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1.
Food Chem ; 334: 127613, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711281

RESUMO

The optimization of ultrasound-assisted alkaline extraction and enzymatic deamidation by protein-glutaminase (PG) on evening primrose seed cake (EPSC) protein and its effect on structure (amino acid composition, secondary structure and electrophoresis pattern) and techno-functional properties (water-holding and oil-binding capacities, solubility, emulsifying and foaming properties) of EPSC protein were evaluated. The optimum conditions of the both processes were measured using response surface methodology (RSM). The maximum yield (26.4%) and protein content (86.1%) were reached at the optimized extraction conditions. Optimal conditions of PG deamidation based on reaching a high degree of deamidation (DD) with a simultaneously low degree of hydrolysis (DH). Under these conditions, DD and DH were 39.40 and 2.11%, respectively. Ultrasound-assisted alkaline extraction and enzymatic deamidation by PG have great potential to produce edible EPSC protein with modified techno-functional characteristics that can be used for several aims in the food and pharmaceutical applications.


Assuntos
Fracionamento Químico/métodos , Oenothera biennis/química , Proteínas de Vegetais Comestíveis/química , Amidas/química , Aminoácidos/análise , Emulsificantes/química , Glutaminase/química , Hidrólise , Extratos Vegetais/química , Óleos Vegetais/química , Proteínas de Vegetais Comestíveis/isolamento & purificação , Estrutura Secundária de Proteína , Solubilidade , Ultrassom
2.
BMC Res Notes ; 13(1): 527, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176880

RESUMO

OBJECTIVES: The aim of this study was to use Ligand-based pharmacophore modelling approach for four established antiviral drugs, namely remdesivir, lopinavir, ritonavir and hydroxychloroquine for COVID-19 inhibitors as training sets. In this study Twenty vanillin derivatives together with monolaurin and tetrodotoxin were used as test sets to evaluate as potential SARS-CoV-2 inhibitors. The Structure-based pharmacophore modelling approach was also performed using 5RE6, 5REX and 5RFZ in order to analyse the binding site and ligand-protein complex interactions. RESULTS: The pharmacophore modelling mode of 5RE6 displayed two Hydrogen Bond Acceptors (HBA) and one Hydrophobic (HY) interaction. Besides, the pharmacophore model of 5REX showed two HBA and two HY interactions. Finally, the pharmacophore model of 5RFZ showed three HBA and one HY interaction. Based on ligand-based approach, 20 Schiff-based vanillin derivatives, showed strong MPro inhibition activity. This was due to their good alignment and common features to PDB-5RE6. Similarly, monolaurin and tetrodotoxin displayed some significant activity against SARS-CoV-2. From structure-based approach, vanillin derivatives (1) to (12) displayed some potent MPro inhibition against SARS-CoV-2. Favipiravir, chloroquine and hydroxychloroquine also showed some significant MPro inhibition.


Assuntos
Amidas/farmacologia , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Cloroquina/farmacologia , Hidroxicloroquina/farmacologia , Lauratos/farmacologia , Monoglicerídeos/farmacologia , Pirazinas/farmacologia , Tetrodotoxina/farmacologia , Amidas/química , Antivirais/química , Benzaldeídos/química , Cloroquina/química , Simulação por Computador , Humanos , Hidroxicloroquina/química , Lauratos/química , Testes de Sensibilidade Microbiana , Modelos Moleculares , Monoglicerídeos/química , Pirazinas/química , Relação Estrutura-Atividade , Tetrodotoxina/química
3.
J Oleo Sci ; 69(11): 1403-1409, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33055438

RESUMO

We studied the structures and properties of gel samples prepared by mixtures of N-[3-(dimethylamino)propyl]docosanamide (APA-22) acid salt (APA-22 L-lactic acid), 1-octadecanol (C18OH), and water. The gel samples prepared at the mole ratios [APA-22 L-lactic acid]:C18OH = 1:3, 1:4, and 1:5 yielded two phases; one being the α-gel (α-form hydrated crystal) phase, incorporating a significant quantity of water between lamellar bilayers, and the other being the excess water phase. The lamellar d-spacing remained practically unaltered at these mole ratios, thus maintaining the quantity of water incorporated between the lamellar bilayers relatively constant. Starting at 30°C, the gel samples transformed into a lamellar liquid crystal phase at high temperatures (85°C) and a ß-gel phase at low temperatures (5°C). Interestingly, following dilution by pure water, the viscosity of the gel samples decreased with increasing C18OH content. We expect that the viscosity change affects the performance of the gel samples as hair conditioners.


