RESUMO
Computer aided drug-design methods proved to be powerful tools for the identification of new therapeutic agents. We employed a structure-based workflow to identify new inhibitors targeting mTOR kinase at rapamycin binding site. By combining molecular dynamics (MD) simulation and pharmacophore modelling, a simplified structure-based pharmacophore hypothesis was built starting from the FKBP12-rapamycin-FRB ternary complex retrieved from RCSB Protein Data Bank (PDB code 1FAP). Then, the obtained model was used as filter to screen the ZINC biogenic compounds library, containing molecules derived from natural sources or natural-inspired compounds. The resulting hits were clustered according to their similarity; moreover, compounds showing the highest pharmacophore fit-score were chosen from each cluster. The selected molecules were subjected to docking studies to clarify their putative binding mode. The binding free energy of the obtained complexes was calculated by MM/GBSA method and the hits characterized by the lowest ΔGbind values were identified as potential mTOR inhibitors. Furthermore, the stability of the resulting complexes was studied by means of MD simulation which revealed that the selected compounds were able to form a stable ternary complex with FKBP12 and FRB domain, thus underlining their potential ability to inhibit mTOR with a rapamycin-like mechanism.
Assuntos
Simulação por Computador , Inibidores de Proteínas Quinases/farmacologia , Sirolimo/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Sítios de Ligação , Avaliação Pré-Clínica de Medicamentos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Domínios Proteicos , Proteína 1A de Ligação a Tacrolimo/química , Proteína 1A de Ligação a Tacrolimo/metabolismo , Interface Usuário-ComputadorRESUMO
Melanogenesis controls the formation of melanin pigment whose overproduction is related to various hyperpigmentary disorders in humans. Tyrosinase is a type-3 copper enzyme involved in the rate limiting step of melanin synthesis, therefore its inhibition could represent an efficient way for the development of depigmenting agents. In this work, a combination of pharmacophore and docking-based studies has been employed to screen two in-house 3D compound databases containing about 2,000 molecules from natural and synthetic sources. As result we selected two "hit compounds" which proved to inhibit tyrosinase activity showing IC50 values in the micromolar range.
Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/antagonistas & inibidores , Piperazina/farmacologia , Piperidinas/farmacologia , Agaricales/enzimologia , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Estrutura Molecular , Monofenol Mono-Oxigenase/metabolismo , Piperazina/química , Piperidinas/químicaRESUMO
A previous report indicated that the flavonoid-rich extract of bergamot juice (BJe) exerts an anti-inflammatory effect through the activation of SIRT1 in leukemic monocytes THP-1 exposed to lipopolysaccharide (LPS). In this study, we deeply investigate the mode of action of BJe, along with its major flavonoids on SIRT1 through cell-free, in silico, and in vitro experimental models. In the cell-free assay, all the tested compounds as well as the whole BJe inhibited the deacetylase activity of SIRT1. This finding was reinforced by the results of the in silico study. In THP-1 cells exposed to LPS, a reduction of SIRT1 activity was observed, effect that was reverted by the pre-incubation with either BJe or its major flavonoids. This effect was also observed at gene level. Employing an activator and an inhibitor of AMP-activated protein kinase (AMPK; AICAR and dorsomorphin, respectively), we discovered its involvement in the activation of SIRT1 elicited by BJe or its major flavonoids in whole cell. Our study indicates the dual role of BJe and its components, depending on the employed experimental model as well as reveals their mode of action on the AMPK/SIRT1 axis, suggesting their role as promising candidates in pathologies in which this axis is implied.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Citrus , Flavonoides/farmacologia , Extratos Vegetais/farmacologia , Sirtuína 1/metabolismo , Simulação por Computador , Humanos , Lipopolissacarídeos/farmacologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Células THP-1RESUMO
Chemotherapy is currently the only effective approach to treat all forms of leishmaniasis. However, its effectiveness is severely limited due to high toxicity, long treatment length, drug resistance, or inadequate mode of administration. As a consequence, there is a need to identify new molecular scaffolds and targets as potential therapeutics for the treatment of this disease. We report a small series of 1,2-substituted-1H-benzo[d]imidazole derivatives (9a-d) showing affinity in the submicromolar range (Ki = 0.15-0.69 µM) toward Leishmania mexicanaCPB2.8ΔCTE, one of the more promising targets for antileishmanial drug design. The compounds confirmed activity in vitro against intracellular amastigotes of Leishmania infantum with the best result being obtained with derivative 9d (IC50 = 6.8 µM), although with some degree of cytotoxicity (CC50 = 8.0 µM on PMM and CC50 = 32.0 µM on MCR-5). In silico molecular docking studies and ADME-Tox properties prediction were performed to validate the hypothesis of the interaction with the intended target and to assess the drug-likeness of these derivatives.
