RESUMO
Co-inhibitory immune receptors can contribute to T cell dysfunction in patients with cancer1,2. Blocking antibodies against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1) partially reverse this effect and are becoming standard of care in an increasing number of malignancies3. However, many of the other axes by which tumours become inhospitable to T cells are not fully understood. Here we report that V-domain immunoglobulin suppressor of T cell activation (VISTA) engages and suppresses T cells selectively at acidic pH such as that found in tumour microenvironments. Multiple histidine residues along the rim of the VISTA extracellular domain mediate binding to the adhesion and co-inhibitory receptor P-selectin glycoprotein ligand-1 (PSGL-1). Antibodies engineered to selectively bind and block this interaction in acidic environments were sufficient to reverse VISTA-mediated immune suppression in vivo. These findings identify a mechanism by which VISTA may engender resistance to anti-tumour immune responses, as well as an unexpectedly determinative role for pH in immune co-receptor engagement.
Assuntos
Antígenos B7/química , Antígenos B7/metabolismo , Glicoproteínas de Membrana/metabolismo , Linfócitos T/metabolismo , Animais , Anticorpos Bloqueadores/imunologia , Anticorpos Bloqueadores/farmacologia , Antígenos B7/antagonistas & inibidores , Antígenos B7/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Cristalografia por Raios X , Epitopos de Linfócito B/química , Epitopos de Linfócito B/imunologia , Feminino , Histidina/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Ligantes , Masculino , Glicoproteínas de Membrana/imunologia , Camundongos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos , Linfócitos T/citologia , Linfócitos T/imunologia , Microambiente Tumoral/imunologiaRESUMO
It is estimated that more than 170 million people are infected with hepatitis C virus (HCV) worldwide. Clinical trials have demonstrated that, for the first time in human history, the potential exists to eradicate a chronic viral disease using combination therapies that contain only direct-acting antiviral agents. HCV non-structural protein 5A (NS5A) is a multifunctional protein required for several stages of the virus replication cycle. NS5A replication complex inhibitors, exemplified by daclatasvir (DCV; also known as BMS-790052 and Daklinza), belong to the most potent class of direct-acting anti-HCV agents described so far, with in vitro activity in the picomolar (pM) to low nanomolar (nM) range. The potency observed in vitro has translated into clinical efficacy, with HCV RNA declining by ~3-4 log10 in infected patients after administration of single oral doses of DCV. Understanding the exceptional potency of DCV was a key objective of this study. Here we show that although DCV and an NS5A inhibitor analogue (Syn-395) are inactive against certain NS5A resistance variants, combinations of the pair enhance DCV potency by >1,000-fold, restoring activity to the pM range. This synergistic effect was validated in vivo using an HCV-infected chimaeric mouse model. The cooperative interaction of a pair of compounds suggests that NS5A protein molecules communicate with each other: one inhibitor binds to resistant NS5A, causing a conformational change that is transmitted to adjacent NS5As, resensitizing resistant NS5A so that the second inhibitor can act to restore inhibition. This unprecedented synergistic anti-HCV activity also enhances the resistance barrier of DCV, providing additional options for HCV combination therapy and new insight into the role of NS5A in the HCV replication cycle.
Assuntos
Antivirais/farmacologia , Compostos de Bifenilo/farmacologia , Farmacorresistência Viral/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Imidazóis/farmacologia , Proteínas não Estruturais Virais/metabolismo , Regulação Alostérica/efeitos dos fármacos , Animais , Carbamatos , Linhagem Celular , Sinergismo Farmacológico , Quimioterapia Combinada , Hepacivirus/metabolismo , Hepatite C/virologia , Hepatócitos/transplante , Humanos , Camundongos , Modelos Moleculares , Conformação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Estrutura Quaternária de Proteína/efeitos dos fármacos , Pirrolidinas , Reprodutibilidade dos Testes , Valina/análogos & derivados , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Replicação Viral/efeitos dos fármacosRESUMO
Naphthalene-linked P2-P4 macrocycles within a tri-peptide-based acyl sulfonamide chemotype have been synthesized and found to inhibit HCV NS3 proteases representing genotypes 1a and 1b with single digit nanomolar potency. The pharmacokinetic profile of compounds in this series was optimized through structural modifications along the macrocycle tether as well as the P1 subsite. Ultimately a compound with oral bioavailability of 100% in rat, and a long half-life in plasma was obtained. However, compounds in this macrocyclic series exhibited cardiac effects in an isolated rabbit heart model and for this reason further optimization efforts were discontinued.
