RESUMO
Gout is caused by elevated serum urate levels, which can be treated using inhibitors of the uric acid transporter, URAT1. Here, we characterize verinurad (RDEA3170), which is currently under evaluation for gout therapy. Verinurad specifically inhibits URAT1 with a potency of 25 nM. High affinity inhibition of uric acid transport requires URAT1 residues Cys-32, Ser-35, Phe-365 and Ile-481. Unlike other available uricosuric agents, the requirement for Cys-32 is unique to verinurad. Two of these residues, Ser-35 and Phe-365, are also important for urate transport kinetics. A URAT1 binding assay using radiolabeled verinurad revealed that distinct URAT1 inhibitors benzbromarone, sulfinpyrazone and probenecid all inhibit verinurad binding via a competitive mechanism. However, mutations made within the predicted transporter substrate channel differentially altered the potency for individual URAT1 inhibitors. Overall, our results suggest that URAT1 inhibitors bind to a common site in the core of the transporter and sterically hinder the transit of uric acid through the substrate channel, albeit with vastly different potencies and with differential interactions with specific URAT1 amino acids.
Assuntos
Gota/tratamento farmacológico , Gota/metabolismo , Hiperuricemia/tratamento farmacológico , Hiperuricemia/metabolismo , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Proteínas de Transporte de Cátions Orgânicos/antagonistas & inibidores , Uricosúricos/uso terapêutico , Adulto , Animais , Benzobromarona/farmacologia , Benzobromarona/uso terapêutico , Transporte Biológico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Concentração Inibidora 50 , Cinética , Masculino , Terapia de Alvo Molecular , Mutação , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/genética , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Ligação Proteica , Ratos , Ácido Úrico/sangue , Ácido Úrico/metabolismo , Uricosúricos/farmacologia , Adulto JovemRESUMO
Three new 5'-O-acyl tiazofurin derivatives 2-4 were synthesized and evaluated for their antiproliferative activity against different tumour cell lines as well as for their ability to induce apoptosis in C6 cells in vitro. Apart of the antitumour assays, the cell membrane permeation of 2-4 and their intracellular metabolism in C6 cells in vitro was also studied in order to evaluate their potential as possible tiazofurin bioisosteres or prodrugs.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Ribavirina/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Físico-Química , DNA de Neoplasias/biossíntese , DNA de Neoplasias/genética , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Marcação In Situ das Extremidades Cortadas , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Camundongos , Ribavirina/síntese química , Ribavirina/farmacologia , Espectrofotometria Infravermelho , Relação Estrutura-AtividadeRESUMO
Starting with 2-iodo-6-chloro-9-(beta-D-ribofuranosyl)purine, a library of more than 1,300 N2,N6-polysubstituted diaminopurine nucleosides was created. The starting material was condensed with a polystyrene monomethoxytrityl resin and a pool of primary and secondary amines was used to displace the 6-chloro atom with high regioselectivity. The 2-iodo was subsequently displaced by various primary amines. Nucleosides were cleaved from the resin with hexafluoroisopropanol solutions. A majority of compounds reached a purity of more than 80% without the need for any type of purification.
Assuntos
Nucleosídeos de Purina/síntese química , Espectroscopia de Ressonância Magnética , Poliestirenos/química , Nucleosídeos de Purina/químicaRESUMO
Several Toyocamycin (4) analogues were examined for their ability to inhibit HCV RNA in a replicon assay. Among the compounds examined 4-methylthio (18) and 5-carboxamide oxime derivatives (23 and 27) of Toyocamycin were found to have good activity and selectivity.
