RESUMEN
HCV NS5B RNA-dependent RNA polymerase (NS5B) is essential for viral replication and is therefore considered a target for antiviral drug development. From our ongoing screening effort in the search for new anti-HCV agents, a novel inhibitor 1 with low microM activity against the HCV NS5B polymerase was identified. SAR analysis indicated the optimal substitution pattern required for activity, for example, carboxylic acid group at 2-position of thiophene ring. We describe the steps taken to identify and solve the bioactive conformation of derivative 6 through the use of the transferred NOE method (trNOE).
Asunto(s)
Antivirales/síntesis química , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Sulfonamidas/síntesis química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/química , Humanos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular , Piridinas/química , ARN Polimerasa Dependiente del ARN/química , Relación Estructura-Actividad , Sulfonamidas/química , Tiofenos/química , Proteínas no Estructurales Virales/químicaRESUMEN
The discovery of a novel class of HCV NS5B polymerase inhibitors, 3-arylsulfonylamino-5-phenyl-thiophene-2-carboxylic acids is described. SAR studies have yielded several potent inhibitors of HCV polymerase as well as of HCV subgenomic RNA replication in Huh-7 cells.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Hepacivirus/enzimología , ARN Viral/metabolismo , Sulfonamidas/farmacología , Tiofenos/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Ácidos Carboxílicos , Carcinoma Hepatocelular/química , Carcinoma Hepatocelular/enzimología , Carcinoma Hepatocelular/virología , Inhibidores Enzimáticos/química , Genoma Viral , Humanos , Neoplasias Hepáticas/química , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/virología , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Replicón/efectos de los fármacos , Relación Estructura-Actividad , Sulfonamidas/química , Tiofenos/química , Replicación Viral/efectos de los fármacosRESUMEN
Further SAR studies on the thiophene-2-carboxylic acids are reported. These studies led to the identification of a series of tertiary amides that show inhibition of both HCV NS5B polymerase in vitro and HCV subgenomic RNA replication in Huh-7 cells. Structural insights about the bioactive conformation of this class of molecules were deduced from a combination of modeling and transferred NOE (trNOE) studies.
Asunto(s)
Amidas/farmacología , Inhibidores Enzimáticos/farmacología , Hepacivirus/enzimología , ARN Viral/metabolismo , Tiofenos/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Amidas/química , Ácidos Carboxílicos , Carcinoma Hepatocelular/química , Carcinoma Hepatocelular/enzimología , Carcinoma Hepatocelular/virología , Inhibidores Enzimáticos/química , Genoma Viral , Humanos , Neoplasias Hepáticas/química , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/virología , Espectroscopía de Resonancia Magnética , Conformación Molecular , Estructura Molecular , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Replicón/efectos de los fármacos , Relación Estructura-Actividad , Tiofenos/química , Replicación Viral/efectos de los fármacosRESUMEN
Herein, we describe the structure-activity relationship (SAR) of N,N-disubstituted phenylalanine series of NS5B polymerase inhibitors of hepatitis C. The NS5B polymerase inhibitory activity of the most active compound exhibited an IC(50) of 2.7 microM.
Asunto(s)
Inhibidores Enzimáticos/química , Hepacivirus/enzimología , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Proteínas no Estructurales Virales/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Hepacivirus/efectos de los fármacos , Humanos , Relación Estructura-Actividad , Proteínas no Estructurales Virales/metabolismoRESUMEN
The HCV NS5B RNA dependent RNA polymerase plays an essential role in viral replication. The discovery of a novel class of inhibitors based on an N,N-disubstituted phenylalanine scaffold and structure-activity relationships studies to improve potency are described.
Asunto(s)
Antivirales/síntesis química , Inhibidores Enzimáticos/síntesis química , Hepacivirus/enzimología , Fenilalanina/análogos & derivados , Fenilalanina/síntesis química , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/química , Inhibidores Enzimáticos/química , Fenilalanina/química , Relación Estructura-ActividadRESUMEN
X-ray crystal structures of two non-nucleoside analogue inhibitors bound to hepatitis C virus NS5B RNA-dependent RNA polymerase have been determined to 2.0 and 2.9 A resolution. These noncompetitive inhibitors bind to the same site on the protein, approximately 35 A from the active site. The common features of binding include a large hydrophobic region and two hydrogen bonds between both oxygen atoms of a carboxylate group on the inhibitor and two main chain amide nitrogen atoms of Ser(476) and Tyr(477) on NS5B. The inhibitor-binding site lies at the base of the thumb domain, near its interface with the C-terminal extension of NS5B. The location of this inhibitor-binding site suggests that the binding of these inhibitors interferes with a conformational change essential for the activity of the polymerase.
Asunto(s)
Nucleósidos/química , Proteínas no Estructurales Virales/genética , Sitio Alostérico , Secuencia de Aminoácidos , Sitios de Unión , Unión Competitiva , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Enlace de Hidrógeno , Concentración 50 Inhibidora , Modelos Químicos , Modelos Moleculares , Datos de Secuencia Molecular , Nitrógeno , Oxígeno , Unión Proteica , Conformación Proteica , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Serina/química , Tirosina/químicaRESUMEN
Nucleoside phosphonates are widely used therapeutic agents with a broad spectrum of antiviral activity. However, only a few of them are reported to have antitumor activity. In this study, we show that a tetrahydrofuran phosphonate analogue of guanosine, (-)-2-R-dihydroxyphosphinoyl-5-(S)-(guanin-9'-ylmethyl) tetrahydrofuran (BCH-1868), previously reported as having antiviral activity, also displays antitumor activity. In vitro, BCH-1868 inhibited the proliferation of several murine and human cancer cell lines with IC50s in the microM range independently of the tissue type or the presence of multidrug resistance protein MRP/gp190. In vivo, BCH-1868 was active against a variety of human tumor xenograft models (Caki-1, HT-29, DU 145, COLO 205, and CCRF-CEM). In all tumors tested, a significant tumor growth inhibition was noted at 40-50 mg/kg (daily x 5), but no tumor regression was observed in the settings used. To better understand these results, we partially characterized, at the cellular level, the mechanism of action of this new cyclic nucleoside phosphonate and investigated its pharmacokinetic characteristics in mice. We showed that BCH-1868 exerts its antitumor activity by an inhibitory mechanism at the level of DNA polymerase a, resulting in arrest of DNA synthesis and a block of cell division at the S phase of the cell cycle. Low-circulating plasma concentration (Cmax = 87 microM; area under the curve = 1138 micromol x min/liters; after a bolus i.v. injection of 10 mg/kg) and rapid clearance of the drug (terminal half-life, t1/2 = 16 min) may contribute to the modest antitumor efficacy observed in vivo.
Asunto(s)
Antineoplásicos/farmacocinética , Antivirales/farmacología , Guanina/farmacocinética , Ácidos Fosfínicos/farmacocinética , Animales , Ciclo Celular , División Celular , ADN Polimerasa I/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Guanina/análogos & derivados , Humanos , Concentración 50 Inhibidora , Hígado/metabolismo , Ratones , Ratones Desnudos , Ratones SCID , Modelos Químicos , Trasplante de Neoplasias , Factores de Tiempo , Células Tumorales CultivadasRESUMEN
We have identified several nucleotide phosphonates demonstrating in vitro antiproliferative activity in several human cancer cell lines with IC(50) values in the microM range. The synthesis as well as structure-activity relationship are described.