RESUMO
We identified novel potent inhibitors of p38 mitogen-activated protein (MAP) kinase using a structure-based design strategy, beginning with lead compound, 3-(butan-2-yl)-6-(2,4-difluoroanilino)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (1). To enhance the inhibitory activity of 1 against production of tumor necrosis factor-α (TNF-α) in human whole blood (hWB) cell assays, we designed and synthesized hybrid compounds in which the imidazo[4,5-b]pyridin-2-one core was successfully linked with the p-methylbenzamide fragment. Among the compounds evaluated, 3-(3-tert-butyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-6-yl)-4-methyl-N-(1-methyl-1H-pyrazol-3-yl)benzamide (25) exhibited potent p38 inhibition, superior suppression of TNF-α production in hWB cells, and also significant inâ vivo efficacy in a rat model of collagen-induced arthritis (CIA). In this paper, we report the discovery of potent, selective, and orally bioavailable imidazo[4,5-b]pyridin-2-one-based p38 MAP kinase inhibitors.
Assuntos
Artrite Experimental/tratamento farmacológico , Desenho de Fármacos , Imidazóis/farmacologia , Piridinas/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Artrite Experimental/induzido quimicamente , Linhagem Celular , Colágeno , Cristalografia por Raios X , Modelos Animais de Doenças , Humanos , Imidazóis/síntese química , Imidazóis/química , Modelos Moleculares , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Ratos , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
We identified a lead series of p38 mitogen-activated protein kinase inhibitors using a structure-based design strategy from high-throughput screening of hit compound 1. X-ray crystallography of 1 with the kinase showed an infrequent flip of the peptide bond between Met109 and Gly110, which was considered to lead to high kinase selectivity. Our structure-based design strategy was to conduct scaffold transformation of 1 with maintenance of hydrogen bond interactions with the flipped hinge backbone of the enzyme. In accordance with this strategy, we focused on scaffold transformation to identify imidazo[4,5-b]pyridin-2-one derivatives as potent inhibitors of the p38 MAP kinase. Of the compounds evaluated, 21 was found to be a potent inhibitor of the p38 MAP kinase, lipopolysaccharide-induced tumor necrosis factor-α (TNF-α) production in human monocytic leukemia cells, and TNF-α-induced production of interleukin-8 in human whole blood cells. Herein we describe the discovery of potent and orally bioavailable imidazo[4,5-b]pyridin-2-one-based p38 MAP kinase inhibitors that suppressed cytokine production in a human whole blood cell-based assay.
Assuntos
Antineoplásicos/química , Imidazóis/química , Inibidores de Proteínas Quinases/química , Piridinas/química , Piridonas/química , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacocinética , Células Sanguíneas , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligação de Hidrogênio , Imidazóis/síntese química , Imidazóis/farmacocinética , Interleucina-8/metabolismo , Lipopolissacarídeos/química , Modelos Moleculares , Estrutura Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Piridinas/síntese química , Piridinas/farmacocinética , Piridonas/farmacocinética , Ratos , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
We identified novel potent inhibitors of p38 MAP kinase using structure-based design strategy. X-ray crystallography showed that when p38 MAP kinase is complexed with TAK-715 (1) in a co-crystal structure, Phe169 adopts two conformations, where one interacts with 1 and the other shows no interaction with 1. Our structure-based design strategy shows that these two conformations converge into one via enhanced protein-ligand hydrophobic interactions. According to the strategy, we focused on scaffold transformation to identify imidazo[1,2-b]pyridazine derivatives as potent inhibitors of p38 MAP kinase. Among the herein described and evaluated compounds, N-oxide 16 exhibited potent inhibition of p38 MAP kinase and LPS-induced TNF-α production in human monocytic THP-1 cells, and significant in vivo efficacy in rat collagen-induced arthritis models. In this article, we report the discovery of potent, selective and orally bioavailable imidazo[1,2-b]pyridazine-based p38 MAP kinase inhibitors with pyridine N-oxide group.
