from worldwide patient populations. We report the MIC50s, MIC90s, and bactericidal activities of kibdelomycin. We confirm the Gram-positive spectrum and report for the first time that kibdelomycin shows strong activity (MIC90, 0.125 µg/ml) against clinical strains of the Gram-negative nonfermenter Acinetobacter baumannii but only weak activity against Pseudomonas aeruginosa. We confirm that well-characterized resistant strains of Staphylococcus aureus and Streptococcus pneumoniae show no cross-resistance to kibdelomycin and quinolones and coumarin antibiotics. We also show that kibdelomycin is not subject to efflux in Pseudomonas, though it is in Escherichia coli, and it is generally affected by the outer membrane permeability entry barrier in the nonfermenters P. aeruginosa and A. baumannii, which may be addressable by structure-based chemical modification.
Assuntos
Antibacterianos/farmacologia , Pirróis/farmacologia , Pirrolidinonas/farmacologia , Acinetobacter baumannii/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacosRESUMO
IRAK4 plays a key role in TLR/IL-1 signaling. Previous efforts identified a series of aminopyrimidine IRAK4 inhibitors that possess good potency, but modest kinase selectivity. Exploration of substituents at the C-2 and C-5 positions generated compounds that maintained IRAK4 potency and improved kinase selectivity. Additionally, it was found that the pyrimidine core could be replaced with a pyridine and still retain potency and kinase selectivity. The optimization efforts led to compound 26 which had an IRAK4 IC50 of 0.7 nM, an IC50 of 55 nM on THP-1 cells stimulated with LPS, a TLR4 agonist, and greater than 100-fold selectivity versus 96% of a panel of 306 kinases.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , Pirimidinas/síntese química , Pirimidinas/farmacologia , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/farmacologia , Linhagem Celular , Ensaios de Triagem em Larga Escala , Humanos , Lipopolissacarídeos/farmacologia , Relação Estrutura-Atividade , Especificidade por Substrato , Receptor 4 Toll-Like/antagonistas & inibidoresRESUMO
Isoxazoles are frequently used amide isosteres, as shown in the context of discovery of CRTh2 antagonists from amide 1 to isoxazole 2. However, persistent agonism and poor solubility in isoxazole series presented challenges to its further development. Based on the concept of quality by design (QbD), 5,5-disubstituted isoxazolines 3 were introduced. The chirality at 5 position of isoxazolines controlled the switch between two modes of actions, which led to a novel series of pure antagonists. This non-planar motif also conferred a change of shape of these molecules, which avoided flat structures and improved their physical properties.
Assuntos
Amidas/química , Desenho de Fármacos , Isoxazóis/química , Quinazolinonas/química , Receptores Imunológicos/antagonistas & inibidores , Receptores de Prostaglandina/antagonistas & inibidores , Animais , Cães , Meia-Vida , Haplorrinos , Humanos , Isoxazóis/síntese química , Isoxazóis/farmacocinética , Quinazolinonas/síntese química , Quinazolinonas/farmacocinética , Ratos , Ratos Wistar , Receptores Imunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Solubilidade , Relação Estrutura-AtividadeRESUMO
The use of ß-lactam (BL) and ß-lactamase inhibitor combination to overcome BL antibiotic resistance has been validated through clinically approved drug products. However, unmet medical needs still exist for the treatment of infections caused by Gram-negative (GN) bacteria expressing metallo-ß-lactamases. Previously, we reported our effort to discover pan inhibitors of three main families in this class: IMP, VIM, and NDM. Herein, we describe our work to improve the GN coverage spectrum in combination with imipenem and relebactam. This was achieved through structure- and property-based optimization to tackle the GN cell penetration and efflux challenges. A significant discovery was made that inhibition of both VIM alleles, VIM-1 and VIM-2, is essential for broad GN coverage, especially against VIM-producing P. aeruginosa. In addition, pharmacokinetics and nonclinical safety profiles were investigated for select compounds. Key findings from this drug discovery campaign laid the foundation for further lead optimization toward identification of preclinical candidates.
Assuntos
Antibacterianos , Inibidores de beta-Lactamases , Humanos , Inibidores de beta-Lactamases/farmacologia , Inibidores de beta-Lactamases/uso terapêutico , Inibidores de beta-Lactamases/química , Antibacterianos/química , Imipenem/farmacologia , beta-Lactamases , Bactérias Gram-Negativas , Testes de Sensibilidade MicrobianaRESUMO
Structure-activity relationship (SAR) efforts around our initial lead compound 1 led to the identification of potent P2X(7) receptor antagonists with improved pharmacokinetic profiles. These compounds were potent and selective at the P2X(7) receptor in both human and rodent. Compound (entry 31) exhibited oral efficacy in the rat MIA and CCI pain models.
