RESUMEN
The medicinal chemistry and structure-activity relationships (SAR) for a novel series of carbamoyl pyridone bicycle (CAB) compounds as influenza Cap-dependent endonuclease (CEN) inhibitors are disclosed. Substituent effects were evaluated at the C (N)-1, N-3, and C-7 positions of the CAB ring system using a docking study. Submicromolar EC50 values were achieved in the cellular assay with C-7-unsubstituted CAB which possessed a benzhydryl group on either the C-1 or the N-1 position. An N-3 substituent was found to be critical for the plasma protein binding effect in vitro, and the CAB-N analogue 2v exhibited reasonable total clearance (CLtot). More importantly, compound 2v displayed significant efficacy in a mouse model infected with influenza viruses.
Asunto(s)
Antivirales/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Endonucleasas/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Orthomyxoviridae/efectos de los fármacos , Piridonas/farmacología , Antivirales/síntesis química , Antivirales/química , Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Relación Dosis-Respuesta a Droga , Endonucleasas/metabolismo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Orthomyxoviridae/enzimología , Piridonas/síntesis química , Piridonas/química , Relación Estructura-ActividadRESUMEN
Cap-dependent endonuclease (CEN) resides in the PA subunit of the influenza virus and mediates the critical "cap-snatching" step of viral RNA transcription, which is considered to be a promising anti-influenza target. Here, we describe in vitro characterization of a novel CEN inhibitor, baloxavir acid (BXA), the active form of baloxavir marboxil (BXM). BXA inhibits viral RNA transcription via selective inhibition of CEN activity in enzymatic assays, and inhibits viral replication in infected cells without cytotoxicity in cytopathic effect assays. The antiviral activity of BXA is also confirmed in yield reduction assays with seasonal type A and B viruses, including neuraminidase inhibitor-resistant strains. Furthermore, BXA shows broad potency against various subtypes of influenza A viruses (H1N2, H5N1, H5N2, H5N6, H7N9 and H9N2). Additionally, serial passages of the viruses in the presence of BXA result in isolation of PA/I38T variants with reduced BXA susceptibility. Phenotypic and genotypic analyses with reverse genetics demonstrate the mechanism of BXA action via CEN inhibition in infected cells. These results reveal the in vitro characteristics of BXA and support clinical use of BXM to treat influenza.
Asunto(s)
Antivirales/farmacología , Endonucleasas/antagonistas & inhibidores , Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza B/efectos de los fármacos , Oxazinas/farmacología , Piridinas/farmacología , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Tiepinas/farmacología , Triazinas/farmacología , Proteínas Virales/antagonistas & inhibidores , Efecto Citopatogénico Viral , Análisis Mutacional de ADN , Dibenzotiepinas , Farmacorresistencia Viral , Endonucleasas/genética , Virus de la Influenza A/enzimología , Virus de la Influenza A/crecimiento & desarrollo , Virus de la Influenza B/enzimología , Virus de la Influenza B/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Morfolinas , Mutación Missense , Piridonas , ARN Polimerasa Dependiente del ARN/genética , Genética Inversa , Pase Seriado , Transcripción Genética/efectos de los fármacos , Proteínas Virales/genética , Replicación Viral/efectos de los fármacosRESUMEN
NS2B-NS3 protease is an essential enzyme for the replication of dengue virus (DENV), which continues to be a serious threat to worldwide public health. We designed and synthesized a series of cyclic peptides mimicking the substrates of this enzyme, and assayed their activity against the DENV-2 NS2B-NS3 protease. The introduction of aromatic residues at the appropriate positions and conformational restriction generated the most promising cyclic peptide with an IC50 of 0.95µM against NS2B-NS3 protease. Cyclic peptides with proper positioning of additional arginines and aromatic residues exhibited antiviral activity against DENV. Furthermore, replacing the C-terminal amide bond of the polybasic amino acid sequence with an amino methylene moiety stabilized the cyclic peptides against hydrolysis by NS2B-NS3 protease, while maintaining their enzyme inhibitory activity and antiviral activity.