Assuntos
Desenho de Fármacos , Inibidores de Proteínas Quinases/síntese química , Piridazinas/química , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Artrite/tratamento farmacológico , Artrite/etiologia , Linhagem Celular , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Simulação de Dinâmica Molecular , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Estrutura Terciária de Proteína , Piridazinas/farmacologia , Piridazinas/uso terapêutico , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
A novel approach was conducted for fragment-based lead discovery and applied to renin inhibitors. The biochemical screening of a fragment library against renin provided the hit fragment which showed a characteristic interaction pattern with the target protein. The hit fragment bound only to the S1, S3, and S3SP (S3 subpocket) sites without any interactions with the catalytic aspartate residues (Asp32 and Asp215 (pepsin numbering)). Prior to making chemical modifications to the hit fragment, we first identified its essential binding sites by utilizing the hit fragment's substructures. Second, we created a new and smaller scaffold, which better occupied the identified essential S3 and S3SP sites, by utilizing library synthesis with high-throughput chemistry. We then revisited the S1 site and efficiently explored a good building block attaching to the scaffold with library synthesis. In the library syntheses, the binding modes of each pivotal compound were determined and confirmed by X-ray crystallography and the library was strategically designed by structure-based computational approach not only to obtain a more active compound but also to obtain informative Structure Activity Relationship (SAR). As a result, we obtained a lead compound offering synthetic accessibility as well as the improved in vitro ADMET profiles. The fragments and compounds possessing a characteristic interaction pattern provided new structural insights into renin's active site and the potential to create a new generation of renin inhibitors. In addition, we demonstrated our FBDD strategy integrating highly sensitive biochemical assay, X-ray crystallography, and high-throughput synthesis and in silico library design aimed at fragment morphing at the initial stage was effective to elucidate a pocket profile and a promising lead compound.
Assuntos
Descoberta de Drogas , Inibidores de Proteases/farmacologia , Renina/antagonistas & inibidores , Animais , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Renina/metabolismo , Relação Estrutura-AtividadeRESUMO
A prediction method for ligand binding affinities to proteins is proposed. We first predict the structures of protein-ligand complex by the replica-exchange umbrella sampling or its extension. We then calculate ligand binding affinities based on these predicted ligand-protein bound structures by the double-decoupling method. As a test of the effectiveness of the proposed method, we applied it to the system of the oncoprotein MDM2 and a ligand. The value of the predicted binding affinity turned out to be in good agreement with that from experiments.
RESUMO
We have developed a two-dimensional replica-exchange method for the prediction of protein-ligand binding structures. The first dimension is the umbrella sampling along the reaction coordinate, which is the distance between a protein binding pocket and a ligand. The second dimension is the solute tempering, in which the interaction between a ligand and a protein and water is weakened. The second dimension is introduced to make a ligand follow the umbrella potential more easily and enhance the binding events, which should improve the sampling efficiency. As test cases, we applied our method to two protein-ligand complex systems (MDM2 and HSP 90-alpha). Starting from the configuration in which the protein and the ligand are far away from each other in each system, our method predicted the ligand binding structures in excellent agreement with the experimental data from Protein Data Bank much faster with the improved sampling efficiency than the replica-exchange umbrella sampling method that we have previously developed.
Assuntos
Benzodiazepinas/química , Proteínas de Choque Térmico HSP90/química , Simulação de Dinâmica Molecular , Proteínas Proto-Oncogênicas c-mdm2/química , Pirimidinas/química , Sítios de Ligação , Ligantes , Modelos Moleculares , Estrutura MolecularRESUMO
Centromere-associated protein-E (CENP-E), a mitotic kinesin that plays an important role in mitotic progression, is an attractive target for cancer therapeutic drugs. For the purpose of developing novel CENP-E inhibitors as cancer therapeutics, we investigated a fused bicyclic compound identified by high throughput screening, 4-oxo-4,5-dihydrothieno[3,4-c]pyridine-6-carboxamide 1a. Based on this scaffold, we designed inhibitors for efficient binding at the L5 site in CENP-E utilizing homology modeling as well as electrostatic potential map (EPM) analysis to enhance CENP-E inhibitory activity. This resulted in a new lead, 5-bromoimidazo[1,2-a]pyridine 7, which showed potent CENP-E enzyme inhibition (IC50: 50nM) and cellular activity with accumulation of phosphorylated histone H3 in HeLa cells. Our homology model and EPM analysis proved to be useful tools for the rational design of CENP-E inhibitors.
