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1.
Bioinformatics ; 38(2): 469-475, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34979024

RESUMO

MOTIVATION: The aim of quantitative structure-activity prediction (QSAR) studies is to identify novel drug-like molecules that can be suggested as lead compounds by means of two approaches, which are discussed in this article. First, to identify appropriate molecular descriptors by focusing on one feature-selection algorithms; and second to predict the biological activities of designed compounds. Recent studies have shown increased interest in the prediction of a huge number of molecules, known as Big Data, using deep learning models. However, despite all these efforts to solve critical challenges in QSAR models, such as over-fitting, massive processing procedures, is major shortcomings of deep learning models. Hence, finding the most effective molecular descriptors in the shortest possible time is an ongoing task. One of the successful methods to speed up the extraction of the best features from big datasets is the use of least absolute shrinkage and selection operator (LASSO). This algorithm is a regression model that selects a subset of molecular descriptors with the aim of enhancing prediction accuracy and interpretability because of removing inappropriate and irrelevant features. RESULTS: To implement and test our proposed model, a random forest was built to predict the molecular activities of Kaggle competition compounds. Finally, the prediction results and computation time of the suggested model were compared with the other well-known algorithms, i.e. Boruta-random forest, deep random forest and deep belief network model. The results revealed that improving output correlation through LASSO-random forest leads to appreciably reduced implementation time and model complexity, while maintaining accuracy of the predictions. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Big Data , Relação Quantitativa Estrutura-Atividade , Algoritmos , Análise de Dados
2.
Mol Divers ; 2023 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-37120484

RESUMO

Hypoxia-inducible factors (HIFs) are the main regulatory factors implicated in the adaptation of cancer cells to hypoxic stress, which has provoked much interest as an attractive target for the design of promising chemotherapeutic agents. Since indirect HIF inhibitors (HIFIs) lead to the occurrence of various side effects, the need of the hour is to develop direct HIFIs, physically interacting with important functional domains within the HIF protein structure. Accordingly, in the present study, it was attempted to develop an exhaustive structure-based virtual screening (VS) process coupled with molecular docking, molecular dynamic (MD) simulation, and MM-GBSA calculations for the identification of novel direct inhibitors against the HIF-2α subunit. For this purpose, a focused library of over 200,000 compounds from the NCI database was used for VS against the PAS-B domain of the target protein, HIF-2α. This domain was suggested to be a possible ligand-binding site, which is characterized by a large internal hydrophobic cavity, unique to the HIF-2α subunit. The top-ranked compounds, NSC106416, NSC217021, NSC217026, NSC215639, and NSC277811 with the best docking scores were taken up for the subsequent in silico ADME properties and PAINS filtration. The selected drug-like hits were employed for carrying out MD simulation which was followed by MM-GBSA calculations to retrieve the candidates showing the highest in silico binding affinity towards the PAS-B domain of HIF-2α. The analysis of results indicated that all molecules, except the NSC277811, fulfilled necessary drug-likeness properties. Four selected drug-like candidates, NSC106416, NSC217021, NSC217026, and NSC215639 were found to expose the stability profiles within the cavity located inside the PAS-B domain of HIF-2α over simulation time. Finally, the results of the MM-GBSA rescoring method were indicative of the highest binding affinity of NSC217026 for the binding site of the HIF-2α PAS-B domain among selected final hits. Consequently, the hit NSC217026 could serve as a promising scaffold for further optimization toward the design of direct HIF-2α inhibitors for cancer therapy.

3.
Chem Biodivers ; 20(7): e202300325, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37347200

RESUMO

Researchers have focused on inhibiting acetylcholinesterase for Alzheimer's disease treatment. In this study, some novel AChE inhibitors were synthesized using hydroxypyridin-4-one plus benzylpiperidine scaffolds which were evaluated using Ellman's method. Accordingly, ((1-(4-methoxyphenethyl)piperidin-4-yl)amino)methyl)-5-hydroxy-1-methylpyridin-4(1H)-one (VIId ) showed weaker but promising AChE inhibition compared to donepezil (IC50 =143.090 nM). The average RMSD values of VIId was found to be 2.25 indicated less structural changes in the active site residues. The phenyl group of the phenyl-ethyl-N-piperidine moiety of VIId formed hydrophobic interactions with Trp285 and Tyr340. There was a π-cation interaction between nitrogen atom of piperidine ring and Phe294. Another π-cation interaction was found between type 2 amine of linker and Trp85. Piperidine ring interacted with Tyr336, Tyr123, and Phe337 through hydrophobic interactions. Indeed, the VIId was predicted to be absorbed across the gastrointestinal tract, though it may be pumped out by P-gp. Indeed, VIId can permeate through the blood brain barrier. MD simulation studies revealed that benzyloxy moiety plays a role similar to benzylpiperidine moiety of donepezil in binding to the active site residues. Also, carbonyl group functioned similar to indanone ketone group. Overall; further research on VIId may lead to introduction of a novel class of AChE inhibitors.