Assuntos
Antivirais/química , Compostos Macrocíclicos/química , Naftalenos/química , Inibidores de Proteases/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Antivirais/farmacologia , Avaliação Pré-Clínica de Medicamentos , Meia-Vida , Coração/efeitos dos fármacos , Coração/fisiologia , Hepacivirus/efeitos dos fármacos , Hepacivirus/enzimologia , Compostos Macrocíclicos/farmacocinética , Compostos Macrocíclicos/farmacologia , Microssomos Hepáticos/metabolismo , Conformação Molecular , Inibidores de Proteases/farmacocinética , Inibidores de Proteases/farmacologia , Coelhos , Ratos , Proteínas não Estruturais Virais/metabolismoRESUMO
Alkoxyanthranilic acid derivatives have been identified to inhibit HCV NS5B polymerase, binding in an allosteric site located at the convergence of the palm and thumb regions. Information from co-crystal structures guided the structural design strategy. Ultimately, two independent structural modifications led to a similar shift in binding mode that when combined led to a synergistic improvement in potency and the identification of inhibitors with sub-micromolar HCV NS5B binding potency.
Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , ortoaminobenzoatos/farmacologia , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/metabolismo , ortoaminobenzoatos/síntese química , ortoaminobenzoatos/químicaRESUMO
A series of potent and novel acylsulfonamide-bearing triazines were synthesized and the structure-activity relationships (SARs) as HCV entry inhibitors were evaluated. This acylsulfonamide series was derived from an early lead, 4-(4-(1-(4-chlorophenyl)cyclopropylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-ylamino)benzoic acid wherein the carboxylic acid was replaced with an acylsulfonamide moiety. This structural modification provided a class of compounds which projected an additional vector off the terminus of the acylsulfonamide functionality as a means to drive activity. This effort led to the discovery of potent analogues within this series that demonstrated sub-nanomolar EC50 values in the HCV pseudotype particle (HCVpp) assay.
Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Fusão de Membrana/efeitos dos fármacos , Triazinas/farmacologia , Animais , Antivirais/química , Antivirais/farmacocinética , Hepacivirus/fisiologia , Humanos , Ratos , Relação Estrutura-Atividade , Triazinas/química , Triazinas/farmacocinéticaRESUMO
The synthesis, structure-activity relationship (SAR) data, and further optimization of the metabolic stability and pharmacokinetic (PK) properties for a previously disclosed class of cyclopropyl-fused indolobenzazepine HCV NS5B polymerase inhibitors are described. These efforts led to the discovery of BMS-961955 as a viable contingency backup to beclabuvir which was recently approved in Japan for the treatment of HCV as part of a three drug, single pill combination marketed as XimencyTM.
Assuntos
Antivirais/química , Antivirais/farmacologia , Benzazepinas/química , Benzazepinas/farmacologia , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/farmacocinética , Benzazepinas/farmacocinética , Cães , Haplorrinos , Hepacivirus/enzimologia , Hepacivirus/metabolismo , Hepatite C/virologia , Humanos , RNA Polimerase Dependente de RNA/antagonistas & inibidores , RNA Polimerase Dependente de RNA/metabolismo , Ratos , Proteínas não Estruturais Virais/metabolismoRESUMO
HCV infection is an urgent global health problem that has triggered a drive to discover therapies that specifically target the virus. BMS-791325 is a novel direct antiviral agent specifically targeting HCV NS5B, an RNA-dependent RNA polymerase. Robust viral clearance of HCV was observed in infected patients treated with BMS-791325 in combination with other anti-HCV agents in Phase 2 clinical studies. Biochemical and biophysical studies revealed that BMS-791325 is a time-dependent, non-competitive inhibitor of the polymerase. Binding studies with NS5B genetic variants (WT, L30S, and P495L) exposed a two-step, slow binding mechanism, but details of the binding mechanism differed for each of the polymerase variants. For the clinically relevant resistance variant (P495L), the rate of initial complex formation and dissociation is similar to WT, but the kinetics of the second step is significantly faster, showing that this variant impacts the final tight complex. The resulting shortened residence time translates into the observed decrease in inhibitor potency. The L30S variant has a significantly different profile. The rate of initial complex formation and dissociation is 7-10 times faster for the L30S variant compared with WT; however, the forward and reverse rates to form the final complex are not significantly different. The impact of the L30S variant on the inhibition profile and binding kinetics of BMS-791325 provides experimental evidence for the dynamic interaction of fingers and thumb domains in an environment that supports the formation of active replication complexes and the initiation of RNA synthesis.
