RESUMO
The human bile salt export pump (BSEP) is a membrane protein expressed on the canalicular plasma membrane domain of hepatocytes, which mediates active transport of unconjugated and conjugated bile salts from liver cells into bile. BSEP activity therefore plays an important role in bile flow. In humans, genetically inherited defects in BSEP expression or activity cause cholestatic liver injury, and many drugs that cause cholestatic drug-induced liver injury (DILI) in humans have been shown to inhibit BSEP activity in vitro and in vivo. These findings suggest that inhibition of BSEP activity by drugs could be one of the mechanisms that initiate human DILI. To gain insight into the chemical features responsible for BSEP inhibition, we have used a recently described in vitro membrane vesicle BSEP inhibition assay to quantify transporter inhibition for a set of 624 compounds. The relationship between BSEP inhibition and molecular physicochemical properties was investigated, and our results show that lipophilicity and molecular size are significantly correlated with BSEP inhibition. This data set was further used to build predictive BSEP classification models through multiple quantitative structure-activity relationship modeling approaches. The highest level of predictive accuracy was provided by a support vector machine model (accuracy = 0.87, κ = 0.74). These analyses highlight the potential value that can be gained by combining computational methods with experimental efforts in early stages of drug discovery projects to minimize the propensity of drug candidates to inhibit BSEP.
Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/química , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Ácidos e Sais Biliares/antagonistas & inibidores , Ácidos e Sais Biliares/metabolismo , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Humanos , Relação Quantitativa Estrutura-AtividadeRESUMO
Purinergic receptor P2X3 has been linked to analgesia in a number of pre-clinical models of pain, and is expressed in the human pain perception pathway. Only few P2X3-selective antagonists have been reported to date. This Letter describes the SAR and in vivo analgesic profile of a novel scaffold of selective P2X3 antagonists.
Assuntos
Analgésicos/síntese química , Dor Crônica/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2/síntese química , Pirimidinonas/síntese química , Pirróis/síntese química , Receptores Purinérgicos P2X3/química , Analgésicos/administração & dosagem , Analgésicos/uso terapêutico , Animais , Dor Crônica/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Triagem em Larga Escala , Humanos , Injeções Espinhais , Injeções Subcutâneas , Antagonistas do Receptor Purinérgico P2/administração & dosagem , Antagonistas do Receptor Purinérgico P2/uso terapêutico , Pirimidinonas/administração & dosagem , Pirimidinonas/uso terapêutico , Pirróis/administração & dosagem , Pirróis/uso terapêutico , Ratos , Ratos Sprague-Dawley , Receptores Purinérgicos P2X3/metabolismo , Bibliotecas de Moléculas PequenasRESUMO
The metabolism of xenobiotics--and more specifically drugs--in the liver is a critical process controlling their half-life. Although there exist experimental methods, which measure the metabolic stability of xenobiotics and identify their metabolites, developing higher throughput predictive methods is an avenue of research. It is expected that predicting the chemical nature of the metabolites would be an asset for designing safer drugs and/or drugs with modulated half-lives. We have developed IMPACTS (In-silico Metabolism Prediction by Activated Cytochromes and Transition States), a computational tool combining docking to metabolic enzymes, transition state modeling, and rule-based substrate reactivity prediction to predict the site of metabolism (SoM) of xenobiotics. Its application to sets of CYP1A2, CYP2C9, CYP2D6, and CYP3A4 substrates and comparison to experts' predictions demonstrates its accuracy and significance. IMPACTS identified an experimentally observed SoM in the top 2 predicted sites for 77% of the substrates, while the accuracy of biotransformation experts' prediction was 65%. Application of IMPACTS to external sets and comparison of its accuracy to those of eleven other methods further validated the method implemented in IMPACTS.
Assuntos
Modelos Biológicos , Software , Xenobióticos/metabolismo , Humanos , Especificidade por SubstratoRESUMO
The design, synthesis, and biological evaluation of a series of HIV-1 protease inhibitors [(-)-6, (-)-7, (-)-23, (+)-24] based upon the 3,5,5-trisubstituted pyrrolin-4-one scaffold is described. Use of a monopyrrolinone scaffold leads to inhibitors with improved cellular transport properties relative to the earlier inhibitors based on bispyrrolinones and their peptide counterparts. The most potent inhibitor (-)-7 displayed 13% oral bioavailability in dogs. X-ray structure analysis of the monopyrrolinone compounds cocrystallized with the wild-type HIV-1 protease provided valuable information on the interactions between the inhibitors and the HIV-1 enzyme. In each case, the inhibitors assumed similar orientations for the P2'-P1 substituents, along with an unexpected hydrogen bond of the pyrrolinone NH with Asp225. Interactions with the S2 pocket, however, were not optimal, as illustrated by the inclusion of a water molecule in two of the three inhibitor-enzyme complexes. Efforts to increase affinity by displacing the water molecule with second and third generation inhibitors did not prove successful. Lack of success with this venture is a testament to the difficulty of accurately predicting the many variables that influence and build binding affinity. Comparison of the inhibitor positions in three complexes with that of Indinavir revealed displacements of the protease backbones in the enzyme flap region, accompanied by variations in hydrogen bonding to accommodate the monopyrrolinone ring. The binding orientation of the pyrrolinone-based inhibitors may explain their sustained efficacy against mutant strains of the HIV-1 protease enzyme as compared to Indinavir.