Assuntos
Amidas/síntese química , Compostos Bicíclicos com Pontes/química , Proteínas Cromossômicas não Histona/antagonistas & inibidores , Imidazóis/síntese química , Piridinas/síntese química , Amidas/química , Amidas/metabolismo , Sítios de Ligação , Proteínas Cromossômicas não Histona/metabolismo , Células HeLa , Histonas/metabolismo , Humanos , Imidazóis/química , Imidazóis/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Piridinas/química , Piridinas/metabolismo , Eletricidade Estática , Relação Estrutura-AtividadeRESUMO
A novel 7,6 fused bicyclic scaffold, pyrimido[4,5-b]azepine was designed to fit into the ATP binding site of the HER2/EGFR proteins. The synthesis of this scaffold was accomplished by an intramolecular Claisen-type condensation. As the results of optimization lead us to 4-anilino and 6-functional groups, we discovered 6-substituted amide derivative 19b, which has a 1-benzothiophen-4-yloxy group attached to the 4-anilino group. An X-ray co-crystal structure of 19b with EGFR demonstrated that the N-1 and N-3 nitrogens of the pyrimido[4,5-b]azepine scaffold make hydrogen-bonding interactions with the main chain NH of Met793 and the side chain of Thr854 via a water-mediated hydrogen bond network, respectively. In addition, the NH proton at the 9-position makes an additional hydrogen bond with the carbonyl group of Met793, as we expected. Compound 19b revealed potent HER2/EGFR kinase (IC50: 24/36 nM) and BT474 cell growth (GI50: 18 nM) inhibitory activities based on its pseudo-irreversible (PI) profile.
Assuntos
Azepinas/química , Azepinas/farmacologia , Receptores ErbB/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Azepinas/síntese química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Receptores ErbB/química , Receptores ErbB/metabolismo , Feminino , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Receptor ErbB-2/química , Receptor ErbB-2/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
During the course of our studies on a novel HER2/EGFR dual inhibitor (TAK-285), we found an alternative potent pyrrolo[3,2-d]pyrimidine compound (1a). To enhance the pharmacokinetic (PK) profile of this compound, we conducted chemical modifications into its N-5 side chain and conversion of the chemically modified compounds into their salts. Among them, 2cb, the tosylate salt of compound 2c, showed potent HER2/EGFR kinase inhibitory activity (IC(50): 11/11 nM) and cellular growth inhibitory activity (BT-474 cell GI(50): 56 nM) with a good drug metabolism and PK (DMPK) profile. Furthermore, 2cb exhibited significant in vivo antitumor efficacy in both mouse and rat xenograft models with transplanted 4-1ST gastric cancer cell lines (mouse, T/C=0%, 2cb po bid at 100 mg/kg; rat, T/C: -1%, 2cb po bid at 25 mg/kg).
Assuntos
Antineoplásicos/síntese química , Desenho de Fármacos , Receptores ErbB/antagonistas & inibidores , Inibidores de Proteínas Quinases/síntese química , Pirimidinas/química , Pirimidinas/síntese química , Pirróis/química , Receptor ErbB-2/antagonistas & inibidores , Sulfonas/síntese química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Meia-Vida , Humanos , Camundongos , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Pirróis/farmacocinética , Pirróis/uso terapêutico , Ratos , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Sulfonas/química , Sulfonas/farmacocinética , Transplante HeterólogoRESUMO
As part of a program to identify potent GPR40 agonists with drug-like properties suitable for clinical development, the incorporation of polar substituents was explored with the intention of decreasing the lipophilicity of our recently disclosed phenylpropanoic acid derivative 1. This incorporation would allow us to mitigate the cytotoxicity issues observed with compound 1 and enable us to move away from the multifunctional free fatty acid-like structure. Substitutions on the 2',6'-dimethylbiphenyl ring were initially undertaken, which revealed the feasibility of introducing polar functionalities at the biphenyl 4'-position. Further optimization of this position and the linker led to the discovery of several 4'-alkoxybiphenyl derivatives, which showed potent GPR40 agonist activities with the best balance in terms of improved cytotoxicity profiles and favorable pharmacokinetic properties. Among them, 3-{2-fluoro-4-[({4'-[(4-hydroxy-1,1-dioxidotetrahydro-2H-thiopyran-4-yl)methoxy]-2',6'-dimethylbiphenyl-3-yl}methyl)amino]phenyl}propanoic acid (35) exhibited a robust plasma glucose-lowering effect and insulinotropic action during an oral glucose tolerance test in rats with impaired glucose tolerance.