Assuntos
Antivirais/química , Benzazepinas/química , Hepacivirus/enzimologia , Indóis/química , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Proteínas não Estruturais Virais/antagonistas & inibidores , Substituição de Aminoácidos , Antivirais/farmacologia , Benzazepinas/uso terapêutico , Hepatite C/tratamento farmacológico , Hepatite C/enzimologia , Humanos , Indóis/uso terapêutico , Mutação de Sentido Incorreto , Ligação Proteica , RNA Viral/biossíntese , RNA Polimerase Dependente de RNA/química , RNA Polimerase Dependente de RNA/metabolismo , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismoRESUMO
BMS-791325 is an allosteric inhibitor that binds to thumb site 1 of the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase. BMS-791325 inhibits recombinant NS5B proteins from HCV genotypes 1, 3, 4, and 5 at 50% inhibitory concentrations (IC50) below 28 nM. In cell culture, BMS-791325 inhibited replication of HCV subgenomic replicons representing genotypes 1a and 1b at 50% effective concentrations (EC50s) of 3 nM and 6 nM, respectively, with similar (3 to 18 nM) values for genotypes 3a, 4a, and 5a. Potency against genotype 6a showed more variability (9 to 125 nM), and activity was weaker against genotype 2 (EC50, 87 to 925 nM). Specificity was demonstrated by the absence of activity (EC50s of >4 µM) against a panel of mammalian viruses, and cytotoxic concentrations (50%) were >3,000-fold above the HCV EC50. Resistance substitutions selected by BMS-791325 in genotype 1 replicons mostly mapped to a single site, NS5B amino acid 495 (P495A/S/L/T). Additive or synergistic activity was observed in combination studies using BMS-791325 with alfa interferon plus ribavirin, inhibitors of NS3 protease or NS5A, and other classes of NS5B inhibitor (palm site 2-binding or nucleoside analogs). Plasma and liver exposures in vivo in several animal species indicated that BMS-791325 has a hepatotropic disposition (liver-to-plasma ratios ranging from 1.6- to 60-fold across species). Twenty-four hours postdose, liver exposures across all species tested were ≥ 10-fold above the inhibitor EC50s observed with HCV genotype 1 replicons. These findings support the evaluation of BMS-791325 in combination regimens for the treatment of HCV. Phase 3 studies are ongoing.
Assuntos
Antivirais/farmacologia , Benzazepinas/farmacologia , Hepacivirus/enzimologia , Indóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Regulação Alostérica , Animais , Antivirais/química , Benzazepinas/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cães , Farmacorresistência Viral , Quimioterapia Combinada , Genótipo , Hepacivirus/efeitos dos fármacos , Humanos , Indóis/química , Interferon-alfa/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Replicon/efeitos dos fármacos , Ribavirina/farmacologia , Células VeroRESUMO
Purpose: In recent years, exosomes have been proved to be used to treat many diseases. However, due to the lack of uniform quality control standards for exosomes, the safety of exosomes is still a problem to be solved, especially now more and more exosomes are used in clinical trials, and its non-clinical safety evaluation is particularly important. However, there is no safety evaluation standard for exosomes at present. Therefore, this study will refer to the evaluation criteria of therapeutic biological products, adopt non-human primates to evaluate the non-clinical safety of human umbilical cord mesenchymal stem cell exosomes from the general pharmacology and immunotoxicity, aiming at establishing a safety evaluation system of exosomes and providing reference for the clinical application of exosomes in the future. Methods: 3.85 × 1012 exosomes derived from human umbilical cord mesenchymal stem cells were injected into cynomolgus monkeys intravenously. The changes of general clinical conditions, hematology, immunoglobulin, Th1/Th2 cytokines, T lymphocytes and B lymphocytes, and immune organs were observed before and within 14 days after injection. Results: The results showed that exosomes did not have obvious pathological effects on the general clinical conditions, blood, coagulation function, organ coefficient, immunoglobulin, Th1/Th2 cytokines, lymphocytes, major organs, and major immune organs (spleen, thymus, bone marrow) of cynomolgus monkeys. However, the number of granulocyte-macrophage colonies in exosomes group was significantly higher than that in control group. Conclusion: To sum up, the general pharmacological results and immunotoxicity results showed that the injection of 3.85 × 1012 exosomes may have no obvious adverse reactions to cynomolgus monkeys. This dose of exosomes is relatively safe for treatment, which provides basis research for non-clinical safety evaluation of exosomes and provides reliable research basis for future clinical application of exosomes.