Assuntos
Antivirais/síntese química , Toiocamicina/síntese química , Antivirais/farmacologia , Hepatite C/tratamento farmacológico , Hepatite C/metabolismo , Hepatite C/virologia , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Nucleosídeos de Pirimidina/química , Pirimidinas/química , Pirróis/química , RNA Polimerase Dependente de RNA/antagonistas & inibidores , RNA Polimerase Dependente de RNA/metabolismo , Toiocamicina/análogos & derivados , Toiocamicina/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/metabolismoRESUMO
A new series of heterobase-modified 2'-C-methyl ribonucleosides was synthesized and tested as inhibitors of hepatitis C virus (HCV) RNA replication. The nucleosides showed a weak inhibitory activity in a HCV replicon system (EC(50)=92 microM) and did not exhibit any cytotoxicity (CC(50)>300 microM). Cyclic monophosphate (cMP) prodrugs of the same nucleosides were synthesized and also tested in the HCV replicon system. Prodrugs exhibited strong potency (EC(50)=0.008 microM) without significant cytotoxicity (CC(50)>50 microM).
Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Química Farmacêutica/métodos , Hepacivirus/genética , Hepatite C/tratamento farmacológico , Nucleotídeos Cíclicos/química , Pró-Fármacos/síntese química , Ribonucleosídeos/química , Replicação Viral/efeitos dos fármacos , Desenho de Fármacos , Humanos , Modelos Químicos , Conformação MolecularRESUMO
A series of 6-hydrazinopurine 2'-methyl ribonucleosides was synthesized and tested for its inhibitory activity against the hepatitis C virus (HCV). The lack of antiviral activity of these nucleosides was associated with a poor affinity for adenosine kinase, which prompted us to synthesize several of their 5'-monophosphate prodrugs. Some of these prodrugs exhibited more than 1000-fold improvement in anti-HCV activity when compared to their parent nucleosides (EC(50) of 24 nM vs 92 microM for the parent).
Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Hepacivirus/genética , Hepatite C/tratamento farmacológico , Fosfatos/química , Ribonucleosídeos/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos , Química Farmacêutica/métodos , Desenho de Fármacos , Humanos , Modelos Químicos , Conformação Molecular , Pró-FármacosRESUMO
Isothiazole analogs were discovered as a novel class of active-site inhibitors of HCV NS5B polymerase. The best compound has an IC(50) of 200 nM and EC(50) of 100 nM, which is a significant improvement over the starting inhibitor (1). The X-ray complex structure of 1 with HCV NS5B was obtained at a resolution of 2.2A, revealing that the inhibitor is covalently linked with Cys 366 of the 'primer-grip'. Furthermore, it makes considerable contacts with the C-terminus, beta-loop, and more importantly, to the active-site of the enzyme. The uniqueness of this binding mode offers a new insight for the rational design of novel inhibitors for HCV NS5B polymerase.
Assuntos
Antivirais/química , Antivirais/farmacologia , Tiazóis/química , Tiazóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Sítios de Ligação/efeitos dos fármacos , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Conformação Molecular , Conformação ProteicaRESUMO
A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 isolates. Several of these compounds exhibited potent antiviral activities against efavirenz- and nevirapine-resistant viruses, containing K103N and/or Y181C mutations or Y188L mutation. Triazoles were first synthesized from commercially available substituted phenylthiosemicarbazides, then from isothiocyanates, and later by condensing the desired substituted anilines with thiosemicarbazones.
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Transcriptase Reversa do HIV/antagonistas & inibidores , Triazóis/química , Triazóis/farmacologia , Inibidores Enzimáticos/síntese química , Transcriptase Reversa do HIV/metabolismo , HIV-1/efeitos dos fármacos , HIV-1/enzimologia , Estrutura Molecular , Nucleosídeos/síntese química , Nucleosídeos/química , Nucleosídeos/farmacologia , Relação Estrutura-Atividade , Triazóis/síntese químicaRESUMO
Ten new beta-D-ribofuranosyl and 2'-beta-C-methyl-beta-D-ribofuranosyl triciribine derivatives 4-13 with various N4 and 6-N substituents on the tricyclic ring were synthesized from the corresponding toyocamycin and new 2'-beta-C-methyl toyocamycin derivatives. The inhibitory studies of these compounds in the HCV replicon assay reveal that some of them possess interesting anti-HCV properties with low cytotoxicity.