Assuntos
Doença de Alzheimer , Inibidores da Colinesterase , Humanos , Inibidores da Colinesterase/química , Donepezila , Simulação de Acoplamento Molecular , Acetilcolinesterase/metabolismo , Simulação de Dinâmica Molecular , Piperidinas/farmacologia , Piperidinas/química , Doença de Alzheimer/tratamento farmacológico , Piridinas/farmacologia , Relação Estrutura-Atividade
4.
Chem Biodivers ; 20(10): e202301113, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37691012

RESUMO

Some novel inhibitors based on the (benzo[d]thiazol-2-yl)-1-phenylmethanimine derivatives were designed to reduce the aggregation process in Alzheimer's disease. These structures seem to mimic stilbene-like scaffold, while the benzothiazole moiety "locks" the thioflavin T binding site. Other inhibitors were designed based on 2-((benzo[d]thiazol-2-ylimino)methyl)-5-(benzyloxy)-1-methylpyridin-4(H)-one derivatives. Benzo[d]thiazol-2-amine derivatives were prepared by the reaction of aniline derivatives with ammonium thiocyanate in the presence of bromine/acetic acid. Then, the reaction of amines with benzaldehyde derivatives and 5-(benzyloxy)-1-methyl-4-oxo-1,4-dihydropyridine-2-carbaldehyde gave the desired compounds. The plate reader-based fibrillation assay was done to evaluate the inhibition of Aß aggregation. Also, molecular dynamic simulation was carried out to clarify the interaction manner of the designed compounds with Aß formation. The biological evaluation proved 5a and 7e as the best inhibitor of the Aß aggregation. compound 5a in the concentration of 50 µM inhibited Aß fibril formation better than 7e. MD simulation elucidated that the Aß aggregation inhibitors in different concentrations represented different binding conformations throughout the entire or in one area of Aß. MD showed the ligands in lower concentrations accumulate in an area of Aß aggregations and separate one fibril from the aggregated Aß. On the contrary, in higher concentrations, the ligands tend to be located through the entire Aß.

5.
Bioorg Med Chem Lett ; 70: 128784, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35569690

RESUMO

Keeping in view the pharmacological properties of indolinones as promising scaffold as kinase inhibitors, herein, a novel series of 3-hydrazonoindolin-2-one derivatives bearing 3-hydroxy-4-pyridinone moiety were synthesized, studied by molecular docking, and fully characterized by spectroscopic techniques. All the prepared compounds were evaluated for their cytotoxicity attributes against a panel of tumor cell lines, including non-small cell lung cancer (A549), breast carcinoma (MCF-7), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). They displayed moderate to promising antiproliferative effects toward A549 and MCF-7 cells but remarkable results against AML and CML. Especially, compound 10k was found to be more potent against AML (EC50 = 0.69 µM) compare to the other halogen-substituted derivatives. FMS-like tyrosine kinase 3 (FLT3) is known to be expressed in AML cancer cells. The molecular docking studies demonstrated that our prepared compounds were potentially bound to AML active site through essential H-bond and other vital interactions with critical binding residues.


Assuntos
Antineoplásicos , Indóis , Inibidores de Proteínas Quinases , Células A549 , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Indóis/química , Indóis/farmacologia , Células MCF-7 , Simulação de Acoplamento Molecular , Oxindóis/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Piridonas/química , Piridonas/farmacologia , Relação Estrutura-Atividade , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/metabolismo
6.
Chem Biodivers ; 19(3): e202100703, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34997823

RESUMO

The current study on the antioxidant activity of kojic acid and 3-hydroxypyridine-4-one derivatives was performed by implementation of density functional theory calculations with the B3LYP hybrid functional and the 6-311++G** basis set in Polarizable Continuum Model of solvation. Compounds under evaluation were previously synthesized by our research group. The DPPH scavenging effect and the IC50 values in mM concentrations were evaluated. Subsequently, various electronic and energetic descriptors such as HOMO and LUMO energy gaps, bonding dissociation enthalpy of an OH bond, ionization potential, electron affinity, hardness, softness, NBOs and spin density of radical and neutral species were used to study antioxidant properties of investigated compounds. The computations detected two compounds, HP3 and HP4, with significant antioxidant activity. Energetic descriptors indicated that the SPLET mechanism is preferred over the other antioxidation mechanism and computational results were in accordance with the experimental results.