Assuntos
Exossomos , Macaca fascicularis , Células-Tronco Mesenquimais , Cordão Umbilical , Animais , Exossomos/química , Células-Tronco Mesenquimais/citologia , Humanos , Cordão Umbilical/citologia , Masculino , Feminino , Citocinas/metabolismoRESUMO
Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) that causes demyelination, neuronal damage and white matter loss, but there is still no known cure. Exosomes are 30-200 nm-sized double-layered membrane vesicles that can easily cross the blood-brain barrier (BBB). Exosomes from umbilical cord mesenchymal stem cellsï¼UMSCsï¼ have been found to treat experimental autoimmune encephalomyelitis (EAE) through the action of anti-inflammatory and immunomodulatory, but its clinical translation has been hampered by their inefficacious accumulation in CNS. Therefore, we developed a TAxI-exos, also known as a TAxI-peptide-chimeric UMSC-exos, for CNS-specific accumulation and curative effect in EAE. We used the EAE model in vivo as well as active T cell and BV-2 cell models in vitro to explore the efficacy and mechanisms. Exosomes from UMSCs with TAxI or DiR labels were given to EAE mice in one dosage (150 g) prior to the peak at day 15. The mice were sacrificed on day 30 so that spinal cords, spleens, and blood could be taken for analysis of demyelination, inflammation, microglia, T-cell subset proportions, and inflammatory cytokine expression. In vitro, PBMCs and splenocytes isolated from healthy C57BL/6 mice were activated and incubated with 0.15 mg/mL of UMSC-exos or TAxI-exos for immune mechanism investigations. Activated BV-2 cells were used to investigate the targeting and controlling polarization ability and mechanism of UMSC-exos and TAxI-exos. As expected, TAxI-exos exhibited significantly greater therapeutic action in EAE mice than UMSC-exos due to their improved targeting-ability. The medication reduced T-cell subset proportions and inflammation, reduced active-microglia proportions and promoted M1 to M2 microglial cell polarization through TNF pathway, upregulated IL-4, IL-10, TGF-ß, and IDO-1 expression, and downregulated IL-2, IL-6, IL-17A, IFN-γ, and TNF-α. The CNS-targeting properties of TAxI-exos and their capacity to inhibit degenerative processes in EAE mice have considerable potential therapeutic value for MS and other CNS illnesses.
Assuntos
Encefalomielite Autoimune Experimental , Exossomos , Esclerose Múltipla , Camundongos , Animais , Exossomos/metabolismo , Camundongos Endogâmicos C57BL , Sistema Nervoso Central , Inflamação/metabolismo , Citocinas/metabolismo , Esclerose Múltipla/terapia , Esclerose Múltipla/metabolismoRESUMO
Presented here are initial structure-activity relationship (SAR) studies on a series of novel heteroaryl fused tetracyclic indole-based inhibitors of the hepatitis C viral polymerase, NS5B. The introduction of alternative heterocyclic moieties into the indolo-fused inhibitor class significantly expands the reported SAR and resulted in the identification of pyridino analogs, typified by compounds 44 and 45 that displayed excellent potency against the NS5B polymerase of both HCV 1a and HCV 1b genotypes.
Assuntos
Amidas/química , Hepacivirus/efeitos dos fármacos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Regulação Alostérica , Amidas/farmacologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Compostos Heterocíclicos/farmacologia , Humanos , Indóis/química , Indóis/farmacologia , Concentração Inibidora 50 , Relação Estrutura-AtividadeRESUMO
Kinase inhibition continues to be a major focus of pharmaceutical research and discovery due to the central role of these proteins in the regulation of cellular processes. One family of kinases of pharmacological interest, due to its role in activation of immunostimulatory pathways, is the Janus kinase family. Small molecule inhibitors targeting the individual kinase proteins within this family have long been sought-after therapies. High sequence and structural similarity of the family members makes selective inhibitors difficult to identify but critical because of their inter-related multiple cellular regulatory pathways. Herein, we describe the identification of inhibitors of the important Janus kinase, TYK2, a regulator of type I interferon response. In addition, the biochemical and structural confirmation of the direct interaction of these small molecules with the TYK2 pseudokinase domain is described and a potential mechanism of allosteric regulation of TYK2 activity through stabilization of the pseudokinase domain is proposed.