Assuntos
Carbamatos/síntese química , Inibidores da Protease de HIV/síntese química , Protease de HIV/química , Pirróis/síntese química , Animais , Disponibilidade Biológica , Carbamatos/química , Carbamatos/farmacocinética , Cristalografia por Raios X , Cães , Desenho de Fármacos , Protease de HIV/genética , Inibidores da Protease de HIV/química , Inibidores da Protease de HIV/farmacocinética , Modelos Moleculares , Mutação , Ligação Proteica , Pirróis/química , Pirróis/farmacocinética , Pirróis/farmacologiaRESUMO
We report the total synthesis of the cytotoxic agent (-)-anthoplalone and the determination of its absolute stereochemistry. The cyclopropane moiety was prepared using a nonracemic bicyclic chloroallyl phosphonamide anion addition to tert-butyl 3,3-dimethyl acrylate. Several pathways were studied to secure the E-trisubstituted olefin of the left part of the molecule.
RESUMO
MISER chromatography was evaluated to increase data processing speed for a rapid, miniaturized in vitro formulation screen. This approach permitted quick data interpretation by eliminating time-consuming steps such as integration, quantitation and report generation. Some flexibility in analytical methodology was lost due to limited instrument platforms capable of injecting multiple samples and acquiring all data in a single chromatogram. In our instrumental setup, an isocratic run was used to perform MISER chromatography, producing results comparable to our generic gradient methods while reducing processing times. This novel data format was easily interpreted and provides equivalent information to a formulation scientist as compared to traditional tabulated reports.
Assuntos
Química Farmacêutica/métodos , Cromatografia/métodosRESUMO
Our docking program, Fitted, implemented in our computational platform, Forecaster, has been modified to carry out automated virtual screening of covalent inhibitors. With this modified version of the program, virtual screening and further docking-based optimization of a selected hit led to the identification of potential covalent reversible inhibitors of prolyl oligopeptidase activity. After visual inspection, a virtual hit molecule together with four analogues were selected for synthesis and made in one-five chemical steps. Biological evaluations on recombinant POP and FAPα enzymes, cell extracts, and living cells demonstrated high potency and selectivity for POP over FAPα and DPPIV. Three compounds even exhibited high nanomolar inhibitory activities in intact living human cells and acceptable metabolic stability. This small set of molecules also demonstrated that covalent binding and/or geometrical constraints to the ligand/protein complex may lead to an increase in bioactivity.
Assuntos
Inibidores de Proteases/farmacologia , Serina Endopeptidases/metabolismo , Interface Usuário-Computador , Animais , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Humanos , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Prolil Oligopeptidases , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Conformação Proteica , Ratos , Serina Endopeptidases/química , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
Modulation of PPAR activities represents an attractive approach for the treatment of diabetes with associated cardiovascular complications. The indanylacetic acid structural motif has proven useful in the generation of potent and tunable PPAR ligands. Modification of the substituents on the linker and the heterocycle tail group allowed for the modulation of the selectivity at the different receptor subtypes. Compound 33 was evaluated in vivo, where it displayed the desired reduction of glucose levels and increase in HDL levels in various animal models.
Assuntos
Acetatos/síntese química , Acetatos/farmacologia , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacologia , Indanos/síntese química , Indanos/farmacologia , PPAR alfa/agonistas , PPAR delta/agonistas , PPAR gama/agonistas , Animais , Área Sob a Curva , Glicemia/metabolismo , Células Cultivadas , Colesterol/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/genética , Relação Dose-Resposta a Droga , Humanos , Hidrólise , Hipoglicemiantes/farmacocinética , Indicadores e Reagentes , Lipoproteínas HDL/sangue , Camundongos , Ratos , Ratos Zucker , Rosiglitazona , Relação Estrutura-Atividade , Tiazolidinedionas/uso terapêuticoRESUMO
Modulation of cAMP levels has been linked to insulin secretion in preclinical animal models and in humans. The high expression of PDE-10A in pancreatic islets suggested that inhibition of this enzyme may provide the necessary modulation to elicit increased insulin secretion. Using an HTS approach, we have identified quinoline-based PDE-10A inhibitors as insulin secretagogues in vitro. Optimized compounds were evaluated in vivo where improvements in glucose tolerance and increases in insulin secretion were measured.
Assuntos
Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Quinolinas/farmacologia , Desenho de Fármacos , Humanos , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Estrutura Molecular , Inibidores de Fosfodiesterase/síntese química , Diester Fosfórico Hidrolases/efeitos dos fármacos , Quinolinas/síntese química , Quinolinas/química , Relação Estrutura-AtividadeRESUMO
A series of indane acetic acid derivatives were prepared which show a spectrum of activity as insulin sensitizers and PPAR-alpha and PPAR-delta ligands. In vivo data are presented for insulin sensitizers with selectivity for PPAR-delta over PPAR-alpha.
Assuntos
Resistência à Insulina , PPAR delta/agonistas , Transferência Ressonante de Energia de Fluorescência , Relação Estrutura-AtividadeRESUMO
A series of monopyrrolinone-based HIV-1 protease inhibitors possessing rationally designed P2' side chains have been synthesized and evaluated for activity against wild-type HIV-1 protease. The most potent inhibitor displays subnanomolar potency in vitro for the wild-type HIV-1 protease. Additionally, the monopyrrolinone inhibitors retain potency in cellular assays against clinically significant mutant forms of the virus. X-ray structures of these inhibitors bound in the wild-type enzyme reveal important insights into the observed biological activity.