Assuntos
Óxidos S-Cíclicos/síntese química , Hipoglicemiantes/síntese química , Fenilpropionatos/síntese química , Receptores Acoplados a Proteínas G/agonistas , Animais , Células CHO , Cálcio/metabolismo , Caspases/metabolismo , Sobrevivência Celular , Cricetinae , Óxidos S-Cíclicos/farmacocinética , Óxidos S-Cíclicos/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Intolerância à Glucose/tratamento farmacológico , Células Hep G2 , Humanos , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Concentração Inibidora 50 , Masculino , Fenilpropionatos/farmacocinética , Fenilpropionatos/uso terapêutico , Ratos , Receptores Acoplados a Proteínas G/metabolismo , Relação Estrutura-AtividadeRESUMO
To develop novel human epidermal growth factor receptor 2 (HER2)/epidermal growth factor receptor (EGFR) kinase inhibitors, we explored pyrrolo[3,2-d]pyrimidine derivatives bearing bicyclic fused rings designed to fit the back pocket of the HER2/EGFR proteins. Among them, the 1,2-benzisothiazole (42m) ring was selected as a suitable back pocket binder because of its potent HER2/EGFR binding and cell growth inhibitory (GI) activities and pseudoirreversibility (PI) profile as well as good bioavailability (BA). Ultimately, we arrived at our preclinical candidate 51m by optimization of the N-5 side chain to improve CYP inhibition and metabolic stability profiles without a loss of potency (HER2/EGFR inhibitory activity, IC(50), 0.98/2.5 nM; and GI activity BT-474 cells, GI(50), 2.0 nM). Reflecting the strong in vitro activities, 51m exhibited potent tumor regressive efficacy against both HER2- and EGFR-overexpressing tumor (4-1ST and CAL27) xenograft models in mice at oral doses of 50 mg/kg and 100 mg/kg.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Receptores ErbB/antagonistas & inibidores , Hidroxibutiratos/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/síntese química , Pirróis/síntese química , Receptor ErbB-2/antagonistas & inibidores , Animais , Disponibilidade Biológica , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Feminino , Humanos , Hidroxibutiratos/síntese química , Camundongos , Pirimidinas/farmacologia , Pirróis/farmacologia , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A novel naphthylmethylimidazole derivative 1 and its related compounds were identified as 17,20-lyase inhibitors. Based on the structure-activity relationship around the naphthalene scaffold and the results of a docking study of 1a in the homology model of 17,20-lyase, the 6,7-dihydro-5H-pyrrolo[1,2-c]imidazole derivative (+)-3c was synthesized and identified as a potent and highly selective 17,20-lyase inhibitor. Biological evaluation of (+)-3c at a dose of 1mg/kg in a male monkey model revealed marked reductions in both serum testosterone and dehydroepiandrosterone concentrations. Therefore, (+)-3c (termed orteronel [TAK-700]) was selected as a candidate for clinical evaluation and is currently in phase III clinical trials for the treatment of castration-resistant prostate cancer.