Assuntos
Antioxidantes , Piridonas , Antioxidantes/química , Antioxidantes/farmacologia , Fenômenos Químicos , Termodinâmica
7.
Mol Pharm ; 18(1): 275-284, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33300343

RESUMO

In recent years, the exploitation of magnetic nanoparticles in smart polymeric matrices have received increased attention in several fields as site-specific drug delivery systems. Here, ultrasonic-assisted emulsion copolymerization of N-isopropylacrylamide (NIPAM) and 2-(N,N-diethylaminoethyl) methacrylate (DEAEMA) in the presence of Fe3O4 nanoparticles was employed to prepare pH- and temperature-responsive magnetite nanocomposite particles (MNCPs). The obtained MNCPs were fully characterized by TEM, DSC, FT-IR, VSM, and XRD techniques. They had an average particle size of 70 nm with a lower critical solution temperature of 42 °C and superparamagnetic properties. In addition, MNCPs were loaded with methotrexate (MTX) as an anticancer drug, and their in vitro drug release was studied in different pH values and temperatures and in the presence of an alternating magnetic field. Noteworthy that the highest rate of MTX release was observed at pH 5.5 and 42 °C. Cell viability of the treated MCF-7 human breast cancer cell line with free MTX, MNCPs, and MTX-loaded MNCPs or in combination with magnetic hyperthermia (MHT) and water-based hyperthermia was comparatively studied. The obtained results showed about 17% higher antiproliferative activity for the MTX-loaded MNCPs accompanied by MHT relative to that of free MTX.


Assuntos
Hidrogéis/química , Hipertermia/tratamento farmacológico , Nanopartículas de Magnetita/química , Metotrexato/química , Metotrexato/farmacologia , Nanogéis/química , Neoplasias/tratamento farmacológico , Acrilamidas/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Metacrilatos/química , Nanocompostos/química , Tamanho da Partícula , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
8.
Chem Biodivers ; 16(2): e1800339, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30284762

RESUMO

Eight derivatives of tetrahydropyrimidine scaffold were designed and prepared as hybrid compounds possessing the structural features of both monastrol as an anticancer drug and nifedipine as a fascin blocking agent. All of the compounds were evaluated for their cytotoxic potency and the ability to inhibit 4T1 breast cancer cells migration. Then, they were investigated in silico for their ability to inhibit the fascin protein using molecular docking simulation. The most potent compound was 4d and the weakest one was 4a according to the in vitro cytotoxicity assay. The corresponding IC50 values were 193.70 and 248.75 µm, respectively. The least cytotoxic compound (4a) was one of the strongest ones in binding to the fascin binding site according to the molecular docking results. 4a and 4e inhibited the 4T1 cells migration better than other compounds. They were more potent than nifedipine in inhibiting the migration process. In silico studies proved 4h to be the most potent fascin inhibitor in terms of ΔGbind although it was not inhibiting migration. The controversy between the in vitro and in silico results may cancel the theory of the involvement of the fascin inhibition in the migration inhibition. However, the considerable antimigratory effects of some of the synthesized compounds encourage performing further in vivo experiments to introduce novel tumor metastasis inhibitors.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Transporte/antagonistas & inibidores , Movimento Celular/efeitos dos fármacos , Desenho de Fármacos , Proteínas dos Microfilamentos/antagonistas & inibidores , Pirimidinas/farmacologia , Antineoplásicos/síntese química , Neoplasias da Mama/patologia , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Humanos , Concentração Inibidora 50 , Proteínas dos Microfilamentos/metabolismo , Simulação de Acoplamento Molecular , Nifedipino , Pirimidinas/síntese química , Pirimidinas/metabolismo
9.
Chem Biodivers ; 16(4): e1800470, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30845369