Assuntos
Analgésicos/síntese química , Desenho de Fármacos , Dor , Antagonistas do Receptor Purinérgico P2/síntese química , Administração Oral , Analgésicos/química , Animais , Modelos Animais de Doenças , Humanos , Estrutura Molecular , Dor/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2/química , Ratos , Receptores Purinérgicos P2X7/metabolismo , Relação Estrutura-AtividadeRESUMO
To combat the threat of antibiotic-resistant Gram-negative bacteria, novel agents that circumvent established resistance mechanisms are urgently needed. Our approach was to focus first on identifying bioactive small molecules followed by chemical lead prioritization and target identification. Within this annotated library of bioactives, we identified a small molecule with activity against efflux-deficient Escherichia coli and other sensitized Gram-negatives. Further studies suggested that this compound inhibited DNA replication and selection for resistance identified mutations in a subunit of E. coli DNA gyrase, a type II topoisomerase. Our initial compound demonstrated weak inhibition of DNA gyrase activity while optimized compounds demonstrated significantly improved inhibition of E. coli and Pseudomonas aeruginosa DNA gyrase and caused cleaved complex stabilization, a hallmark of certain bactericidal DNA gyrase inhibitors. Amino acid substitutions conferring resistance to this new class of DNA gyrase inhibitors reside exclusively in the TOPRIM domain of GyrB and are not associated with resistance to the fluoroquinolones, suggesting a novel binding site for a gyrase inhibitor.
Assuntos
Antibacterianos/farmacologia , DNA Girase/metabolismo , Inibidores da Topoisomerase II/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Fluoroquinolonas/farmacologia , Testes de Sensibilidade Microbiana , Domínios Proteicos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologiaRESUMO
We describe our optimization efforts to improve the physicochemical properties, solubility, and off-target profile of 1, an inhibitor of TarO, an early stage enzyme in the biosynthetic pathway for wall teichoic acid (WTA) synthesis. Compound 1 displayed a TarO IC50 of 125 nM in an enzyme assay and possessed very high lipophilicity (clogP = 7.1) with no measurable solubility in PBS buffer. Structure-activity relationship (SAR) studies resulted in a series of compounds with improved lipophilic ligand efficiency (LLE) consistent with the reduction of clogP. From these efforts, analog 9 was selected for our initial in vivo study, which in combination with subefficacious dose of imipenem (IPM) robustly lowered the bacterial burden in a neutropenic Staphylococci murine infection model. Concurrent with our in vivo optimization effort using 9, we further improved LLE as exemplified by a much more druglike analog 26.
Assuntos
Lipídeos/química , Bibliotecas de Moléculas Pequenas , Animais , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Solubilidade , Relação Estrutura-AtividadeRESUMO
The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically eroded the efficacy of current ß-lactam antibiotics and created an urgent need for new treatment options. We report an S. aureus phenotypic screening strategy involving chemical suppression of the growth inhibitory consequences of depleting late-stage wall teichoic acid biosynthesis. This enabled us to identify early-stage pathway-specific inhibitors of wall teichoic acid biosynthesis predicted to be chemically synergistic with ß-lactams. We demonstrated by genetic and biochemical means that each of the new chemical series discovered, herein named tarocin A and tarocin B, inhibited the first step in wall teichoic acid biosynthesis (TarO). Tarocins do not have intrinsic bioactivity but rather demonstrated potent bactericidal synergy in combination with broad-spectrum ß-lactam antibiotics against diverse clinical isolates of methicillin-resistant staphylococci as well as robust efficacy in a murine infection model of MRSA. Tarocins and other inhibitors of wall teichoic acid biosynthesis may provide a rational strategy to develop Gram-positive bactericidal ß-lactam combination agents active against methicillin-resistant staphylococci.
Assuntos
Proteínas de Bactérias/metabolismo , Vias Biossintéticas/efeitos dos fármacos , Parede Celular/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Ácidos Teicoicos/biossíntese , beta-Lactamas/farmacologia , Animais , Parede Celular/efeitos dos fármacos , Dicloxacilina/farmacologia , Dicloxacilina/uso terapêutico , Feminino , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Modelos Moleculares , Fenótipo , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Resultado do TratamentoRESUMO
Bruton's tyrosine kinase (BTK) is a Tec family kinase with a well-defined role in the B cell receptor (BCR) pathway. It has become an attractive kinase target for selective B cell inhibition and for the treatment of B cell related diseases. We report a series of compounds based on 8-amino-imidazo[1,5-a]pyrazine that are potent reversible BTK inhibitors with excellent kinase selectivity. Selectivity is achieved through specific interactions of the ligand with the kinase hinge and driven by aminopyridine hydrogen bondings with Ser538 and Asp539, and by hydrophobic interaction of trifluoropyridine in the back pocket. These interactions are evident in the X-ray crystal structure of the lead compounds 1 and 3 in the complex with the BTK enzyme. Our lead compounds show desirable PK profiles and efficacy in the preclinical rat collagen induced arthritis model.
RESUMO
We report the identification and synthesis of a series of aminopyrimidin-4-one IRAK4 inhibitors. Through high throughput screening, an aminopyrimidine hit was identified and modified via structure enabled design to generate a new, potent, and kinase selective pyrimidin-4-one chemotype. This chemotype is exemplified by compound 16, which has potent IRAK4 inhibition activity (IC50 = 27 nM) and excellent kinase selectivity (>100-fold against 99% of 111 tested kinases), and compound 31, which displays potent IRAK4 activity (IC50 = 93 nM) and good rat bioavailability (F = 42%).