Asunto(s)
Antivirales/química , Antivirales/farmacología , Virus del Dengue/efectos de los fármacos , Dengue/tratamiento farmacológico , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Serina Endopeptidasas/metabolismo , Dengue/virología , Virus del Dengue/enzimología , Humanos , Simulación del Acoplamiento Molecular , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacologíaRESUMEN
We report the discovery of a novel series of influenza Cap-dependent EndoNuclease (CEN) inhibitors based on the 4-pyridone-carboxylic acid (PYXA) scaffold, which were found from our chelate library. Our SAR research revealed the lipophilic domain to be the key to CEN inhibition. In particular, the position between the chelate and the lipophilic domain in the derivatives was essential for enhancing the potency. Our study, based on virtual modeling, led to the identification of 2y as a potent CEN inhibitor with an IC50 of 5.12nM.
Asunto(s)
Antivirales/farmacología , Descubrimiento de Drogas , Endonucleasas/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Orthomyxoviridae/efectos de los fármacos , Piridonas/química , Antivirales/química , Ácidos Carboxílicos/química , Cristalografía por Rayos X , Inhibidores Enzimáticos/química , Concentración 50 Inhibidora , Simulación del Acoplamiento Molecular , Relación Estructura-ActividadRESUMEN
Wnt5a activates the Wnt/ß-catenin-independent pathway and its overexpression is associated with tumor aggressiveness enhancing invasive activity. For this action, Wnt5a-induced receptor endocytosis with clathrin is required. Wnt5a expression was previously believed to be associated with cancer cell motility but not proliferation. Recently, it was reported that Wnt5a is also implicated in cancer cell proliferation, but the mechanism was not clear. In this study, we generated a neutralizing anti-Wnt5a monoclonal antibody (mAb5A16) to investigate the mechanism by which Wnt5a regulates cancer cell proliferation. Wnt5a stimulated both invasion and proliferation of certain types of cancer cells, including HeLaS3 cervical cancer cells and A549 lung cancer cells although Wnt5a promoted invasion but not proliferation in other cancer cells such as KKLS gastric cancer cells. mAb5A16 did not affect the binding of Wnt5a to its receptor, but it suppressed Wnt5a-induced receptor-mediated endocytosis. mAb5A16 inhibited invasion but not proliferation of HeLaS3 and A549 cells. Wnt5a activated Src family kinases (SFKs) and Wnt5a-dependent cancer cell proliferation was dependent on SFKs, yet blockade of receptor-mediated endocytosis did not affect cancer cell proliferation and SFK activity. These results suggest that Wnt5a promotes invasion and proliferation of certain types of cancer cells through receptor-mediated endocytosis-dependent and -independent mechanisms, respectively.
Asunto(s)
Endocitosis , Proteínas Proto-Oncogénicas/metabolismo , Receptores Wnt/metabolismo , Proteínas Wnt/metabolismo , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/farmacología , Anticuerpos Neutralizantes/uso terapéutico , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Endocitosis/efectos de los fármacos , Epítopos/inmunología , Células HeLa , Humanos , Neoplasias Hepáticas/prevención & control , Neoplasias Hepáticas/secundario , Ratones , Ratones Desnudos , Datos de Secuencia Molecular , Biblioteca de Péptidos , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/inmunología , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Receptores Wnt/inmunología , Neoplasias Gástricas/patología , Trasplante Heterólogo , Proteínas Wnt/antagonistas & inhibidores , Proteínas Wnt/inmunología , Vía de Señalización Wnt/efectos de los fármacos , Proteína Wnt-5a , Familia-src Quinasas/metabolismoRESUMEN
Signature HIV-1 integrase mutations associated with clinical raltegravir resistance involve 1 of 3 primary genetic pathways, Y143C/R, Q148H/K/R and N155H, the latter 2 of which confer cross-resistance to elvitegravir. In accord with clinical findings, in vitro drug resistance profiling studies with wild-type and site-directed integrase mutant viruses have shown significant fold increases in raltegravir and elvitegravir resistance for the specified viral mutants relative to wild-type HIV-1. Dolutegravir, in contrast, has demonstrated clinical efficacy in subjects failing raltegravir therapy due to integrase mutations at Y143, Q148 or N155, which is consistent with its distinct in vitro resistance profile as dolutegravir's antiviral activity against these viral mutants is equivalent to its activity against wild-type HIV-1. Kinetic studies of inhibitor dissociation from wild-type and mutant integrase-viral DNA complexes have shown that dolutegravir also has a distinct off-rate profile with dissociative half-lives substantially longer than those of raltegravir and elvitegravir, suggesting that dolutegravir's prolonged binding may be an important contributing factor to its distinct resistance profile. To provide a structural rationale for these observations, we constructed several molecular models of wild-type and clinically relevant mutant HIV-1 integrase enzymes in complex with viral DNA and dolutegravir, raltegravir or elvitegravir. Here, we discuss our structural models and the posited effects that the integrase mutations and the structural and electronic properties of the integrase inhibitors may have on the catalytic pocket and inhibitor binding and, consequently, on antiviral potency in vitro and in the clinic.
