RESUMEN
S1P Lyase (SPL) has been described as a drug target in the treatment of autoimmune diseases. It plays an important role in maintaining intracellular levels of S1P thereby affecting T cell egress from lymphoid tissues. Several groups have already published approaches to inhibit S1P Lyase with small molecules, which in turn increase endogenous S1P concentrations resulting in immunosuppression. The use of structural biology has previously aided SPL inhibitor design. Novel construct design is at times necessary to provide a reagent for protein crystallography. Here we present a chimeric bacterial protein scaffold used for protein X-ray structures in the presence of early small molecule inhibitors. Mutations were introduced to the bacterial SPL from Symbiobacterium thermophilum which mimic the human enzyme. As a result, two mutant StSPL crystal structures resolved to 2.8Å and 2.2Å resolutions were solved and provide initial structural hypotheses for an isoxazole chemical series, whose optimization is discussed in the accompanying paper.
Asunto(s)
Aldehído-Liasas/metabolismo , Diseño de Fármacos , Escherichia coli/enzimología , Aldehído-Liasas/química , Cristalografía por Rayos XRESUMEN
Inhibition of sphingosine-1-phosphate lyase has recently been proposed as a potential treatment option for inflammatory disorders such as multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease. In this report we describe our hit-to-lead evaluation of the isoxazolecarboxamide 6, a high-throughput screening hit (in vitro IC50=1.0 µM, cell IC50=1.8 µM), as a novel S1P lyase inhibitor. We were able to establish basic structure-activity relationships around 6 and succeeded in obtaining X-ray structural information which enabled structure-based design. With the discovery of 28, enzyme activity was quickly improved to IC50=120 nM and cell potency to IC50=230 nM. The main liability in the established isoxazolecarboxamide hit series was determined to be metabolic stability. In particular we identified that future lead-optimization efforts to overcome this problem should focus on blocking the N-dealkylation on the secondary amine.
Asunto(s)
Aldehído-Liasas/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/química , Humanos , Relación Estructura-ActividadRESUMEN
The synthesis of a novel series of 1,4-dihydroindeno[1,2-c]pyrazoles with acetylene-type side chains is described. Optimization of those compounds as KDR kinase inhibitors identified 8, which displayed an oral activity in an estradiol-induced murine uterine edema model (ED50 = 3 mg/kg) superior to Sutent (ED50 = 9 mg/kg) and showed potent antitumor efficacy in an MX-1 human breast carcinoma xenograft tumor growth model (tumor growth inhibition = 90% at 25 mg/kg.day po). The compound was docked into a homology model of the homo-tetrameric pore domain of the hERG potassium channel to identify strategies to improve its cardiac safety profile. Systematic interruption of key binding interactions between 8 and Phe656, Tyr652, and Ser624 yielded 90, which only showed an IC50 of 11.6 microM in the hERG patch clamp assay. The selectivity profile for 8 and 90 revealed that both compounds are multitargeted receptor tyrosine kinase inhibitors with low nanomolar potencies against the members of the VEGFR and PDGFR kinase subfamilies.
Asunto(s)
Alquinos/síntesis química , Antineoplásicos/síntesis química , Canales de Potasio Éter-A-Go-Go/efectos de los fármacos , Indenos/síntesis química , Pirazoles/síntesis química , Receptores del Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Tiofenos/síntesis química , Alquinos/efectos adversos , Alquinos/farmacología , Animales , Antineoplásicos/efectos adversos , Antineoplásicos/farmacología , Unión Competitiva , Línea Celular , Canal de Potasio ERG1 , Edema/inducido químicamente , Edema/tratamiento farmacológico , Estradiol , Canales de Potasio Éter-A-Go-Go/fisiología , Femenino , Humanos , Indenos/efectos adversos , Indenos/farmacología , Ratones , Ratones Endogámicos BALB C , Modelos Moleculares , Técnicas de Placa-Clamp , Unión Proteica , Pirazoles/efectos adversos , Pirazoles/metabolismo , Pirazoles/farmacología , Ensayo de Unión Radioligante , Estereoisomerismo , Relación Estructura-Actividad , Tiofenos/metabolismo , Tiofenos/farmacología , Enfermedades Uterinas/inducido químicamente , Enfermedades Uterinas/tratamiento farmacológico , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
We report the synthesis and biological evaluation of 5-substituted 1,4-dihydroindeno[1,2-c]pyrazoles as multitargeted kinase inhibitors. Initial efforts focused on the development of selective KDR inhibitors, while later strategies involved the improvement of potency toward multiple kinase targets. Thus, several compounds were identified as potent KDR, Flt1, Flt3, and c-Kit inhibitors.
