RESUMEN
The vitronectin receptor alpha(v)beta(3) has been identified as a promising potential target for the treatment of osteoporosis, diabetic retinopathy and cancer. We have recently reported 5-substituted indoles 3-[5-[2-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)ethoxy]indol-1-yl]-3-(3-pyridyl)propionic acid 3 and 3-[5-[2-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)ethoxy]indol-1-yl]-3-(3,4-methylenedioxyphenyl)propionic acid 4, as an original series of potent alpha(v)beta(3) antagonists with subnanomolar activity. Ligand-protein docking analyses have been performed to generate binding models of three different chemical classes of known alpha(v)beta(3) antagonists with alpha(v)beta(3). Results of this docking study suggested that indoles bearing the basic tetrahydronaphthyridine group at position 4 can easily adopt the correct binding conformation and should be as potent as our current 5-substituted indole leads 3 and 4. This hypothesis was nicely demonstrated by the synthesis of a series of 1,4-disubstituted indoles through a tandem of reactions involving: (i) the N-alkylation of indoles 15 and 22 with propargyl esters and cesium fluoride, and (ii) a Heck coupling reaction between 4-bromoindole and 7-vinyl-3,4-dihydro-2H-[1,8]naphthyridine-1-carboxylic acid tert-butyl ester 12, or (iii) a reductive amination involving the N-substituted-4-aminoindole 23 and the BOC-protected tetrahydro[1,8]naphthyridine aldehyde 13. Among the compounds assayed, 3-(3-pyridyl)-3-[4-[2-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)ethyl]indol-1-yl]propionic acid 21 showed the most promising activity on alpha(v)beta(3) (IC(50)=0.5 nM), and was found to have the same potency as our current leads 3 and 4, while maintaining selectivity over alpha(IIb)beta(IIIa). Moreover, based on the reasonable apparent permeability coefficient in an in vitro CACO-2 cell monolayer assay (P(app) apical/basolateral=2.2 x 10(-6)cm/s, P(app) basolateral/apical=2.5 x 10(-6)cm/s), compound 21 is expected to be absorbed through the intestine in human. Thus, 1,4-disubstituted indole 21 represents a new lead for this novel class of conformationally restricted alpha(v)beta(3) antagonists. Additionally, this study validates the pharmacophore model previously postulated and provides an improved basis for further structure-based drug design in the field of alpha(v)beta(3).
Asunto(s)
Indoles/síntesis química , Indoles/farmacología , Integrina alfaVbeta3/antagonistas & inhibidores , Diseño de Fármacos , Ensayo de Inmunoadsorción Enzimática , Humanos , Indicadores y Reactivos , Indoles/química , Integrina alfa5beta1/antagonistas & inhibidores , Integrinas/antagonistas & inhibidores , Ligandos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Glicoproteína IIb de Membrana Plaquetaria/efectos de los fármacos , Receptores de Vitronectina/antagonistas & inhibidores , Relación Estructura-Actividad , Difracción de Rayos XRESUMEN
The binding of lead compounds and drugs to human serum albumin (HSA) is a ubiquitous problem in drug discovery since it modulates the availability of the leads and drugs to their intended target, which is linked to biological efficacy. In our continuing efforts to identify small molecule alpha(V)beta(3) and alpha(V)beta(5) dual antagonists, we recently reported indoles 2-4 as potent and selective alpha(V)beta(3)/alpha(V)beta(5) antagonists with good oral bioavailability profile. In spite of subnanomolar binding affinity of these compounds to human alpha(V)beta(3) and alpha(V)beta(5) integrins, high HSA binding (96.5-97.3%) emerged as a limiting feature for these leads. Structure-activity HSA binding data of organic acids reported in the literature have demonstrated that the incorporation of polar groups into a given molecule can dramatically decrease the affinity toward HSA. We sought to apply this strategy by examining the effects of such modifications in both the central core constrain and the substituent beta to the carboxylate. Most of these derivatives were prepared in good yields through a cesium fluoride-catalyzed coupling reaction. This reaction was successful with a variety of nitrogen-containing scaffolds (20, 33, and 43) and selected acetylenic derivatives (16, 19, and 34). Among the compounds synthesized, the 3-[5-[2-(5,6,7,8-tetrahydro [1,8]naphthyridin-2-yl)ethoxy]indol-1-yl]-3-[5-(N,N-dimethylaminomethyl)-3-pyridyl]propionic acid (25) was found to be the most promising derivative within this novel series with a subnanomolar affinity for both alpha(v)beta(3) and alpha(v)beta(5) (IC(50) = 0.29 and 0.16 nM, respectively), similar to our initial lead receptor antagonists 2-4, and exhibiting a low HSA protein binding (40% bound, K(d) = 1.1+/-0.4 x 10(3) microM) and an improved in vitro stability profile toward human and mouse microsomes (99.9% and 98.7% remaining after 10 min). Moreover, the selectivity of 25 toward alpha(5)beta(1) and IIbIIIa integrins was perfectly maintained when compared to the parent leads 2-4. Thus, compound 25 was selected as a new lead with improved drug-like properties for further evaluations in the field of oncology and osteoporosis.