Asunto(s)
Inhibidores de Integrasa VIH/metabolismo , Integrasa de VIH/genética , VIH-1/genética , VIH-1/metabolismo , Compuestos Heterocíclicos con 3 Anillos/metabolismo , Provirus/genética , Farmacorresistencia Viral/genética , Integrasa de VIH/metabolismo , Inhibidores de Integrasa VIH/química , Inhibidores de Integrasa VIH/farmacología , Duplicado del Terminal Largo de VIH/genética , VIH-1/efectos de los fármacos , Compuestos Heterocíclicos con 3 Anillos/química , Compuestos Heterocíclicos con 3 Anillos/farmacología , Humanos , Cinética , Modelos Moleculares , Simulación del Acoplamiento Molecular , Estructura Molecular , Conformación de Ácido Nucleico , Oxazinas , Piperazinas , Unión Proteica , Conformación Proteica , PiridonasRESUMEN
For further investigation of BACE1 inhibitors using conformational restriction with sp(3) hybridized carbon, we applied this approach to 6-substituted aminopyrimidone derivatives 3 to improve the inhibitory activity by reducing the entropic energy loss upon binding to BACE1. Among eight stereoisomers synthesized, [trans-(1'R,2'R),6S] isomer 6 exhibited the best BACE1 inhibitory activity, which was statistically superior to that of the corresponding ethylene linker compound (R)-3. Combinational examinations of the binding mode of 6 were performed, which included isothermal titration calorimetry (ITC), X-ray crystallographic structure analysis and theoretical calculations, to clarify the effect of our conformational restriction approach. From the ITC measurement, the binding entropy of 6 was found to be â¼0.5kcal larger than that of (R)-3, which is considered to be affected by conformational restriction with a cyclopropane ring.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Modelos Moleculares , Inhibidores de Proteasas/química , Amidas/síntesis química , Amidas/química , Amidas/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Sitios de Unión , Calorimetría , Cristalografía por Rayos X , Humanos , Conformación Molecular , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Estereoisomerismo , Relación Estructura-Actividad , TermodinámicaRESUMEN
To improve the efficacy of the conformationally restricted BACE1 inhibitors, structural modifications were investigated using two strategies: (a) modification of the terminal aromatic ring and (b) insertion of a spacer between the aromatic rings. In the latter approach, another type of inhibitor 17 bearing an ethylene spacer between two aromatic rings was found to exhibit good BACE1 inhibitory activity, while the corresponding conformationally unrestricted compound 25 showed no activity. This result revealed an interesting effect of a conformational restriction with a cyclopropane ring.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Ciclopropanos/química , Citosina/análogos & derivados , Inhibidores Enzimáticos/farmacología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Cristalografía por Rayos X , Citosina/síntesis química , Citosina/química , Citosina/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Modelos Moleculares , Conformación Molecular , Relación Estructura-ActividadRESUMEN
Improvement of a drug's binding activity using the conformational restriction approach with sp³ hybridized carbon is becoming a key strategy in drug discovery. We applied this approach to BACE1 inhibitors and designed four stereoisomeric cyclopropane compounds in which the ethylene linker of a known amidine-type inhibitor 2 was replaced with chiral cyclopropane rings. The synthesis and biologic evaluation of these compounds revealed that the cis-(1S,2R) isomer 6 exhibited the most potent BACE1 inhibitory activity among them. X-ray structure analysis of the complex of 6 and BACE1 revealed that its unique binding mode is due to the apparent CH-π interaction between the rigid cyclopropane ring and the Tyr71 side chain. A derivatization study using 6 as a lead molecule led to the development of highly potent inhibitors in which the structure-activity relationship as well as the binding mode of the compounds clearly differ from those of known amidine-type inhibitors.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Ciclopropanos/síntesis química , Simulación del Acoplamiento Molecular , Pirimidinas/síntesis química , Cristalografía por Rayos X , Ciclopropanos/química , Entropía , Ensayo de Inmunoadsorción Enzimática , Fluorescencia , Humanos , Conformación Molecular , Unión Proteica , Pirimidinas/química , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