Assuntos
Amidas/química , Tensoativos/química , Cristalização , Géis , Preparações para Cabelo , Ácido Láctico/química , Bicamadas Lipídicas/química , Ácidos Esteáricos/química , Temperatura , Viscosidade , Água/química
4.
Yakugaku Zasshi ; 140(10): 1225-1233, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999201

RESUMO

This article describes our stereoselective and site-selective chemical methods for exploiting cationic heterocycles as electron-withdrawing groups (EWGs). We envisioned that the phosphoramide N-H proton of a pyridyl phosphoramide 3 would be activated by the cationic pyridinium moiety that is formed upon protonation. The resulting imide-like N-H proton and the acidic pyridinium proton of the pyridinium phosphoramide 3⋅HX cooperate together, making 3⋅HX a highly acidic dual Brønsted acid. The catalytic ability of 3⋅HX was demonstrated in the development of the first asymmetric Diels-Alder reaction between 1-amide dienes and maleimides. Focusing on the activation of N-bromosuccinimide (NBS) because of its structural similarity to maleimides, the enantioselective bromolactonization of trisubstituted olefinic acids was accomplished utilizing pyridyl phosphoramide 3f as a Brønsted base catalyst bearing an acidic N-H proton. Lastly, our strategy for the site-selective acylation of polyol compounds is described. In our system, a pyridine aldoxime ester 10, used as a mild acylating reagent, was activated by a catalytic amount of Lewis acid via the inductive effect of the cationic pyridinium moiety. The resulting metal complex preferentially attracted the alcohol with a Lewis basic site, thereby facilitating selective acylation via a template effect. This metal-template-driven strategy allowed for the site-selective acylation of diverse α-hydroxyamides, including unprotected N-glycolyl aminosugars.


Assuntos
Cátions/química , Cátions/síntese química , Química Orgânica/métodos , Desenvolvimento de Medicamentos/métodos , Elétrons , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Acilação , Amidas/química , Catálise , Complexos de Coordenação/química , Reação de Cicloadição , Ésteres/química , Compostos de Pralidoxima/química , Estereoisomerismo
5.
Nat Commun ; 11(1): 4914, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004788

RESUMO

Oxepinamides are derivatives of anthranilyl-containing tripeptides and share an oxepin ring and a fused pyrimidinone moiety. To the best of our knowledge, no studies have been reported on the elucidation of an oxepinamide biosynthetic pathway and conversion of a quinazolinone to a pyrimidinone-fused 1H-oxepin framework by a cytochrome P450 enzyme in fungal natural product biosynthesis. Here we report the isolation of oxepinamide F from Aspergillus ustus and identification of its biosynthetic pathway by gene deletion, heterologous expression, feeding experiments, and enzyme assays. The nonribosomal peptide synthase (NRPS) OpaA assembles the quinazolinone core with D-Phe incorporation. The cytochrome P450 enzyme OpaB catalyzes alone the oxepin ring formation. The flavoenzyme OpaC installs subsequently one hydroxyl group at the oxepin ring, accompanied by double bond migration. The epimerase OpaE changes the D-Phe residue back to L-form, which is essential for the final methylation by OpaF.


Assuntos
Amidas/metabolismo , Aspergillus/enzimologia , Proteínas Fúngicas/metabolismo , Oxepinas/metabolismo , Amidas/química , Amidas/isolamento & purificação , Aspergillus/genética , Vias Biossintéticas , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Ensaios Enzimáticos , Proteínas Fúngicas/genética , Hidroxilação , Isomerismo , Metilação , Oxepinas/química , Oxepinas/isolamento & purificação , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Fenilalanina/química , Fenilalanina/metabolismo , Proteína O-Metiltransferase/genética , Proteína O-Metiltransferase/metabolismo , Quinazolinonas/metabolismo , Racemases e Epimerases/genética , Racemases e Epimerases/metabolismo
6.
Sci Rep ; 10(1): 14290, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868801

RESUMO

Several drug candidates have been proposed and tested as the latest clinical treatment for coronavirus pneumonia (COVID-19). Chloroquine, hydroxychloroquine, ritonavir/lopinavir, and favipiravir are under trials for the treatment of this disease. The hyperpolarization technique has the ability to further provide a better understanding of the roles of these drugs at the molecular scale and in different applications in the field of nuclear magnetic resonance/magnetic resonance imaging. This technique may provide new opportunities in diagnosis and research of COVID-19. Signal amplification by reversible exchange-based hyperpolarization studies on large-sized drug candidates were carried out. We observed hyperpolarized proton signals from whole structures, due to the unprecedented long-distance polarization transfer by para-hydrogen. We also found that the optimal magnetic field for the maximum polarization transfer yield was dependent on the molecular structure. We can expect further research on the hyperpolarization of other important large molecules, isotope labeling, as well as polarization transfer on nuclei with a long spin relaxation time. A clinical perspective of these features on drug molecules can broaden the application of hyperpolarization techniques for therapeutic studies.


