RESUMO
The discovery of a novel series of pyrrolopyrazines as JAK inhibitors with comparable enzyme and cellular activity to tofacitinib is described. The series was identified using a scaffold hopping approach aided by structure based drug design using principles of intramolecular hydrogen bonding for conformational restriction and targeting specific pockets for modulating kinase activity.
Assuntos
Janus Quinase 3/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/química , Pirróis/química , Desenho de Fármacos , Humanos , Janus Quinase 3/metabolismo , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Fosforilação , Piperidinas/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Relação Estrutura-AtividadeRESUMO
We report the discovery of a novel series of ATP-competitive Janus kinase 3 (JAK3) inhibitors based on the 5H-pyrrolo[2,3-b]pyrazine scaffold. The initial leads in this series, compounds 1a and 1h, showed promising potencies, but a lack of selectivity against other isoforms in the JAK family. Computational and crystallographic analysis suggested that the phenyl ether moiety possessed a favorable vector to achieve selectivity. Exploration of this vector resulted in the identification of 12b and 12d, as potent JAK3 inhibitors, demonstrating improved JAK family and kinase selectivity.
Assuntos
Janus Quinase 3/antagonistas & inibidores , Éteres Fenílicos/química , Inibidores de Proteínas Quinases/química , Piridazinas/química , Pirróis/química , Sítios de Ligação , Domínio Catalítico , Avaliação Pré-Clínica de Medicamentos , Janus Quinase 3/metabolismo , Simulação de Acoplamento Molecular , Éteres Fenílicos/síntese química , Éteres Fenílicos/metabolismo , Ligação Proteica , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Relação Estrutura-AtividadeRESUMO
Using a structure based design approach we have identified a series of indazole substituted pyrrolopyrazines, which are potent inhibitors of JAK3. Intramolecular electronic repulsion was used as a strategy to induce a strong conformational bias within the ligand. Compounds bearing this conformation participated in a favorable hydrophobic interaction with a cysteine residue in the JAK3 binding pocket, which imparted high selectivity versus the kinome and improved selectivity within the JAK family.
Assuntos
Desenho de Fármacos , Janus Quinase 3/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Sítios de Ligação , Cristalografia por Raios X , Interações Hidrofóbicas e Hidrofílicas , Indazóis/química , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 1/metabolismo , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/metabolismo , Janus Quinase 3/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Estrutura Terciária de Proteína , Pirazinas/síntese química , Pirazinas/química , Pirazinas/metabolismo , Relação Estrutura-AtividadeRESUMO
A novel series of indole/indazole-aminopyrimidines was designed and synthesized with an aim to achieve optimal potency and selectivity for the c-Jun kinase family or JNKs. Structure guided design was used to optimize the series resulting in a significant potency improvement. The best compound (17) has IC50 of 3 nM for JNK1 and 20 nM for JNK2, with greater than 40-fold selectivity against other kinases with good physicochemical and pharmacokinetic properties.
Assuntos
Indóis/química , Indóis/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Cristalografia por Raios X , Indazóis/química , Indazóis/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/química , Fosforilação , Relação Estrutura-AtividadeRESUMO
A series of amino-pyrimidines was developed based upon an initial kinase cross-screening hit from a CDK2 program. Kinase profiling and structure-based drug design guided the optimization from the initial 1,2,3-benzotriazole hit to a potent and selective JNK inhibitor, compound 24f (JNK1 and 2 IC(50)=16 and 66 nM, respectively), with bioavailability in rats and suitable for further in vivo pharmacological evaluation.
Assuntos
Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Triazóis/química , Triazóis/farmacologia , Animais , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Modelos Moleculares , Inibidores de Proteínas Quinases/síntese química , Pirimidinas/síntese química , Ratos , Relação Estrutura-Atividade , Triazóis/síntese químicaRESUMO
A novel series of highly selective JNK inhibitors based on the 4-quinolone scaffold was designed and synthesized. Structure based drug design was utilized to guide the compound design as well as improvements in the physicochemical properties of the series. Compound (13c) has an IC(50) of 62/170 nM for JNK1/2, excellent kinase selectivity and impressive efficacy in a rodent asthma model.
Assuntos
4-Quinolonas/farmacologia , Descoberta de Drogas , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , 4-Quinolonas/síntese química , 4-Quinolonas/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-AtividadeRESUMO
Inhibition of spleen tyrosine kinase has attracted much attention as a mechanism for the treatment of cancers and autoimmune diseases such as asthma, rheumatoid arthritis, and systemic lupus erythematous. We report the structure-guided optimization of pyridazine amide spleen tyrosine kinase inhibitors. Early representatives of this scaffold were highly potent and selective but mutagenic in an Ames assay. An approach that led to the successful identification of nonmutagenic examples, as well as further optimization to compounds with reduced cardiovascular liabilities is described. Select pharmacokinetic and in vivo efficacy data are presented.