Assuntos
Antineoplásicos/química , Inibidores Enzimáticos/química , Imidazóis/farmacologia , Naftalenos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Cristalografia por Raios X , Desidroepiandrosterona/sangue , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Haplorrinos , Humanos , Imidazóis/síntese química , Imidazóis/química , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Masculino , Modelos Moleculares , Simulação de Dinâmica Molecular , Naftalenos/síntese química , Naftalenos/química , Neoplasias da Próstata/sangue , Neoplasias da Próstata/enzimologia , Estereoisomerismo , Relação Estrutura-Atividade , Testosterona/sangueRESUMO
Dual inhibitors of human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) have been investigated for breast, lung, gastric, prostate, and other cancers; one, lapatinib, is currently approved for breast cancer. To develop novel HER2/EGFR dual kinase inhibitors, we designed and synthesized pyrrolo[3,2-d]pyrimidine derivatives capable of fitting into the receptors' ATP binding site. Among the prepared compounds, 34e showed potent HER2 and EGFR (HER1) inhibitory activities as well as tumor growth inhibitory activity. The X-ray cocrystal structures of 34e with both HER2 and EGFR demonstrated that 34e interacts with the expected residues in their respective ATP pockets. Furthermore, reflecting its good oral bioavailability, 34e exhibited potent in vivo efficacy in HER2-overexpressing tumor xenograft models. On the basis of these findings, we report 34e (TAK-285) as a promising candidate for clinical development as a novel HER2/EGFR dual kinase inhibitor.
Assuntos
Antineoplásicos/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Receptores ErbB/antagonistas & inibidores , Hidroxibutiratos/síntese química , Pirimidinas/síntese química , Pirróis/síntese química , Receptor ErbB-2/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Sítios de Ligação , Disponibilidade Biológica , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Hidroxibutiratos/farmacocinética , Hidroxibutiratos/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Transplante de Neoplasias , Conformação Proteica , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Pirróis/farmacocinética , Pirróis/farmacologia , Ratos , Relação Estrutura-Atividade , Transplante HeterólogoRESUMO
Aberrant signaling of ErbB family members human epidermal growth factor 2 (HER2) and epidermal growth factor receptor (EGFR) is implicated in many human cancers, and HER2 expression is predictive of human disease recurrence and prognosis. Small molecule kinase inhibitors of EGFR and of both HER2 and EGFR have received approval for the treatment of cancer. We present the first high resolution crystal structure of the kinase domain of HER2 in complex with a selective inhibitor to understand protein activation, inhibition, and function at the molecular level. HER2 kinase domain crystallizes as a dimer and suggests evidence for an allosteric mechanism of activation comparable with previously reported activation mechanisms for EGFR and HER4. A unique Gly-rich region in HER2 following the α-helix C is responsible for increased conformational flexibility within the active site and could explain the low intrinsic catalytic activity previously reported for HER2. In addition, we solved the crystal structure of the kinase domain of EGFR in complex with a HER2/EGFR dual inhibitor (TAK-285). Comparison with previously reported inactive and active EGFR kinase domain structures gave insight into the mechanism of HER2 and EGFR inhibition and may help guide the design and development of new cancer drugs with improved potency and selectivity.
Assuntos
Receptor ErbB-2/química , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/genética , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Cristalografia por Raios X , Desenho de Fármacos , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Receptores ErbB/química , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/genética , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Estrutura Terciária de Proteína , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptor ErbB-4 , Relação Estrutura-AtividadeRESUMO
The p38 mitogen-activated protein (MAP) kinase has been implicated in the proinflammatory cytokine signal pathway, and its inhibitors are potentially useful for the treatment of chronic inflammatory diseases such as rheumatoid arthritis (RA) and inflammatory bowel disease. To develop a new drug for RA, we synthesized a novel series of 4-phenyl-5-pyridyl-1,3-thiazoles and evaluated their inhibition of p38 MAP kinase, lipopolysaccharide (LPS)-stimulated release of tumor necrosis factor-alpha (TNF-alpha) from human monocytic THP-1 cells in vitro, and LPS-induced TNF-alpha production in vivo in mice. During the course of the study, we found that these compounds risk the inhibition of cytochrome P450 (CYP) isoforms by coordination of the 4-pyridyl nitrogen with heme iron. We therefore investigated the effects of substitution at the 2-position of the pyridyl ring on the inhibitory activity of p38 MAP kinase and CYPs in more detail. As a result, N-[4-[2-ethyl-4-(3-methylphenyl)-1,3-thiazol-5-yl]-2-pyridyl]benzamide (8h, TAK-715) exhibited potent inhibitory activity in these assays (inhibition of p38alpha, IC50 = 7.1 nM; LPS-stimulated release of TNF-alpha from THP-1, IC50 = 48 nM; LPS-induced TNF-alpha production in mice, 87.6% inhibition at 10 mg/kg, po) and no inhibitory activity for major CYPs, including CYP3A4. This compound also showed good bioavailability in mice and rats and significant efficacy in a rat adjuvant-induced arthritis model. Compound 8h was selected as a clinical candidate and is now under clinical investigation for the treatment of RA.