Assuntos
Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/virologia , Descoberta de Drogas , Pneumonia Viral/virologia , Amidas/química , Amidas/farmacologia , Antivirais/química , Cloroquina/química , Cloroquina/farmacologia , Infecções por Coronavirus/diagnóstico , Descoberta de Drogas/métodos , Humanos , Lopinavir/química , Lopinavir/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Pandemias , Pneumonia Viral/diagnóstico , Pirazinas/química , Pirazinas/farmacologia , Ritonavir/química , Ritonavir/farmacologia
7.
PLoS One ; 15(8): e0237358, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790705

RESUMO

OBJECTIVE: To clarify the relationship between amide proton transfer-weighted (APTW) signal, which reflects intracellular pH, and clinico-radiological findings in patients with hyperacute to subacute cerebral infarction. MATERIALS AND METHODS: Twenty-nine patients (median age, 70 years [IQR, 54 to 74]; 15 men) were retrospectively examined. The 10th, 25th, 50th, 75th, and 90th percentiles of APTW signal (APT10, APT25, APT50, APT75 and APT90, respectively) were measured within the infarction region-of-interest (ROI), and compared between poor prognosis and good prognosis groups (modified Rankin Scale [mRS] score ≥2 and mRS score <2, respectively). Correlations between APTW signal and time after onset, lesion size, National Institutes of Health Stroke Scale (NIHSS) score, mRS score, and mean apparent diffusion coefficient (ADC) were evaluated. RESULTS: The poor prognosis group had lower APT50, APT75, and APT90 than the good prognosis group (-0.66 [-1.19 to -0.27] vs. -0.09 [-0.62 to -0.21]; -0.27 [-0.63 to -0.01] vs. 0.31 [-0.15 to 1.06]; 0.06 [-0.21 to 0.34] vs. 0.93 [0.36 to 1.50] %; p <0.05, respectively). APT50 was positively correlated with time after onset (r = 0.37, p = 0.0471) and negatively with lesion size (r = -0.39, p = 0.0388). APT75 and APT90 were negatively correlated with NIHSS (r = -0.41 and -0.43; p <0.05, respectively). APT50, APT75 and APT90 were negatively correlated with mRS (r = -0.37, -0.52 and -0.57; p <0.05, respectively). APT10 and APT25 were positively correlated with mean ADC (r = 0.37 and 0.38; p <0.05, respectively). CONCLUSION: We demonstrated correlations between APTW signals of infarctions and clinico-radiological findings in patients with hyperacute to subacute infarctions. The poor prognosis group had a lower APTW signal than the good prognosis group. APTW signal was reduced in large infarctions, infarctions with low ADC, and in patients with high NIHSS and mRS scores.


Assuntos
Infarto Cerebral/diagnóstico , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Amidas/química , Encéfalo/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Prognóstico , Prótons , Estudos Retrospectivos
8.
J Phys Chem Lett ; 11(19): 8008-8016, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32840378

RESUMO

The pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has quickly spread globally, infecting millions and killing hundreds of thousands of people. Herein, to identify potential antiviral agents, 97 natural amide-like compounds known as alkamides and piperamides were tested against SARS-CoV-2 main protease (Mpro) and RNA-dependent RNA polymerase (RdRp), and the human angiotensin-converting enzyme 2 (ACE2) using molecular docking and molecular dynamics simulations. The docking results showed that alkamides and dimeric piperamides from Piper species have a high binding affinity and potential antiviral activity against SARS-CoV-2. The absorption, distribution, metabolism, and excretion (ADME) profile and Lipinski's rule of five showed that dimeric piperamides have druglikeness potential. The molecular dynamics results showed that pipercyclobutanamide B forms a complex with Mpro at a similar level of stability than N3-I. Our overall results indicate that alkamides and piperamides, and specifically pipercyclobutanamide B, should be further studied as compounds with SARS-CoV-2 antiviral properties.