The P4 region of a series of oxamyl dipeptide caspase inhibitors was optimized by the combination of anti-apoptotic activity in the Jurkat/Fas (JFas) cellular assay and membrane permeability in the PAMPA assay. Two highly potent anti-apoptotic agents with moderate membrane permeability, 29 and 36, showed strong in vivo efficacy in a murine model of alpha-Fas-induced liver injury.
Asunto(s)
Inhibidores de Caspasas , Inhibidores de Cisteína Proteinasa/síntesis química , Hepatopatías/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Inhibidores de Cisteína Proteinasa/farmacología , Humanos , Células Jurkat , Ratones , Relación Estructura-Actividad , Receptor fasRESUMEN
(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-piperidin-1-yl]-1-hydroxyethyl]-3,4-dihydro-quinolin-2(1H)-one (compound A) is an NR2B selective N-methyl d-aspartate (NMDA) antagonist that has shown at least two polymorphs, forms I and II. In this report, we prepared two polymorphs, forms I and II and their crystal forms were identified and characterized by single crystal X-ray diffractometry, differential scanning calorimetry (DSC) and variable temperature powder X-ray diffractometry (VT-PXRD). The results of DSC and VT-PXRD suggested that compound A has at least three polymorphic forms: I, II and a new form III, and that forms II and III showed an enantiotropic relationship. We also performed single crystal X-ray analyses of specific conditions based on the results of VT-PXRD. The unit cell dimensions in crystallographic parameter and molecular arrangements of form I were quite different from forms II and III. Whereas, the crystal structures of forms II and III were similar with the exception of the C58-C59-C61-C62 torsion angle.
Asunto(s)
Antagonistas de Aminoácidos Excitadores/farmacología , Piperidinas/farmacología , Quinolonas/farmacología , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Isomerismo , Microscopía Electrónica de Rastreo , Modelos Moleculares , Conformación Molecular , Piperidinas/química , Quinolonas/química , Difracción de Rayos XRESUMEN
In drug discovery programs, predicting key example compounds in competitors' patent applications is important work for scientists working in the same or in related research areas. In general, medicinal chemists are responsible for this work, and they attempt to guess the identity of key compounds based on information provided in patent applications, such as biological data, scale of reaction, and/or optimization of the salt form for a particular compound. However, this is sometimes made difficult by the lack of such information. This paper describes a method for predicting key compounds in competitors' patent applications by using only structural information of example compounds. Based on the assumption that medicinal chemists usually carry out extensive structure--activity relationship (SAR) studies around key compounds, the method identifies compounds located at the centers of densely populated regions in the patent examples' chemical space, as represented by Extended Connectivity Fingerprints (ECFPs). For the validation of the method, a total of 30 patents containing structures of launched drugs were selected to test whether or not the method is able to predict key compounds (the launched drugs). In 17 out of the 30 patents (57%), the method was able to successfully predict the key compounds. The result indicates that our method could provide an alternative approach to predicting key compounds in cases where the conventional medicinal chemist's approach does not work well. This method could also be used as a complement to the traditional medicinal chemist's approach.