Asunto(s)
Integrina alfaVbeta3/antagonistas & inhibidores , Integrinas/antagonistas & inhibidores , Receptores de Vitronectina/antagonistas & inhibidores , Albúmina Sérica/metabolismo , Alquinos/síntesis química , Alquinos/química , Bencimidazoles/química , Esterificación , Humanos , Hipoxantinas/síntesis química , Hipoxantinas/química , Indoles/síntesis química , Indoles/química , Estructura Molecular , Propionatos/síntesis química , Propionatos/química , Unión Proteica , Relación Estructura-ActividadRESUMEN
HDM2 binds to an alpha-helical transactivation domain of p53, inhibiting its tumor suppressive functions. A miniaturized thermal denaturation assay was used to screen chemical libraries, resulting in the discovery of a novel series of benzodiazepinedione antagonists of the HDM2-p53 interaction. The X-ray crystal structure of improved antagonists bound to HDM2 reveals their alpha-helix mimetic properties. These optimized molecules increase the transcription of p53 target genes and decrease proliferation of tumor cells expressing wild-type p53.
Asunto(s)
Benzodiazepinas/síntesis química , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/agonistas , Benzodiazepinas/química , Benzodiazepinas/farmacología , Sitios de Unión , Línea Celular Tumoral , Técnicas Químicas Combinatorias , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Imitación Molecular , Estructura Molecular , Proteínas Proto-Oncogénicas c-mdm2 , Estereoisomerismo , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/biosíntesisRESUMEN
A series of 2-acylaminothiophene-3-carboxamides has been identified which exhibit potent inhibitory activity against the FLT3 tyrosine kinase. Compound 44 inhibits the isolated enzyme (IC50 = 0.027 microM) and blocks the proliferation of MV4-11 cells (IC50 = 0.41 microM). Structure-activity relationship studies within this series are described in the context of a proposed binding model within the ATP binding site of the enzyme.
Asunto(s)
Amidas/química , Amidas/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Tiofenos/química , Tirosina Quinasa 3 Similar a fms/antagonistas & inhibidores , Sitios de Unión , Línea Celular , Modelos Moleculares , Estructura Molecular , Relación Estructura-Actividad , Tirosina Quinasa 3 Similar a fms/química , Tirosina Quinasa 3 Similar a fms/metabolismoRESUMEN
Small molecule antagonists of protein-protein interactions represent a particular challenge for pharmaceutical discovery. One approach to finding molecules that can disrupt these interactions is to seek mimics of common protein structure motifs. We present an analysis of how molecules based on the 1,4-benzodiazepine-2,5-dione scaffold serve to mimic the side-chains presented by the hydrophobic face of two turns of an alpha-helix derived from the tumor suppressor protein p53, and thus antagonize the HDM2-p53 protein-protein binding interaction.
Asunto(s)
Benzodiazepinas/química , Diseño de Fármacos , Imitación Molecular , Mapeo de Interacción de Proteínas , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/metabolismo , Benzodiazepinas/farmacología , Humanos , Estructura Secundaria de Proteína/efectos de los fármacos , Proteínas Proto-Oncogénicas c-mdm2/química , Proteína p53 Supresora de Tumor/químicaRESUMEN
The 1,4-benzodiazepine-2,5-dione is a suitable template to disrupt the interaction between p53 and Hdm2. The development of an enantioselective synthesis disclosed the stereochemistry of the active enantiomer. An in vitro p53 peptide displacement assay identified active compounds. These activities were confirmed in several cell-based assays including induction of the p53 regulated gene (PIG-3) and caspase activity.