RESUMO

In this work, two novel series of indole-thiosemicarbazone derivatives were designed, synthesized, and evaluated for their cytotoxic activity against MCF-7, A-549, and Hep-G2 cell lines in comparison to etoposide and colchicine as the reference drugs. Generally, the synthesized compounds showed better cytotoxicity towards A-549 and Hep-G2 than MCF-7. Among them, (2E)-2-{[2-(4-chlorophenyl)-1H-indol-3-yl]methylidene}-N-(4-methoxyphenyl)hydrazinecarbothioamide (8l) was found to be the most potent compound against A-549 and Hep-G2, at least three times more potent than etoposide. The morphological analysis by the acridine orange/ethidium bromide double staining test and flow cytometry analysis indicated that compound 8l induced apoptosis in A-549 cells. Moreover, molecular docking methodology was exploited to elucidate the details of molecular interactions of the studied compounds with putative targets.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Indóis/farmacologia , Tiossemicarbazonas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indóis/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Tiossemicarbazonas/química
10.
Chem Biodivers ; 15(10): e1800159, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30027572

RESUMO

The HIV-1 life cycle consists of different events, such as cell entry and fusion, virus replication, assembly and release of the newly formed virions. The more logical way to inhibit HIV transmission among individuals is to inhibit its entry into the immune host cells rather than targeting the intracellular viral enzymes. Both viral and host cell surface receptors and co-receptors are regarded as potential targets in anti-HIV-1 drug design process. Because of the importance of this topic it was decided to summarize recent reports on small-molecule HIV-1 entry inhibitors that have not been considered in the latest released reviews. All the computational studies reported in the literature regarding HIV-1 entry inhibitors since 2014 was also considered in this review.


Assuntos
Desenho de Fármacos , Inibidores da Fusão de HIV/química , Inibidores da Fusão de HIV/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Proteína gp120 do Envelope de HIV/antagonistas & inibidores , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp41 do Envelope de HIV/antagonistas & inibidores , Proteína gp41 do Envelope de HIV/metabolismo , Inibidores da Fusão de HIV/uso terapêutico , Infecções por HIV/metabolismo , HIV-1/fisiologia , Humanos , Receptores CCR5/metabolismo , Receptores CXCR4/antagonistas & inibidores , Receptores CXCR4/metabolismo , Bibliotecas de Moléculas Pequenas/uso terapêutico , Internalização do Vírus/efeitos dos fármacos
11.
Chem Biodivers ; 15(10): e1800228, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29999602

RESUMO

Two novel bis-arylimidamide derivatives with terminal catechol moieties (9a and 10a) and two parent compounds with terminal phenyl groups (DB613 and DB884) were synthesized as dihydrobromide salts (9b and 10b). The designed compounds were hybrid molecules consisting of a catechol functionality embedded in an arylimidamide moiety. All compounds were examined for in vitro antiparasitic activity upon promastigotes of Leishmania major and L. infantum as well as axenic amastigotes of L. major. It was shown that conversion of terminal phenyl groups into catechol moieties resulted in more than 10-fold improvement in potency, coupled with lower cytotoxicity against fibroblast cells, compared to the corresponding parent compounds. The furan-containing analog 9a exhibited the highest activity with submicromolar IC50 values, ranging from 0.29 to 0.36 µm, which is comparable in efficacy to the reference drug amphotericin B (IC50 0.28 - 0.33 µm). The results justify further study of this class of compounds. It seems that the combination of catechol chelating groups with potent antiparasitic agents could improve the efficacy by presenting novel hybrid compounds.


Assuntos
Catecóis/química , Catecóis/farmacologia , Desenho de Fármacos , Leishmania/efeitos dos fármacos , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Linhagem Celular , Humanos , Concentração Inibidora 50 , Leishmaniose/tratamento farmacológico
12.
Chem Biodivers ; 15(4): e1700502, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29411517

RESUMO

A series of tetrahydropyrimidine derivatives (2a - 2l) were designed, synthesized, and screened for anti-HIV-1 properties based on the structures of HIV-1 gp41 binding site inhibitors, NB-2 and NB-64. A computational study was performed to predict the pharmacodynamics, pharmacokinetics, and drug-likeness features of the studied molecules. Docking studies revealed that the carboxylic acid group in the molecules forms salt bridges with either Lys574 or Arg579. Physiochemical properties (e.g., molecular weight, number of hydrogen bond donors, number of hydrogen bond acceptors, and number of rotatable bonds) of the synthesized compounds confirmed and exhibited that these compounds were within the range set by Lipinski's rule of five. Compounds 2e and 2k with 4-chlorophenyl substituent and 4-methylphenyl group at C(4) position of the tetrahydropyrimidine ring was the most potent one among the tested compounds. This suggests that these compounds may serve as leads for development of novel small-molecule HIV-1 inhibitors.