Assuntos
Amidas/farmacologia , Antivirais/farmacologia , Antivirais/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Piper/química , Pneumonia Viral/tratamento farmacológico , Amidas/química , Amidas/uso terapêutico , Antivirais/farmacocinética , Betacoronavirus/efeitos dos fármacos , Cisteína Endopeptidases , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Pandemias , Peptidil Dipeptidase A/efeitos dos fármacos , Proteínas não Estruturais Virais/antagonistas & inibidores
9.
Mol Cell ; 79(5): 710-727, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32853546

RESUMO

The coronavirus disease 2019 (COVID-19) that is wreaking havoc on worldwide public health and economies has heightened awareness about the lack of effective antiviral treatments for human coronaviruses (CoVs). Many current antivirals, notably nucleoside analogs (NAs), exert their effect by incorporation into viral genomes and subsequent disruption of viral replication and fidelity. The development of anti-CoV drugs has long been hindered by the capacity of CoVs to proofread and remove mismatched nucleotides during genome replication and transcription. Here, we review the molecular basis of the CoV proofreading complex and evaluate its potential as a drug target. We also consider existing nucleoside analogs and novel genomic techniques as potential anti-CoV therapeutics that could be used individually or in combination to target the proofreading mechanism.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Genoma Viral , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , RNA Viral/genética , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/química , Monofosfato de Adenosina/uso terapêutico , Alanina/análogos & derivados , Alanina/química , Alanina/uso terapêutico , Amidas/química , Amidas/uso terapêutico , Antivirais/química , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus/virologia , Humanos , Terapia de Alvo Molecular/métodos , Mutação , Pneumonia Viral/virologia , Pirazinas/química , Pirazinas/uso terapêutico , RNA Viral/antagonistas & inibidores , RNA Viral/metabolismo , Ribonucleosídeos/química , Ribonucleosídeos/uso terapêutico , Índice de Gravidade de Doença , Transcrição Genética , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos
10.
J Nanosci Nanotechnol ; 20(12): 7311-7323, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711596

RESUMO

We started a study on the molecular docking of six potential pharmacologically active inhibitors compounds that can be used clinically against the COVID-19 virus, in this case, remdesivir, ribavirin, favipiravir, galidesivir, hydroxychloroquine and chloroquine interacting with the main COVID-19 protease in complex with a COVID-19 N3 protease inhibitor. The highest values of affinity energy found in order from highest to lowest were chloroquine (CHL), hydroxychloroquine (HYC), favipiravir (FAV), galidesivir (GAL), remdesivir (REM) and ribavirin (RIB). The possible formation of hydrogen bonds, associations through London forces and permanent electric dipole were analyzed. The values of affinity energy obtained for the hydroxychloroquine ligands was -9.9 kcal/mol and for the chloroquine of -10.8 kcal/mol which indicate that the coupling contributes to an effective improvement of the affinity energies with the protease. Indicating that, the position chosen to make the substitutions may be a pharmacophoric group, and cause changes in the protease.


Assuntos
Antivirais/química , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/enzimologia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Cisteína Endopeptidases/química , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/química , Adenina/administração & dosagem , Adenina/análogos & derivados , Adenina/química , Adenina/farmacologia , Monofosfato de Adenosina/administração & dosagem , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/química , Monofosfato de Adenosina/farmacologia , Alanina/administração & dosagem , Alanina/análogos & derivados , Alanina/química , Alanina/farmacologia , Amidas/administração & dosagem , Amidas/química , Amidas/farmacologia , Antivirais/administração & dosagem , Sítios de Ligação , Cloroquina/administração & dosagem , Cloroquina/química , Cloroquina/farmacologia , Interações Medicamentosas , Humanos , Ligação de Hidrogênio , Hidroxicloroquina/administração & dosagem , Hidroxicloroquina/química , Hidroxicloroquina/farmacologia , Ligantes , Simulação de Acoplamento Molecular , Nanotecnologia , Pandemias , Inibidores de Proteases/administração & dosagem , Pirazinas/administração & dosagem , Pirazinas/química , Pirazinas/farmacologia , Pirrolidinas/administração & dosagem , Pirrolidinas/química , Pirrolidinas/farmacologia , Ribavirina/administração & dosagem , Ribavirina/química , Ribavirina/farmacologia , Eletricidade Estática
11.
Chemistry ; 26(51): 11705-11709, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32639618