Asunto(s)
Benzodiazepinas/química , Benzodiazepinas/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Benzodiazepinas/síntesis química , Caspasas/metabolismo , Línea Celular Tumoral , Cristalografía por Rayos X , Inhibidores Enzimáticos/química , Humanos , Enlace de Hidrógeno , Modelos Moleculares , Estructura Molecular , Mutación/genética , Proteínas Proto-Oncogénicas c-mdm2/química , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Estereoisomerismo , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
The disruption of the p53-Hdm2 protein-protein interaction induces cell growth arrest and apoptosis. We have identified the 1,4-benzodiazepine-2,5-dione scaffold as a suitable template for inhibiting this interaction by binding to the Hdm2 protein. Several compounds have been made with improved potency, solubility, and cell-based activities.
Asunto(s)
Benzodiazepinas/farmacología , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Benzodiazepinas/síntesis química , Benzodiazepinas/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Estereoisomerismo , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Guided by structure-based drug design, modification of the 1,4-benzodiazepin-2,5-dione lead compound 1 resulted in the discovery of 19, a potent and orally bioavailable antagonist of the HDM2-p53 protein-protein interaction (FP IC50 = 0.7 microM, F approximately 100%).
Asunto(s)
Benzodiazepinas/química , Diseño de Fármacos , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/metabolismo , Alquilación , Animales , Benzodiazepinas/síntesis química , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Humanos , Ratones , Modelos Moleculares , Estructura Molecular , Ácidos Pentanoicos/química , Unión Proteica , Proteínas Proto-Oncogénicas c-mdm2/química , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/químicaRESUMEN
We describe the synthesis and structure/activity relationship of RGD mimetics that are potent inhibitors of the integrin alpha(v)beta3. Indol-1-yl propionic acids containing a variety of basic moieties at the 5-position, as well as substitutions alpha and beta to the carboxy terminus were synthesized and evaluated. Novel compounds with improved potency have been identified.
Asunto(s)
Integrina alfaVbeta3/antagonistas & inhibidores , Propionatos/farmacología , Indoles/química , Imitación Molecular , Oligopéptidos/química , Propionatos/química , Relación Estructura-ActividadRESUMEN
A library of 1,4-benzodiazepine-2,5-diones was screened for binding to the p53-binding domain of HDM2 using Thermofluor, a miniaturized thermal denaturation assay. The hits obtained were shown to bind to HDM2 in the p53-binding pocket using a fluorescence polarization (FP) peptide displacement assay. The potency of the series was optimized, leading to sub-micromolar antagonists of the p53-HDM2 interaction.
Asunto(s)
Benzodiazepinas/síntesis química , Benzodiazepinas/farmacología , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Sitios de Unión , Técnicas Químicas Combinatorias , Polarización de Fluorescencia , Humanos , Concentración 50 Inhibidora , Proteínas Nucleares/antagonistas & inhibidores , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-mdm2 , Relación Estructura-Actividad , Proteína p53 Supresora de Tumor/antagonistas & inhibidoresRESUMEN
Crystallographic analysis of ligands bound to HDM2 suggested that 7-substituted 1,4-diazepine-2,5-diones could mimic the alpha-helix of p53 peptide and may represent a promising scaffold to develop HDM2-p53 antagonists. To verify this hypothesis, we synthesized and biologically evaluated 5-[(3S)-3-(4-chlorophenyl)-4-[(R)-1-(4-chlorophenyl)ethyl]-2,5-dioxo-7-phenyl-1,4-diazepin-1-yl]valeric acid (10) and 5-[(3S)-7-(2-bromophenyl)-3-(4-chlorophenyl)-4-[(R)-1-(4-chlorophenyl)ethyl]-2,5-dioxo-1,4-diazepin-1-yl]valeric acid (11). Preliminary in vitro testing shows that 10 and 11 substantially antagonize the binding between HDM2 and p53 with an IC(50) of 13 and 3.6 microM, respectively, validating the modeling predictions. Taken together with the high cell permeability of diazepine 11 determined in CACO-2 cells, these results suggest that 1,4-diazepine-2,5-diones may be useful in the treatment of certain cancers.