Assuntos
Janus Quinases , TYK2 Quinase , Regulação Alostérica , Janus Quinases/metabolismo , Transdução de Sinais , TYK2 Quinase/química , TYK2 Quinase/metabolismoRESUMO
The objective of the present study was to clarify the expression characteristics of long noncoding RNA (lncRNA) FGD5 antisense RNA 1 (FGD5AS1) in pancreatic cancer, as well as its biological function and underlying mechanism. Reverse transcriptionquantitative polymerase chain reaction (RTqPCR) was utilized for the detection of FGD5AS1 and microRNA (miR)577 expression levels in pancreatic cancer tissues. Transfection was performed to upregulate or downregulate FGD5AS1 in pancreatic cancer cell lines. MTT and Transwell assays were then utilized to detect the proliferation, migration and invasion of cancer cells, respectively. Subsequently, dualluciferase reporter gene assay, RNA immunoprecipitation assay, RNA pulldown assay, RTqPCR, western blotting, and Pearson's correlation analysis were employed to confirm the regulatory relationships among FGD5AS1, miR577, lowdensity lipoprotein receptorrelated protein 6 (LRP6) and ßcatenin. Western blotting was employed to determine the expression levels of Axin2, cyclin D1 and cMyc. The expression level of FGD5AS1 was upregulated in pancreatic cancer tissues and cell lines. FGD5AS1 knockdown inhibited pancreatic cancer cell proliferation, migration and invasion. By contrast, miR577 was significantly inhibited in pancreatic cancer cells and tissues; its downregulation promoted pancreatic cancer cell proliferation, migration and invasion, and reversed the effects of FGD5AS1 knockdown on pancreatic cancer cells. In addition, it was revealed that miR577 was a target of FGD5AS1, and FGD5AS1 could modulate the expression levels of LRP6, ßcatenin, Axin2, cyclin D1 and cMyc via suppressing miR577. In conclusion, in pancreatic cancer, highly expressed FGD5AS1 activated the Wnt/ßcatenin signaling and promoted cancer cell proliferation, migration and invasion via suppression of miR577.
Assuntos
Fatores de Troca do Nucleotídeo Guanina/genética , MicroRNAs/genética , Neoplasias Pancreáticas/genética , RNA Antissenso/genética , RNA Longo não Codificante/genética , Via de Sinalização Wnt , beta Catenina/genética , Adulto , Idoso , Regulação para Baixo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oncogenes , Regulação para Cima , Adulto JovemRESUMO
Preannealed homopolymeric DNAs or RNAs are often used as templates and/or primers to characterize activities of DNA or RNA-dependent RNA polymerases. Based on the calculated melting temperatures (T(m) values), however, poly(A)/oligo(dT(12-18)) is not expected to form stable duplexes. To determine this, we compared the enzymatic activity of hepatitis C virus polymerase using poly(A)/oligo(dT(12)) that were or were not preannealed. No significant differences were observed. These results suggest that it is not necessary to perform preannealing reactions for poly(A) and oligo(dT(12)), making it possible to characterize mechanism of inhibition of NS5B inhibitors against either template RNA poly(A) or primer oligo(dT(12)) independently.
Assuntos
Primers do DNA/metabolismo , Hepacivirus/enzimologia , Poli A/metabolismo , Poli T/metabolismo , Proteínas não Estruturais Virais/metabolismo , Primers do DNA/química , Primers do DNA/genética , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Poli A/genética , Poli T/genética , Relação Estrutura-Atividade , Moldes Genéticos , Proteínas não Estruturais Virais/antagonistas & inibidoresRESUMO
Described herein is the initial optimization of (+/-) N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamide (1), a hit discovered in a high throughput screen run against the NS5B polymerase enzyme of the hepatitis C virus. This effort resulted in the identification of (S)-N-sec-butyl-6-((R)-3-(4-(trifluoromethoxy)benzylcarbamoyl)-4-(4-(trifluoromethoxy)phenylsulfonyl)piperazin-1-yl)pyridazine-3-carboxamide (2), that displayed potent replicon activities against HCV genotypes 1b and 1a (EC(50) 1b/1a=7/89 nM).