Asunto(s)
Química Farmacéutica , Simulación por Computador , Diseño de Fármacos , Patentes como Asunto , Relación Estructura-Actividad , Humanos , Análisis de Componente Principal , Reproducibilidad de los ResultadosRESUMEN
To ensure a continuing pipeline in pharmaceutical research, lead candidates must possess appropriate metabolic stability in the drug discovery process. In vitro ADMET (absorption, distribution, metabolism, elimination, and toxicity) screening provides us with useful information regarding the metabolic stability of compounds. However, before the synthesis stage, an efficient process is required in order to deal with the vast quantity of data from large compound libraries and high-throughput screening. Here we have derived a relationship between the chemical structure and its metabolic stability for a data set of in-house compounds by means of various in silico machine learning such as random forest, support vector machine (SVM), logistic regression, and recursive partitioning. For model building, 1952 proprietary compounds comprising two classes (stable/unstable) were used with 193 descriptors calculated by Molecular Operating Environment. The results using test compounds have demonstrated that all classifiers yielded satisfactory results (accuracy > 0.8, sensitivity > 0.9, specificity > 0.6, and precision > 0.8). Above all, classification by random forest as well as SVM yielded kappa values of approximately 0.7 in an independent validation set, slightly higher than other classification tools. These results suggest that nonlinear/ensemble-based classification methods might prove useful in the area of in silico ADME modeling.
Asunto(s)
Inteligencia Artificial , Microsomas Hepáticos/metabolismo , Simulación por Computador , Evaluación Preclínica de Medicamentos/métodos , Estabilidad de Medicamentos , Humanos , Modelos Logísticos , Valor Predictivo de las Pruebas , Relación Estructura-Actividad Cuantitativa , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
A novel potent NMDA-NR2B selective antagonist without the reactive metabolites formation issue was identified. Through this study, a close correlation between reactive metabolites formation and calculated HOMO energies of parent compounds was found.
Asunto(s)
Amidas/química , Amidas/farmacología , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Amidas/síntesis química , Amidas/metabolismo , Animales , Línea Celular , Glutatión/química , Humanos , Ratones , Estructura Molecular , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fenol/química , Fenoles/química , Relación Estructura-ActividadRESUMEN
(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone was identified as an orally active NR2B-subunit selective N-methyl-d-aspartate (NMDA) receptor antagonist. It has very high selectivity for NR2B subunits containing NMDA receptors versus the HERG-channel inhibition (therapeutic index=4200 vs NR2B binding IC(50)). This compound has improved pharmacokinetic properties compared to the prototype CP-101,606.
Asunto(s)
N-Metilaspartato/antagonistas & inhibidores , N-Metilaspartato/metabolismo , Dolor , Piperidinas/química , Quinolonas/química , Receptores de N-Metil-D-Aspartato/metabolismo , Animales , Citocromo P-450 CYP2D6/metabolismo , Inhibidores del Citocromo P-450 CYP2D6 , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Canales de Potasio Éter-A-Go-Go/metabolismo , Concentración 50 Inhibidora , Estructura Molecular , Dolor/tratamiento farmacológico , Piperidinas/farmacología , Quinolonas/farmacología , Ratas , Relación Estructura-ActividadRESUMEN
Novel NR2B antagonists with an amide tether were found by an approach to avoid pharmacophoric similarity to dofetilide. Structure-activity relationship investigation led to N-[cis-4-hydroxy-4-(5-hydroxypyridin-2-yl)cyclohexyl]-3-henylpropanamide as an orally active NR2B-subtype selective N-methyl-D-aspartate (NMDA) receptor antagonist with very weak HERG (human ether-a-go-go related gene) binding (IC(50)> 30 microM). This compound exhibited potent in vivo anti-allodynic activity in the mouse partial sciatic nerve ligation (PSL) model (minimum effective dose=10 mg/kg, po).