Assuntos
Benzimidazóis/química , Cisteína Proteases/metabolismo , Inibidores de Cisteína Proteinase/química , Leishmania mexicana/enzimologia , Proteínas de Protozoários/antagonistas & inibidores , Antiprotozoários/síntese química , Antiprotozoários/metabolismo , Antiprotozoários/uso terapêutico , Antiprotozoários/toxicidade , Benzimidazóis/metabolismo , Benzimidazóis/uso terapêutico , Benzimidazóis/toxicidade , Sítios de Ligação , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cisteína Proteases/química , Inibidores de Cisteína Proteinase/metabolismo , Inibidores de Cisteína Proteinase/uso terapêutico , Inibidores de Cisteína Proteinase/toxicidade , Avaliação Pré-Clínica de Medicamentos , Ensaios Enzimáticos , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Leishmaniose/tratamento farmacológico , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Proteínas de Protozoários/metabolismoRESUMO
The disruption of crucial interactions between HIV-1 Integrase and cellular cofactor LEDGF/p75 represents an emerging approach for the design and development of new antiretroviral agents. In this study we report the successful application of a structure-based virtual screening strategy for the discovery of natural hit structures able to inhibit Integrase-LEDGF/p75 interaction. The application of sequential filters (drug-likeness, 3D-pharmacophore mapping, docking, molecular dynamics simulations) yielded a hit list of compounds, out of which 9 were tested in the in vitro AlphaScreen assays and 8 exhibited a detectable inhibition of the interaction between the two proteins. The best inhibitors belong to different chemical classes and could be represent a good starting point for further optimization and structure-activity relationship studies.
Assuntos
Inibidores de Integrase/química , Inibidores de Integrase/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Bioensaio , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Inibidores de Integrase de HIV/química , Inibidores de Integrase de HIV/farmacologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/agonistas , Peptídeos e Proteínas de Sinalização Intercelular/química , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura MolecularRESUMO
We have identified 1H-benzylindole analogues as a novel series of human immunodeficiency virus (HIV) integrase inhibitors with antiretroviral activities against different strains of HIV type 1 (HIV-1), HIV-2, and simian immunodeficiency virus strain MAC(251) [SIV(MAC(251))]. Molecular modeling and structure-activity relationship-based optimization resulted in the identification of CHI/1043 as the most potent congener. CHI/1043 inhibited the replication of HIV-1(III(B)) in MT-4 cells at a 50% effective concentration (EC(50)) of 0.60 microM, 70-fold below its cytotoxic concentration. Equal activities against HIV-1(NL4.3), HIV-2(ROD), HIV-2(EHO), and SIV(MAC(251)) were observed. CHI/1043 was equally active against virus strains resistant against inhibitors of reverse transcriptase or protease. Replication of both X4 and R5 strains in peripheral blood mononuclear cells was sensitive to the inhibitory effect of CHI/1043 (EC(50), 0.30 to 0.38 microM). CHI/1043 inhibited integrase strand transfer activity in oligonucleotide-based enzymatic assays at low micromolar concentrations. Time-of-addition experiments confirmed CHI/1043 to interfere with the viral replication cycle at the time of retroviral integration. Quantitative Alu PCR corroborated that the anti-HIV activity is based upon the inhibition of proviral DNA integration. An HIV-1 strain selected for 70 passages in the presence of CHI/1043 was evaluated genotypically and phenotypically. The mutations T66I and Q146K were present in integrase. Cross-resistance to other integrase strand transfer inhibitors, such as L-708,906, the naphthyridine analogue L-870,810, and the clinical drugs GS/9137 and MK-0518, was observed. In adsorption, distribution, metabolism, excretion, and toxicity studies, antiviral activity was strongly reduced by protein binding, and metabolization in human liver microsomes was observed. Transport studies with Caco cells suggest a low oral bioavailability.
Assuntos
Inibidores de Integrase de HIV/farmacologia , HIV/efeitos dos fármacos , Indóis/farmacologia , Integrases/metabolismo , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Células CACO-2 , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Ensaio de Imunoadsorção Enzimática , HIV/enzimologia , HIV/genética , Inibidores de Integrase de HIV/síntese química , Inibidores de Integrase de HIV/química , Humanos , Indóis/síntese química , Indóis/química , Integrases/genética , Estrutura Molecular , Reação em Cadeia da Polimerase , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
In our studies on the development of new anticonvulsants, we planned the synthesis of N-substituted 1,2,3,4-tetrahydroisoquinolines to explore the structure-activity relationships. All derivatives were evaluated against audiogenic seizures in DBA/2 mice, and the 1-(4'-bromophenyl)-6,7-dimethoxy-2-(piperidin-1-ylacetyl) derivative (26) showed the highest activity with a potency comparable to that of talampanel, the only noncompetitive alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) antagonist in clinical trials as an anticonvulsant agent. Electrophysiological experiments indicated that 26 acts as noncompetitive AMPA receptor modulator.