Assuntos
Antirreumáticos/síntese química , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Benzamidas/síntese química , Tiazóis/síntese química , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Administração Oral , Animais , Antirreumáticos/química , Antirreumáticos/farmacologia , Benzamidas/química , Benzamidas/farmacologia , Disponibilidade Biológica , Linhagem Celular , Linhagem Celular Tumoral , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450 , Humanos , Técnicas In Vitro , Isoenzimas/antagonistas & inibidores , Masculino , Camundongos , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , Modelos Moleculares , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-Atividade , Tiazóis/química , Tiazóis/farmacologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
A series of 1- and 4-(2-naphthylmethyl)-1H-imidazoles (3 and 4) has been synthesized and evaluated as C(17,20)-lyase inhibitors. Several 6-methoxynaphthyl derivatives showed potent C(17,20)-lyase inhibition, suppression of testosterone biosynthesis in rats and reduction in the weight of prostate and seminal vesicles in rats, whereas most of these compounds increased the liver weight after consecutive administrations. The effect on the liver weight was removed by incorporation of a hydroxy group and an isopropyl group at the methylene bridge, as seen in (S)-28d and (S)-42. Selectivity for C(17,20)-lyase over 11beta-hydroxylase is also discussed, and (S)-42 was found to be a more than 260-fold selective inhibitor. Furthermore, (S)-42 showed a potent suppression of testosterone biosynthesis after a single oral administration in monkeys. These data suggest that (S)-42 may be a promising agent for the treatment of androgen-dependent prostate cancer.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Imidazóis/síntese química , Imidazóis/farmacologia , Liases/antagonistas & inibidores , Animais , Inibidores Enzimáticos/química , Humanos , Imidazóis/química , Fígado/efeitos dos fármacos , Masculino , Modelos Químicos , Próstata/efeitos dos fármacos , Neoplasias da Próstata/tratamento farmacológico , Ligação Proteica , Ratos , Glândulas Seminais/efeitos dos fármacos , Relação Estrutura-Atividade , Testosterona/biossínteseRESUMO
To compare the features of the active sites of CYP2C8, CYP2C9, and CYP2C19, homology modeling was performed based on the crystallographic coordinates of mammalian CYP2C5. It was found that CYP2C8 has a much larger pocket than the other forms due to the existence of an additional pocket. The approach to the additional pocket is comprised of Ile102, Ser114, Leu208, Val366, and Ile476, and the side chains of Ser114, Val366, and Ile476, which are smaller than the corresponding residues in the other CYPs, enable access to the pocket. The general features of the active site in the CYP2C8 model are similar to those of the previously constructed CYP3A4 model, which may account for the 2 CYPs sharing some of their substrates. The CYP2C8 model was validated by examining the bound orientation of paclitaxel and showing that it is consistent with the formation of the 6-beta hydroxylated derivative during metabolism. Docked paclitaxel was found to form a hydrogen bond with the side chain of Asn 99, which is a characteristic residue of CYP2C8 and is located in the additional pocket. Descriptors for CYP2C8 and CYP2C9 substrates were also examined with the molecular operating environment (MOE). The descriptor by which CYP2C8 and CYP2C9 substrates were classified most distinctly was found to be molar refractivity, which might be related to the longer shape and more polar nature of the active site of CYP2C8 in the CYP2C subfamily.