RESUMO

Chemical exchange saturation transfer (CEST) MRI has recently emerged as a versatile molecular imaging approach in which diamagnetic compounds can be utilized to generate an MRI signal. To expand the scope of CEST MRI applications, herein, we systematically investigated the CEST properties of N-aryl amides with different N-aromatic substitution, revealing their chemical shifts (4.6-5.8 ppm) and exchange rates (up to thousands s-1 ) are favorable to be used as CEST agents as compared to alkyl amides. As the first proof-of-concept study, we used CEST MRI to detect the enzymatic metabolism of the drug acebutolol directly by its intrinsic CEST signal without any chemical labeling. Our study implies that N-aryl amides may enable the label-free CEST MRI detection of the metabolism of many N-aryl amide-containing drugs and a variety of enzymes that act on N-aryl amides, greatly expanding the scope of CEST MR molecular imaging.


Assuntos
Amidas/química , Meios de Contraste/química , Imagem por Ressonância Magnética/métodos , Imagem Molecular
12.
Int J Mol Sci ; 21(11)2020 May 30.
Artigo em Inglês | MEDLINE | ID: covidwho-437471

RESUMO

The novel coronavirus, COVID-19, caused by SARS-CoV-2, is a global health pandemic that started in December 2019. The effective drug target among coronaviruses is the main protease Mpro, because of its essential role in processing the polyproteins that are translated from the viral RNA. In this study, the bioactivity of some selected heterocyclic drugs named Favipiravir (1), Amodiaquine (2), 2'-Fluoro-2'-deoxycytidine (3), and Ribavirin (4) was evaluated as inhibitors and nucleotide analogues for COVID-19 using computational modeling strategies. The density functional theory (DFT) calculations were performed to estimate the thermal parameters, dipole moment, polarizability, and molecular electrostatic potential of the present drugs; additionally, Mulliken atomic charges of the drugs as well as the chemical reactivity descriptors were investigated. The nominated drugs were docked on SARS-CoV-2 main protease (PDB: 6LU7) to evaluate the binding affinity of these drugs. Besides, the computations data of DFT the docking simulation studies was predicted that the Amodiaquine (2) has the least binding energy (-7.77 Kcal/mol) and might serve as a good inhibitor to SARS-CoV-2 comparable with the approved medicines, hydroxychloroquine, and remdesivir which have binding affinity -6.06 and -4.96 Kcal/mol, respectively. The high binding affinity of 2 was attributed to the presence of three hydrogen bonds along with different hydrophobic interactions between the drug and the critical amino acids residues of the receptor. Finally, the estimated molecular electrostatic potential results by DFT were used to illustrate the molecular docking findings. The DFT calculations showed that drug 2 has the highest of lying HOMO, electrophilicity index, basicity, and dipole moment. All these parameters could share with different extent to significantly affect the binding affinity of these drugs with the active protein sites.


Assuntos
Antivirais/farmacologia , Cisteína Endopeptidases/química , Simulação de Acoplamento Molecular , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/química , Amidas/química , Amidas/farmacologia , Amodiaquina/química , Amodiaquina/farmacologia , Antivirais/química , Sítios de Ligação , Cisteína Endopeptidases/metabolismo , Inibidores de Proteases/química , Ligação Proteica , Pirazinas/química , Pirazinas/farmacologia , Ribavirina/química , Ribavirina/farmacologia , Proteínas não Estruturais Virais/metabolismo
13.
Biochim Biophys Acta Proteins Proteom ; 1868(9): 140464, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32497661

RESUMO

The residual solution structures of two alpha-synuclein mutants, A30P and A53T, observed in family members of patients with Parkinson's disease were compared with that of wild-type by NMR. The A53T substitution had been shown to accelerate fibril formation of alpha-synuclein, whereas the A30P mutation has the negative and positive effects on the formation of the fibril and spherical oligomer, respectively. The remaining structure was analyzed via amide-proton exchange and signal intensity measurements using NMR. Amide-proton exchange was used for both the calculation of kex values and ratio of kex at different temperatures. Effects of the A30P (N-terminal region) mutation were observed at the C-terminal region as a more flexible structure, suggesting that long-range interactions exist between the N- and C-terminal regions in alpha-synuclein. In addition, the N-terminal region adopted a more rigid structure in the A53T and A30P mutants than in the wild-type. It was concluded that the structural change caused by the mutations is related to the formation of a beta-hairpin at the initiation site of the N-terminal core structure. Furthermore, the signal intensity was used to estimate the rigidity of the structure. Higher signal intensities were observed for A30P at the 112, 113, and 116 C-terminal residues, suggesting that this region adopts more flexible structure. The ratio of the intensities at different temperatures indicated more flexible or rigid structures in the N-terminal region of A30P than in that of wild-type. Thus, using different approaches and temperatures is a good method to analyze residual structure in intrinsically disordered proteins.