Assuntos
Fármacos Anti-HIV/farmacologia , Ácidos Carboxílicos/farmacologia , Desenho de Fármacos , HIV-1/efeitos dos fármacos , Pirimidinas/farmacologia , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-Atividade
13.
J Comput Chem ; 38(4): 195-203, 2017 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-27862046

RESUMO

Thousands of molecules and descriptors are available for a medicinal chemist thanks to the technological advancements in different branches of chemistry. This fact as well as the correlation between them has raised new problems in quantitative structure activity relationship studies. Proper parameter initialization in statistical modeling has merged as another challenge in recent years. Random selection of parameters leads to poor performance of deep neural network (DNN). In this research, deep belief network (DBN) was applied to initialize DNNs. DBN is composed of some stacks of restricted Boltzmann machine, an energy-based method that requires computing log likelihood gradient for all samples. Three different sampling approaches were suggested to solve this gradient. In this respect, the impact of DBN was applied based on the different sampling approaches mentioned above to initialize the DNN architecture in predicting biological activity of all fifteen Kaggle targets that contain more than 70k molecules. The same as other fields of processing research, the outputs of these models demonstrated significant superiority to that of DNN with random parameters. © 2016 Wiley Periodicals, Inc.


Assuntos
Desenho de Fármacos , Redes Neurais de Computação , Relação Quantitativa Estrutura-Atividade , Algoritmos , Simulação por Computador , Modelos Teóricos
14.
Chem Biodivers ; 14(12)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28834275

RESUMO

The structural similarities between N1 substituted 1,4-dihydropyridines and the known gp41 inhibitors, NB-2 and NB-64, were considered in the current research for the design of some novel anti-HIV-1 agents. A series of novel 4-[4-arylpyridin-1(4H)-yl]benzoic acid derivatives were synthesized and after a comprehensive structural elucidation were screened for in vitro anti-HIV-1 activity. Most of the tested compounds displayed moderate to good inhibitory activity against HIV-1 growth and were evaluated for in vitro cytotoxic activity using XTT assay at the concentration of 100 µm. Among the tested compounds, 1c, 1d and 1e showed potent anti-HIV-1 activity against P24 expression at 100 µm with inhibition percentage of 84.00%, 76.42% and 80.50%, respectively. All the studied compounds possessed no significant cytotoxicity on MT-2 cell line. The binding modes of these compounds to gp41 binding site were determined through molecular docking study. Docking studies proved 1a as the most potent compound and binding maps exhibited that the activities might be attributed to the electrostatic and hydrophobic interactions and additional H-bonds with the gp41 binding site. The Lipinski's 'rule of five' and drug-likeness criteria were also calculated for the studied compounds. All derivatives obeyed the Lipinski's 'rule of five' and had drug-like features. The findings of this study suggest that novel 4-[4-arylpyridin-1(4H)-yl]benzoic acid might be a promising scaffold for the discovery and development of novel anti-HIV-1 agents.


Assuntos
Fármacos Anti-HIV/síntese química , Ácido Benzoico/química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Ácido Benzoico/farmacologia , Sítios de Ligação , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Proteína do Núcleo p24 do HIV/genética , Proteína do Núcleo p24 do HIV/metabolismo , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/metabolismo , HIV-1/efeitos dos fármacos , HIV-1/metabolismo , Humanos , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Relação Estrutura-Atividade
15.
Pharm Res ; 32(12): 3899-915, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26264510