Asunto(s)
Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/química , Pirazoles/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Animales , Humanos , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Pirazoles/síntesis químicaRESUMEN
A novel class of adamantane ethers 11beta-hydroxysteroid hydrogenase type I inhibitors has been discovered. These compounds have excellent HSD-1 potency and selectivity against HSD-2. The structure-activity relationships, selectivity, metabolism, PK, ex vivo pharmacodynamic data, and an X-ray crystal structure of one of these inhibitors bound to h-HSD-1 are discussed.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/antagonistas & inhibidores , Adamantano/análogos & derivados , Adamantano/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , Adamantano/síntesis química , Alquilación , Animales , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Éteres/síntesis química , Éteres/farmacología , Semivida , Humanos , Indicadores y Reactivos , Ratones , Ratones Noqueados , Microsomas Hepáticos/enzimología , Microsomas Hepáticos/metabolismo , Modelos MolecularesRESUMEN
A series of 1,4-dihydroindeno[1,2-c]pyrazoles was prepared and evaluated for their enzymatic inhibition of KDR kinase. Computer modeling studies revealed the importance of attaching a basic side chain in predicting the binding mode of those compounds. Further investigation of structure-activity relationships led to 19, a lead compound with an acceptable selectivity profile, activity in whole cells, and good oral efficacy in an estradiol-induced murine uterine edema model of VEGF activity.
Asunto(s)
Indenos/farmacología , Pirazoles/farmacología , Administración Oral , Animales , Química Farmacéutica , Diseño de Fármacos , Edema/patología , Estradiol/farmacología , Femenino , Indenos/química , Concentración 50 Inhibidora , Ratones , Modelos Químicos , Modelos Moleculares , Pirazoles/química , Relación Estructura-Actividad , Útero/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/químicaRESUMEN
A series of 1,4-dihydroindeno[1,2-c]pyrazoles with a 3-thiophene substituent carrying a urea-type side chain were identified as potent multitargeted (VEGFR and PDGFR families) receptor tyrosine kinase inhibitors. A KDR homology model suggested that the urea moiety is able to interact with a recognition motif in the hydrophobic specificity pocket of the enzyme.
Asunto(s)
Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirazoles/síntesis química , Pirazoles/farmacología , Secuencias de Aminoácidos , Química Farmacéutica/métodos , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Humanos , Enlace de Hidrógeno , Concentración 50 Inhibidora , Microsomas Hepáticos/metabolismo , Modelos Químicos , Modelos Moleculares , Urea/químicaRESUMEN
The antiapoptotic proteins Bcl-x(L) and Bcl-2 play key roles in the maintenance of normal cellular homeostasis. However, their overexpression can lead to oncogenic transformation and is responsible for drug resistance in certain types of cancer. This makes Bcl-x(L) and Bcl-2 attractive targets for the development of potential anticancer agents. Here we describe the structure-based discovery of a potent Bcl-x(L) inhibitor directed at a hydrophobic groove on the surface of the protein. This groove represents the binding site for BH3 peptides from proapoptotic Bcl-2 family members such as Bak and Bad. Application of NMR-based screening yielded an initial biaryl acid with an affinity (K(d)) of approximately 300 microM for the protein. Following the classical "SAR by NMR" approach, a second-site ligand was identified that bound proximal to the first-site ligand in the hydrophobic groove. From NMR-based structural studies and parallel synthesis, a potent ligand was obtained, which binds to Bcl-x(L) with an inhibition constant (K(i)) of 36 +/- 2 nM.