Assuntos
Amidas/química , Proteínas Intrinsicamente Desordenadas/genética , Prótons , alfa-Sinucleína/química , Humanos , Proteínas Intrinsicamente Desordenadas/química , Imagem por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Proteínas Mutantes/química , Mutação , Doença de Parkinson/genética , Estrutura Secundária de Proteína , Temperatura , alfa-Sinucleína/genética
14.
J Med Chem ; 63(13): 7033-7051, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32506913

RESUMO

Mutations in the mitochondrial fusion protein mitofusin (MFN) 2 cause the chronic neurodegenerative condition Charcot-Marie-Tooth disease type 2A (CMT2A), for which there is currently no treatment. Small-molecule activators of MFN1 and MFN2 enhance mitochondrial fusion and offer promise as therapy for this condition, but prototype compounds have poor pharmacokinetic properties. Herein, we describe a rational design of a series of 6-phenylhexanamide derivatives whose pharmacokinetic optimization yielded a 4-hydroxycyclohexyl analogue, 13, with the potency, selectivity, and oral bioavailability of a preclinical candidate. Studies of 13 cis- and trans-4-hydroxycyclohexyl isostereomers unexpectedly revealed functionality and protein engagement exclusively for the trans form, 13B. Preclinical absorption, distribution, metabolism, and excretion (ADME) and in vivo target engagement studies of 13B support further development of 6-phenylhexanamide derivatives as therapeutic agents for human CMT2A.


Assuntos
Amidas/química , Amidas/farmacologia , Desenho de Fármacos , GTP Fosfo-Hidrolases/metabolismo , Doenças Mitocondriais/tratamento farmacológico , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas Mitocondriais/metabolismo , Amidas/farmacocinética , Amidas/uso terapêutico , Animais , Camundongos , Estereoisomerismo , Especificidade por Substrato , Distribuição Tecidual
15.
Int J Mol Sci ; 21(11)2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32486229

RESUMO

The novel coronavirus, COVID-19, caused by SARS-CoV-2, is a global health pandemic that started in December 2019. The effective drug target among coronaviruses is the main protease Mpro, because of its essential role in processing the polyproteins that are translated from the viral RNA. In this study, the bioactivity of some selected heterocyclic drugs named Favipiravir (1), Amodiaquine (2), 2'-Fluoro-2'-deoxycytidine (3), and Ribavirin (4) was evaluated as inhibitors and nucleotide analogues for COVID-19 using computational modeling strategies. The density functional theory (DFT) calculations were performed to estimate the thermal parameters, dipole moment, polarizability, and molecular electrostatic potential of the present drugs; additionally, Mulliken atomic charges of the drugs as well as the chemical reactivity descriptors were investigated. The nominated drugs were docked on SARS-CoV-2 main protease (PDB: 6LU7) to evaluate the binding affinity of these drugs. Besides, the computations data of DFT the docking simulation studies was predicted that the Amodiaquine (2) has the least binding energy (-7.77 Kcal/mol) and might serve as a good inhibitor to SARS-CoV-2 comparable with the approved medicines, hydroxychloroquine, and remdesivir which have binding affinity -6.06 and -4.96 Kcal/mol, respectively. The high binding affinity of 2 was attributed to the presence of three hydrogen bonds along with different hydrophobic interactions between the drug and the critical amino acids residues of the receptor. Finally, the estimated molecular electrostatic potential results by DFT were used to illustrate the molecular docking findings. The DFT calculations showed that drug 2 has the highest of lying HOMO, electrophilicity index, basicity, and dipole moment. All these parameters could share with different extent to significantly affect the binding affinity of these drugs with the active protein sites.