RESUMO

PURPOSE: Chitosan-based polymeric micelles (CBPMs) are considered as promising carriers for delivery of anticancer drugs, imaging agents and genes. To optimize the physicochemical, pharmaceutical and biological properties of CBPMs, the molecular mechanisms behind the self-assembly behavior of chitosan (CHI) amphiphilic derivatives are elucidated. METHODS: This study has two stages. In the experimental stage, dexamethasone (DEX) as a hydrophobic group is grafted to CHI in three degrees of substitution in order to obtain CHI derivatives with different degrees of hydrophobicity. These new CHI amphiphilic derivatives (CHI_DEXs) form micelles in water where their critical aggregation concentration (CAC), size and zeta potential are measured. Through comparing the results of these measurements, the change of self-assembly behavior of CHI_DEXs in response to increasing their hydrophobicity is evaluated. Correlating this evaluation with the results of the 13 MD simulations conducted on CHI_DEXs in atomistic molecular dynamics (MD) simulation stage, reveals the molecular mechanisms behind the self-assembly behavior of CHI_DEXs. RESULTS: Our evaluation of the experimental results reveals that increasing hydrophobicity of a CHI amphiphilic derivative would not necessarily cause it to form micelles with lower CAC value, smaller size and lower zeta potential. The MD simulations reveal that there exists a balance between intra- and inter-chain interactions which is responsible for the self-assembly behavior of CHI amphiphilic derivatives. CONCLUSION: An increase in DS of the hydrophobic group triggers a cascade of molecular events that shifts the balance between intra- and inter-chain interactions leading to changes in the CAC, size and zeta potential of the CBPMs.


Assuntos
Quitosana/química , Portadores de Fármacos/química , Micelas , Antineoplásicos Hormonais/administração & dosagem , Dexametasona/administração & dosagem , Interações Hidrofóbicas e Hidrofílicas , Simulação de Dinâmica Molecular , Termodinâmica , Água/química
16.
J Pharm Pharm Sci ; 18(1): 1-52, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25877440

RESUMO

Years after the first report on 1,4-dihydropyridines (1,4-DHPs) and 1,2,3,4-tetrahydropyrimidines (1,2,3,4-THPMs) appeared, they are revisited as plausible therapeutic agents. This is mainly due to the convenient methods that exist for their synthesis and the diverse pharmacologic properties that these scaffolds present. 1,4-Dihydropyridines and 1,2,3,4-tetrahydropyrimidines are usually regarded as analogous in several aspects. They are both prepared in multi-component reactions using very similar starting materials and synthesis protocols. This leads to common structural features between 1,4-DHPs and 1,2,3,4-THPMs, as well several related biological effects. For example, they share many pharmacological features such as analgesic, anti-tumor, antioxidant, anti-inflammatory, antitubercular, antibacterial, cardiovascular and adrenoceptor blocking activities. Numerous reviews have been devoted to the chemistry and cardiovascular effects of these compounds. However, the lack of a comprehensive literature overview on the chemotherapeutic ability of these scaffolds is behind the present attempt to provide a detailed survey of 1,4-DHPs and 1,2,3,4-THPMs and their structural features as chemotherapeutic agents.


Assuntos
Di-Hidropiridinas/farmacologia , Pirimidinas/farmacologia , Animais , Di-Hidropiridinas/química , Humanos , Pirimidinas/química , Relação Estrutura-Atividade
17.
J Pharm Pharm Sci ; 17(4): 461-74, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25579429

RESUMO

PURPOSE: The aim of this study was to investigate the in vitro gene delivery efficiency of poly[N-(2-aminoethyl)ethylene-imine](PAEEI), a polymer with a linear Polyethyleneimine (LPEI) backbone and with aminoethyl side groups that has two protonatable nitrogen atoms per monomer unit instead of one as in LPEI (an established gene delivery polymer). Method. PAEEI (Mn=4.5 kDa, Mw= 10 kDa) was synthesized by ring-opening polymerization of N-(2-(1'-aziridino)ethyl)formamide followed by hydrolysis of the amide groups. The buffering capacity of the resulting polymer was determined by acid-base titration and consequently the percentage of the protonated nitrogen atoms was calculated. Polyplexes were prepared separately in buffers with different ionic strength including Hepes buffered saline (150 mM NaCl) and Hepes buffered glucose (5% glucose) and their zeta-potential, hydrodynamic diameter and colloidal stability were measured. Transfection activity (and toxicity in Hela cells) of the polyplexes were done in HeLa, CHO and HEK293T cells. Cell incubations with polyplexes were done both in the presence and absence (HeLa cells) of serum. Results. PAEEEI showed two times more buffering capacity than LPEI. PAEEI-based Polyplexes had about the same size and zeta-potential as those of LPEI, with a higher colloidal stability in saline buffer in continuous particle size measurement. Their transfection activity was slightly higher than 22-kDa LPEI polyplexes whereas their toxicity profiles were similar in cell lines studied. The PAEEI polyplexes showed gene expression activity both in the presence and absence of serum. Conclusion. Paying attention to the fact that LPEI molecules with smaller sizes than 22 kDa show less transfection efficiency than LPEI 22, the effect of smaller size of PAEEI (10 kDa) on the gene delivery efficiency was compensated by its higher buffering capacity due to carrying more protonatable nitrogen per monomeric unit comparing with LPEI (22 kDa). Having slightly higher transfection efficiency and better colloidal stability than PEI-based systems, PAEEI is an attractive candidate for future in vivo gene delivery studies.