Asunto(s)
Compuestos de Anilina/síntesis química , Modelos Moleculares , Sulfonamidas/síntesis química , Proteína bcl-X/antagonistas & inhibidores , Compuestos de Anilina/química , Sitios de Unión , Interacciones Hidrofóbicas e Hidrofílicas , Ligandos , Espectroscopía de Resonancia Magnética , Unión Proteica , Solubilidad , Relación Estructura-Actividad , Sulfonamidas/química , Proteína bcl-X/químicaRESUMEN
Structure-based design and synthesis of the 3,4'-bispyridinylethylene series led to the discovery of 3-isoquinolinylpyridine 13a as a potent PKB/Akt inhibitor with an IC(50) of 1.3nM against Akt1. Compound 13a shows excellent selectivity against distinct families of kinases such as tyrosine kinases and CAMK, and displays poor to marginal selectivity against closely related kinases in the AGC and CMGC families. Moreover, 13a demonstrates potent cellular activity comparable to staurosporine, with IC(50) values of 0.42 and 0.59microM against MiaPaCa-2 and the Akt1 overexpressing FL5.12-Akt1, respectively. Inhibition of phosphorylation of the Akt downstream target GSK3 was also observed in FL5.12-Akt1 cells with an EC(50) of 1.5microM. The X-ray structures of 12 and 13a in complex with PKA in the ATP-binding site were determined.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Neoplasias/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Piridinas/síntesis química , Piridinas/farmacología , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Línea Celular , Enlace de Hidrógeno , Modelos Moleculares , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/química , Piridinas/uso terapéutico , Relación Estructura-Actividad , Difracción de Rayos XRESUMEN
Proteins in the Bcl-2 family are central regulators of programmed cell death, and members that inhibit apoptosis, such as Bcl-X(L) and Bcl-2, are overexpressed in many cancers and contribute to tumour initiation, progression and resistance to therapy. Bcl-X(L) expression correlates with chemo-resistance of tumour cell lines, and reductions in Bcl-2 increase sensitivity to anticancer drugs and enhance in vivo survival. The development of inhibitors of these proteins as potential anti-cancer therapeutics has been previously explored, but obtaining potent small-molecule inhibitors has proved difficult owing to the necessity of targeting a protein-protein interaction. Here, using nuclear magnetic resonance (NMR)-based screening, parallel synthesis and structure-based design, we have discovered ABT-737, a small-molecule inhibitor of the anti-apoptotic proteins Bcl-2, Bcl-X(L) and Bcl-w, with an affinity two to three orders of magnitude more potent than previously reported compounds. Mechanistic studies reveal that ABT-737 does not directly initiate the apoptotic process, but enhances the effects of death signals, displaying synergistic cytotoxicity with chemotherapeutics and radiation. ABT-737 exhibits single-agent-mechanism-based killing of cells from lymphoma and small-cell lung carcinoma lines, as well as primary patient-derived cells, and in animal models, ABT-737 improves survival, causes regression of established tumours, and produces cures in a high percentage of the mice.
Asunto(s)
Antineoplásicos/uso terapéutico , Compuestos de Bifenilo/farmacología , Compuestos de Bifenilo/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/clasificación , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Compuestos de Bifenilo/síntesis química , Compuestos de Bifenilo/química , Carcinoma de Células Pequeñas/tratamiento farmacológico , Carcinoma de Células Pequeñas/patología , Línea Celular Tumoral , Citocromos c/metabolismo , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Humanos , Linfoma/tratamiento farmacológico , Linfoma/patología , Espectroscopía de Resonancia Magnética , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Modelos Moleculares , Nitrofenoles , Paclitaxel/farmacología , Piperazinas , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Relación Estructura-Actividad , Sulfonamidas , Tasa de SupervivenciaRESUMEN
Further SAR studies on novel histamine H(3) receptor antagonists are presented. Compound 14bb is a potent antagonist of both the rat cortical and human clone receptors, and is demonstrated to act functionally as an antagonist in an in vivo mouse dipsogenia model.
Asunto(s)
Antagonistas de los Receptores Histamínicos/química , Antagonistas de los Receptores Histamínicos/farmacología , Oxadiazoles/química , Oxadiazoles/farmacología , Receptores Histamínicos H3/química , Receptores Histamínicos H3/efectos de los fármacos , Animales , Humanos , Ligandos , Ratones , Modelos Animales , Estructura Molecular , Ratas , Receptores Histamínicos H3/metabolismo , Relación Estructura-ActividadRESUMEN
Biaryl nitrile amines were prepared and found to have high affinity and selectivity for human and rat histamine H(3) receptors.