Assuntos
Antivirais/farmacologia , Cisteína Endopeptidases/química , Simulação de Acoplamento Molecular , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/química , Amidas/química , Amidas/farmacologia , Amodiaquina/química , Amodiaquina/farmacologia , Antivirais/química , Sítios de Ligação , Cisteína Endopeptidases/metabolismo , Inibidores de Proteases/química , Ligação Proteica , Pirazinas/química , Pirazinas/farmacologia , Ribavirina/química , Ribavirina/farmacologia , Proteínas não Estruturais Virais/metabolismo
16.
J Phys Chem Lett ; 11(11): 4430-4435, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: covidwho-233085

RESUMO

The pandemic outbreak of a new coronavirus (CoV), SARS-CoV-2, has captured the world's attention, demonstrating that CoVs represent a continuous global threat. As this is a highly contagious virus, it is imperative to understand RNA-dependent-RNA-polymerase (RdRp), the key component in virus replication. Although the SARS-CoV-2 genome shares 80% sequence identity with severe acute respiratory syndrome SARS-CoV, their RdRps and nucleotidyl-transferases (NiRAN) share 98.1% and 93.2% identity, respectively. Sequence alignment of six coronaviruses demonstrated higher identity among their RdRps (60.9%-98.1%) and lower identity among their Spike proteins (27%-77%). Thus, a 3D structural model of RdRp, NiRAN, non-structural protein 7 (nsp7), and nsp8 of SARS-CoV-2 was generated by modeling starting from the SARS counterpart structures. Furthermore, we demonstrate the binding poses of three viral RdRp inhibitors (Galidesivir, Favipiravir, and Penciclovir), which were recently reported to have clinical significance for SARS-CoV-2. The network of interactions established by these drug molecules affirms their efficacy to inhibit viral RNA replication and provides an insight into their structure-based rational optimization for SARS-CoV-2 inhibition.


Assuntos
Betacoronavirus/enzimologia , Nucleotidiltransferases/química , RNA Replicase/química , Adenina/análogos & derivados , Adenina/química , Adenina/metabolismo , Amidas/química , Amidas/metabolismo , Antivirais/química , Antivirais/metabolismo , Betacoronavirus/isolamento & purificação , Sítios de Ligação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Humanos , Simulação de Acoplamento Molecular , Nucleotidiltransferases/metabolismo , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Estrutura Terciária de Proteína , Pirazinas/química , Pirazinas/metabolismo , Pirrolidinas/química , Pirrolidinas/metabolismo , RNA Replicase/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-32361466

RESUMO

The venom of Crotalus durissus terrificus (Cdt) is a source of a wide variety of toxins, some of them with interesting pharmacological applications. Of these toxins, the phospholipase A2 (PLA2) subunit of crotoxin (Ctx) has been studied for its potential as an antiviral and antibacterial agent. Peptides have proven useful ligands for the purification of numerous molecules, including antibodies, toxins, enzymes and other proteins. Here, we sought to use a phosphopeptide (P-Lys) as a ligand for PLA2 purification. P-Lys was synthesized in solid phase on Rink-Amide-ChemMatrix resin, immobilized on NHS-agarose, and then evaluated as a chromatographic matrix. Under the best conditions, total protein adsorption reached 39% and only the eluate fraction presented PLA2 activity. Analysis of the eluate by SDS-PAGE showed three bands, one corresponding to the molecular weight of PLA2 (14 kDa). Said bands were analyzed by mass spectrometry and identified as PLA2 and its multimers. The final product showed a purity of over 90%. In addition, slightly changing the process conditions also allowed the isolation of crotamine.


Assuntos
Cromatografia de Afinidade/métodos , Venenos de Crotalídeos/análise , Fosfolipases A2/análise , Fosfopeptídeos/química , Amidas/química , Animais , Crotalus , Crotoxina/química , Ligantes , Espectrometria de Massas , Sefarose/química , Técnicas de Síntese em Fase Sólida , Succinimidas/química
18.
J Chromatogr A ; 1622: 461132, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32402494

RESUMO

A novel and simple derivatization method using a series of amide acetals as derivatization reagents, along with gas chromatography tandem mass spectrometry (GC-MS/MS) analysis, were developed and validated for simultaneous determination of 9 perfluoroalkyl carboxylic acids (PFCAs) in this study. The structures and fragmentation pathway of PFCAs derivatives were deduced and verified. The derivatization method developed in this study improved the sensitivity of the detection of PFCAs by GC. The applicability of 6 amide acetals for the derivatization of PFCAs was demonstrated. Derivatization conditions for 9 PFCAs were optimized with addition of 20 µL of derivatization reagent and reaction at 35 °C for 30 min. 9 PFCAs derivatives were confirmed to be stable over 15 days. The instrument detection limits (IDLs) were lower than 0.01 pg/µL. The intra and inter-day precisions were below 4.06% and 5.48%, respectively. To demonstrate the utility of the derivatization method, the level of PFCAs in the marine products were detected. The alkaline digestion followed by solid-phase extraction (SPE) cleanup method was used for pretreatment. The method detection limits (MDLs) ranged from 0.04 to 0.10 ng/g, and the spiked recoveries ranged between 54.72% and 107.29%, with relative standard deviation (RSD) of 1.53%-11.89%. Five PFCAs were detected in the range of 0.66 to 499.03 ng/g dry weight.