Assuntos
Anticonvulsivantes/síntese química , Isoquinolinas/síntese química , Piperidinas/síntese química , Tetra-Hidroisoquinolinas/síntese química , Estimulação Acústica , Animais , Anticonvulsivantes/química , Anticonvulsivantes/farmacologia , Técnicas In Vitro , Isoquinolinas/química , Isoquinolinas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos DBA , Condutos Olfatórios/efeitos dos fármacos , Condutos Olfatórios/fisiologia , Piperidinas/química , Piperidinas/farmacologia , Ratos , Ratos Wistar , Receptores de AMPA/efeitos dos fármacos , Receptores de AMPA/fisiologia , Convulsões/etiologia , Convulsões/prevenção & controle , Relação Estrutura-Atividade , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/farmacologiaRESUMO
A 3D pharmacophore model predicting anticonvulsant activity was obtained for a series of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives recently disclosed as a new class of noncompetitive AMPA receptor antagonists. The training set included 17 compounds with varying potency against audiogenic seizures in DBA/2 mice. The best statistical hypothesis, generated with the HypoGen module of Catalyst 4.9, consisted of five features: two hydrogen bond acceptors, two hydrophobic features, and one hydrophobic aromatic region, providing a model with a correlation coefficient of 0.919. The obtained model was an efficient tool in the design of some new anticonvulsant agents containing the tetrahydroisoquinoline scaffold. Moreover, in order to explain the different degree of efficacy of the newly designed N-substituted derivatives, excluded volumes were also considered.
Assuntos
Anticonvulsivantes/química , Modelos Moleculares , Tetra-Hidroisoquinolinas/química , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Benzodiazepinas/química , Benzodiazepinas/farmacologia , Benzodiazepinas/uso terapêutico , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Epilepsia Reflexa/induzido quimicamente , Epilepsia Reflexa/prevenção & controle , Feminino , Isoquinolinas/química , Isoquinolinas/farmacologia , Isoquinolinas/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos DBA , Modelos Animais , Conformação Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Tetra-Hidroisoquinolinas/farmacologia , Tetra-Hidroisoquinolinas/uso terapêuticoRESUMO
We describe the use of pharmacophore modeling as an efficient tool in the discovery of novel HIV-1 integrase (IN) inhibitors. A three-dimensional hypothetical model for the binding of diketo acid analogues to the enzyme was built by means of the Catalyst program. Using these models as a query for virtual screening, we found several compounds that contain the specified 3D patterns of chemical functions. Biological testing shows that our strategy was successful in searching for new structural leads as HIV-1 IN inhibitors.
Assuntos
Avaliação Pré-Clínica de Medicamentos/estatística & dados numéricos , Inibidores de Integrase de HIV/química , Inibidores de Integrase de HIV/farmacologia , Simulação por Computador , DNA Viral/efeitos dos fármacos , DNA Viral/genética , Bases de Dados Factuais , Desenho de Fármacos , HIV-1/efeitos dos fármacos , HIV-1/enzimologia , HIV-1/genética , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Interface Usuário-ComputadorRESUMO
VacA is a major virulence factor of the widespread stomach-dwelling bacterium Helicobacter pylori. It causes cell vacuolation and tissue damage by forming anion-selective, urea-permeable channels in plasma and endosomal membranes. We report that several flavone derivatives and other polyphenols present in vegetables and plants inhibit ion and urea conduction and cell vacuolation by VacA. Red wine and green tea, which contain many of the compounds in question, also potently inhibit the toxin. These observations suggest that polyphenols or polyphenol derivatives may be useful in the prevention or cure of H. pylori-associated gastric diseases.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Toxinas Bacterianas/antagonistas & inibidores , Flavonoides , Helicobacter pylori/efeitos dos fármacos , Fenóis/farmacologia , Polímeros/farmacologia , Antibacterianos/química , Transporte Biológico/efeitos dos fármacos , Condutividade Elétrica , Células HeLa , Helicobacter pylori/patogenicidade , Humanos , Fenóis/química , Plantas/química , Polímeros/química , Polifenóis , Estômago/microbiologia , Chá/química , Ureia/metabolismo , VinhoRESUMO
N-Acetyl-1-aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives were designed and synthesized as potential noncompetitive AMPA receptor antagonists on the basis of molecular modeling studies. Sound-induced seizure testing showed that this class of compounds possessed anticonvulsant properties. In particular, 10c was more potent than talampanel (2), a noncompetitive AMPA receptor antagonist currently being investigated in phase III trials as an antiepileptic agent. Furthermore, electrophysiological studies indicated that 10c was a highly effective noncompetitive-type modulator of the AMPA receptor.