Assuntos
Técnicas de Transferência de Genes , Polietilenoimina/química , Polímeros/química , Transfecção , Animais , Células CHO , Cricetinae , Cricetulus , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Células HeLa , Humanos , Nitrogênio/química , Tamanho da Partícula , Polietilenoimina/toxicidade , Polímeros/toxicidade
18.
Med Chem ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38840401

RESUMO

INTRODUCTION: Drug resistance to existing antimicrobial drugs has become a serious threat to human health, which highlights the need to develop new antimicrobial agents. METHOD: In this study, a new set of 3-hydroxypyridine-4-one derivatives (6a-j) was synthesized, and the antimicrobial effects of these derivatives were evaluated against a variety of microorganisms using the microdilution method. The antimicrobial evaluation indicated that compound 6c, with an electron-donating group -OCH3 at the meta position of the phenyl ring, was the most active compound against S. aureus and E. coli species with an MIC value of 32 µg/mL. Compound 6c was more potent than ampicillin as a reference drug. RESULT: The in vitro antifungal results showed that the studied derivatives had moderate effects (MIC = 128-512 µg/mL) against C. albicans and A. niger species. The molecular modeling studies revealed the possible mechanism and suitable interactions of these derivatives with the target protein. CONCLUSION: The obtained biological results offer valuable insights into the design of more effective antimicrobial agents.

19.
J Enzyme Inhib Med Chem ; 28(1): 16-32, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21999517

RESUMO

A computational procedure was performed on some indenopyrazole derivatives. Two important procedures in computational drug discovery, namely docking for modeling ligand-receptor interactions and quantitative structure activity relationships were employed. MIA-QSAR analysis of the studied derivatives produced a model with high predictability. The developed model was then used to evaluate the bioactivity of 54 proposed indenopyrazole derivatives. In order to confirm the obtained results through this ligand-based method, docking was performed on the selected compounds. An ADME-Tox evaluation was also carried out to search for more suitable compounds. Satisfactory bioactivities and ADME-Tox profiles for two of the compounds, namely 62 and S13, propose that further studies should be performed on such devoted chemical structures.


Assuntos
Antineoplásicos/farmacologia , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Pirazóis/química , Relação Quantitativa Estrutura-Atividade , Antineoplásicos/química , Calibragem , Ligantes , Simulação de Acoplamento Molecular
20.
Int Wound J ; 10(3): 260-4, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22621771

RESUMO

Kojic acid and deferiprone are iron chelators used for skin lightening and iron-overload treatment, respectively. As iron chelation and free radical scavenging are principal factors for wound healing, it was hypothesised that the local application of these compounds might accelerate wound healing in rats. Ointments of 3%, 6% and 9% of deferiprone and kojic acid were prepared and topical treatment was performed on in vivo wound models for 12 days twice in day for test and control groups. Topical treatment with 3%, 6% and 9% showed significant improvement in wound healing after 4 days (P < 0·001). Topical application of 3% and 6% deferiprone enhanced wound healing after 8 days (P < 0·026 and P < 0·001, respectively). Accelerated wound healing was seen using 3% and 6% deferiprone after 12 days (P = 0·003 and P < 0·001, respectively). DPPH scavenging assay was also performed to compare the antioxidant potencies of kojic acid and deferiprone. Deferiprone had more free radical scavenging power than kojic acid. Generally, deferiprone topical treatment, accelerated wound healing more than kojic acid because of its higher antioxidant and iron chelation abilities.


Assuntos
Antioxidantes/administração & dosagem , Quelantes de Ferro/administração & dosagem , Piridonas/administração & dosagem , Pironas/administração & dosagem , Úlcera Cutânea/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Administração Tópica , Animais , Deferiprona , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Micotoxinas , Ratos , Ratos Wistar , Resultado do Tratamento
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