Assuntos
Acetais/química , Amidas/química , Ácidos Carboxílicos/análise , Fluorcarbonetos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Organismos Aquáticos/química , Dimetilformamida/química , Limite de Detecção , Padrões de Referência
19.
J Phys Chem Lett ; 11(11): 4430-4435, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32392072

RESUMO

The pandemic outbreak of a new coronavirus (CoV), SARS-CoV-2, has captured the world's attention, demonstrating that CoVs represent a continuous global threat. As this is a highly contagious virus, it is imperative to understand RNA-dependent-RNA-polymerase (RdRp), the key component in virus replication. Although the SARS-CoV-2 genome shares 80% sequence identity with severe acute respiratory syndrome SARS-CoV, their RdRps and nucleotidyl-transferases (NiRAN) share 98.1% and 93.2% identity, respectively. Sequence alignment of six coronaviruses demonstrated higher identity among their RdRps (60.9%-98.1%) and lower identity among their Spike proteins (27%-77%). Thus, a 3D structural model of RdRp, NiRAN, non-structural protein 7 (nsp7), and nsp8 of SARS-CoV-2 was generated by modeling starting from the SARS counterpart structures. Furthermore, we demonstrate the binding poses of three viral RdRp inhibitors (Galidesivir, Favipiravir, and Penciclovir), which were recently reported to have clinical significance for SARS-CoV-2. The network of interactions established by these drug molecules affirms their efficacy to inhibit viral RNA replication and provides an insight into their structure-based rational optimization for SARS-CoV-2 inhibition.


Assuntos
Betacoronavirus/enzimologia , Nucleotidiltransferases/química , RNA Replicase/química , Adenina/análogos & derivados , Adenina/química , Adenina/metabolismo , Amidas/química , Amidas/metabolismo , Antivirais/química , Antivirais/metabolismo , Betacoronavirus/isolamento & purificação , Sítios de Ligação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Humanos , Simulação de Acoplamento Molecular , Nucleotidiltransferases/metabolismo , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Estrutura Terciária de Proteína , Pirazinas/química , Pirazinas/metabolismo , Pirrolidinas/química , Pirrolidinas/metabolismo , RNA Replicase/metabolismo
20.
Parasitol Res ; 119(6): 1879-1887, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32382989

RESUMO

Malaria, caused by protozoa of the genus Plasmodium, is a disease that infects hundreds of millions of people annually, causing an enormous social burden in many developing countries. Since current antimalarial drugs are starting to face resistance by the parasite, the development of new therapeutic options has been prompted. The enzyme Plasmodium falciparum enoyl-ACP reductase (PfENR) has a determinant role in the fatty acid biosynthesis of this parasite and is absent in humans, making it an ideal target for new antimalarial drugs. In this sense, the present study aimed at evaluating the in silico binding affinity of natural and synthetic amides through molecular docking, in addition to their in vitro activity against P. falciparum by means of the SYBR Green Fluorescence Assay. The in vitro results revealed that the natural amide piplartine (1a) presented partial antiplasmodial activity (20.54 µM), whereas its synthetic derivatives (1m-IC50 104.45 µM), (1b, 1g, 1k, and 14f) and the natural amide piperine (18a) were shown to be inactive (IC50 > 200 µM). The in silico physicochemical analyses demonstrated that compounds 1m and 14f violated the Lipinski's rule of five. The in silico analyses showed that 14f presented the best binding affinity (- 13.047 kcal/mol) to PfENR and was also superior to the reference inhibitor triclosan (- 7.806 kcal/mol). In conclusion, we found that the structural modifications in 1a caused a significant decrease in antiplasmodial activity. Therefore, new modifications are encouraged in order to improve the activity observed.


Assuntos
Amidas/farmacologia , Antimaláricos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Amidas/química , Animais , Chlorocebus aethiops , Simulação por Computador , Enoil-(Proteína de Transporte de Acila) Redutase (NADH)/antagonistas & inibidores , Enoil-(Proteína de Transporte de Acila) Redutase (NADH)/metabolismo , Células Hep G2 , Humanos , Malária Falciparum , Simulação de Acoplamento Molecular , Piper nigrum , Plasmodium falciparum/enzimologia , Triclosan/farmacologia , Células Vero
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