Assuntos
Amidas/farmacologia , Inibidores Enzimáticos/farmacologia , Hepacivirus , Proteínas não Estruturais Virais/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Domínio Catalítico , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/química , Hepacivirus/enzimologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Piperazina , Piperazinas/síntese química , Piperazinas/química , Piperazinas/farmacologia , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Herein we report the identification and evaluation of a novel series of (E)-3-(1-cyclohexyl-1H-pyrazol-3-yl)-2-methylacrylic acid derivatives identified from a deannulation study performed on the reported benzimidazole NS5B inhibitor, 1. This resulted in the identification of (E)-3-(2-(4-((4'-cyano-4-(4-hydroxypiperidine-1-carbonyl)biphenyl-2-yl)methoxy)phenyl)-1-cyclohexyl-1H-imidazol-4-yl)-2-methylacrylic acid (11) as a potent inhibitor of NS5B. Potential pathways for the further optimization of this series are suggested.
Assuntos
Hepacivirus/efeitos dos fármacos , Metacrilatos/síntese química , Metacrilatos/farmacologia , Pirazóis/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Humanos , Concentração Inibidora 50 , Metacrilatos/química , Modelos Moleculares , Estrutura Molecular , Teoria Quântica , Proteínas não Estruturais Virais/químicaRESUMO
Structure based rationales for the activities of potent N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamide inhibitors of the hepatitis C viral polymerase are described herein. These compounds bind to the hepatitis C virus non-structural protein 5B (NS5B), and co-crystal structures of select examples from this series with NS5B are reported. Comparison of co-crystal structures of a potent analog with both NS5B genotype 1a and genotype 1b provides a possible explanation for the genotype-selectivity observed with this compound class and suggests opportunities for the further optimization of the series.
Assuntos
Amidas/química , Antivirais/química , Inibidores Enzimáticos/química , Hepacivirus/enzimologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Amidas/síntese química , Amidas/farmacologia , Antivirais/síntese química , Antivirais/farmacologia , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Hepacivirus/efeitos dos fármacos , Proteínas não Estruturais Virais/metabolismoRESUMO
Herein, we present initial SAR studies on a series of bridged 2-arylindole-based NS5B inhibitors. The introduction of bridging elements between the indole N1 and the ortho-position of the 2-aryl moiety resulted in conformationally constrained heterocycles that possess multiple additional vectors for further exploration. The binding mode and pharmacokinetic (PK) properties of select examples, including: 13-cyclohexyl-6-oxo-6,7-dihydro-5H-indolo[2,1-d][1,4]benzodiazepine-10-carboxylic acid (7) (IC(50)=0.07 µM, %F=18), are reported.
Assuntos
Ativação Enzimática/efeitos dos fármacos , Hepacivirus/enzimologia , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/farmacologia , Indóis/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Desenho de Fármacos , Compostos Heterocíclicos/química , Concentração Inibidora 50 , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Three synthetic approaches have been developed that allow efficient access to novel heteroaryl fused indole ring systems, including: 7,8,9,10-tetrahydro-6H-azepino[1,2-a]indoles, 4-oxo-2,3-dihydro-1H-[1,4]diazepino[1,7-a]indoles and 1,2,4,5-tetrahydro-[1,4]oxazepino[4,5-a]indoles. Each strategy is fully exemplified and the relative merits and limitations of the approaches are discussed. The hepatitis C virus (HCV) non-structural 5B (NS5B) polymerase inhibitory activities of select examples from each molecular class are briefly presented.
Assuntos
Indóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Técnicas de Química Sintética , Indóis/síntese química , Indóis/química , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The discovery of a pan-genotypic hepatitis C virus (HCV) NS3/4A protease inhibitor based on a P1-P3 macrocyclic tripeptide motif is described. The all-carbon tether linking the P1-P3 subsites of 21 is functionalized with alkyl substituents, which are shown to effectively modulate both potency and absorption, distribution, metabolism, and excretion (ADME) properties. The CF3Boc-group that caps the P3 amino moiety was discovered to be an essential contributor to metabolic stability, while positioning a methyl group at the C1 position of the P1' cyclopropyl ring enhanced plasma trough values following oral administration to rats. The C7-fluoro, C6-CD3O substitution pattern of the P2* isoquinoline heterocycle of 21 was essential to securing the targeted potency, pharmacokinetic (PK), and toxicological profiles. The C6-CD3O redirected metabolism away from a problematic pathway, thereby circumventing the time-dependent cytochrome P (CYP) 450 inhibition observed with the C6-CH3O prototype.