Assuntos
Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Piridazinas/síntese química , Piridazinas/farmacologia , Baço/enzimologia , Amidas/síntese química , Amidas/farmacologia , Animais , Biologia Computacional , Simulação por Computador , Desenho de Fármacos , Canais de Potássio Éter-A-Go-Go/efeitos dos fármacos , Humanos , Técnicas In Vitro , Camundongos , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Conformação Molecular , Mutagênese/efeitos dos fármacos , Testes de Mutagenicidade , Inibidores de Proteínas Quinases/farmacocinética , Piridazinas/farmacocinética , Ratos , Baço/efeitos dos fármacos , Relação Estrutura-Atividade , Difração de Raios XRESUMO
Organic impurities in compound libraries are known to often cause false-positive signals in screening campaigns for new leads, but organic impurities do not fully account for all false-positive results. We discovered inorganic impurities in our screening library that can also cause positive signals for a variety of targets and/or readout systems, including biochemical and biosensor assays. We investigated in depth the example of zinc for a specific project and in retrospect in various HTS screens at Roche and propose a straightforward counter screen using the chelator TPEN to rule out inhibition caused by zinc.
RESUMO
The Janus kinases (JAKs) are involved in multiple signaling networks relevant to inflammatory diseases, and inhibition of one or more members of this class may modulate disease activity or progression. We optimized a new inhibitor scaffold, 3-amido-5-cyclopropylpyrrolopyrazines, to a potent example with reasonable kinome selectivity, including selectivity for JAK3 versus JAK1, and good biopharmaceutical properties. Evaluation of this analogue in cellular and in vivo models confirmed functional selectivity for modulation of a JAK3/JAK1-dependent IL-2 stimulated pathway over a JAK1/JAK2/Tyk2-dependent IL-6 stimulated pathway.
Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Ciclopropanos/síntese química , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 3/antagonistas & inibidores , Pirazinas/síntese química , Pirróis/síntese química , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/farmacocinética , Anti-Inflamatórios não Esteroides/farmacologia , Células CACO-2 , Cristalografia por Raios X , Ciclopropanos/farmacocinética , Ciclopropanos/farmacologia , Técnicas de Silenciamento de Genes , Ensaios de Triagem em Larga Escala , Humanos , Interleucina-2/fisiologia , Janus Quinase 1/genética , Janus Quinase 1/metabolismo , Janus Quinase 3/genética , Janus Quinase 3/metabolismo , Camundongos , Modelos Moleculares , Pirazinas/farmacocinética , Pirazinas/farmacologia , Pirróis/farmacocinética , Pirróis/farmacologia , RNA Interferente Pequeno/genética , Ratos , Receptores de Interleucina-6/fisiologia , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismoRESUMO
We describe the discovery of several pyrrolopyrazines as potent and selective Syk inhibitors and the efforts that eventually led to the desired improvements in physicochemical properties and human whole blood potencies. Ultimately, our mouse model revealed unexpected toxicity that precluded us from further advancing this series.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirazinas/síntese química , Pirróis/síntese química , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/enzimologia , Proteínas Sanguíneas/metabolismo , Cristalografia por Raios X , Humanos , Camundongos , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Estrutura Molecular , Ligação Proteica , Pirazinas/farmacologia , Pirazinas/toxicidade , Pirróis/farmacologia , Pirróis/toxicidade , Relação Estrutura-Atividade , Quinase SykRESUMO
Jun N-terminal kinase (JNK) is a stress activated serine/threonine protein kinase that phosphorylates numerous cellular protein substrates including the transcription factors c-Jun and ATF2. In this study, we defined the kinetic mechanism for the active form of JNK2alpha2. Double reciprocal plots of initial rates versus concentrations of substrate revealed the sequential nature of the JNK2alpha2 catalyzed ATF2 phosphorylation. Dead-end JNK inhibitors were then used to differentiate ordered and random kinetic mechanisms for the reaction. A peptide inhibitor containing the homology JNK docking sequence for substrate recognition, derived from amino acid residues 153-163 of JNK-interacting protein 1 (JIP-1), inhibited JNK activity via competition with ATF2. This peptide functioned as a noncompetitive inhibitor against ATP. In contrast, the anthrapyrazolone compound, SP600125, exhibited competitive inhibition for ATP and noncompetitive inhibition against ATF2. Furthermore, binding of one substrate had no significant effect on the affinity for the other substrate. The data in this study are consistent with a kinetic mechanism for activated JNK2alpha2 in which (1) substrate binding is primarily due to the distal contacts in the JNK2alpha2 docking groove that allow the delivery of the substrate phosphorylation sequence into the catalytic center, (2) there is minimal allosteric communication between the protein-substrate docking site and the ATP binding site in the catalytic center for activated JNK2alpha2, and (3) the reaction proceeds via a random sequential mechanism.
Assuntos
Antracenos/farmacologia , Inibidores Enzimáticos/farmacologia , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/farmacologia , Ligação Competitiva , Humanos , Cinética , Proteína Quinase 9 Ativada por Mitógeno/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , FosforilaçãoRESUMO
IL-1R-associated kinase (IRAK)4 plays a central role in innate and adaptive immunity, and is a crucial component in IL-1/TLR signaling. We have determined the crystal structures of the apo and ligand-bound forms of human IRAK4 kinase domain. These structures reveal several features that provide opportunities for the design of selective IRAK4 inhibitors. The N-terminal lobe of the IRAK4 kinase domain is structurally distinctive due to a loop insertion after an extended N-terminal helix. The gatekeeper residue is a tyrosine, a unique feature of the IRAK family. The IRAK4 structures also provide insights into the regulation of its activity. In the apo structure, two conformations coexist, differing in the relative orientation of the two kinase lobes and the position of helix C. In the presence of an ATP analog only one conformation is observed, indicating that this is the active conformation.