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1.
Nat Commun ; 11(1): 4282, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855413

RESUMO

The main protease, Mpro (or 3CLpro) in SARS-CoV-2 is a viable drug target because of its essential role in the cleavage of the virus polypeptide. Feline infectious peritonitis, a fatal coronavirus infection in cats, was successfully treated previously with a prodrug GC376, a dipeptide-based protease inhibitor. Here, we show the prodrug and its parent GC373, are effective inhibitors of the Mpro from both SARS-CoV and SARS-CoV-2 with IC50 values in the nanomolar range. Crystal structures of SARS-CoV-2 Mpro with these inhibitors have a covalent modification of the nucleophilic Cys145. NMR analysis reveals that inhibition proceeds via reversible formation of a hemithioacetal. GC373 and GC376 are potent inhibitors of SARS-CoV-2 replication in cell culture. They are strong drug candidates for the treatment of human coronavirus infections because they have already been successful in animals. The work here lays the framework for their use in human trials for the treatment of COVID-19.


Assuntos
Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Coronavirus Felino/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Células A549 , Animais , Antivirais/química , Betacoronavirus/enzimologia , Sítios de Ligação , Chlorocebus aethiops , Coronavirus Felino/enzimologia , Cristalografia por Raios X , Cisteína Endopeptidases/química , Efeito Citopatogênico Viral/efeitos dos fármacos , Reposicionamento de Medicamentos , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Pró-Fármacos , Inibidores de Proteases/química , Pirrolidinas/química , Pirrolidinas/farmacologia , Vírus da SARS/efeitos dos fármacos , Vírus da SARS/enzimologia , Células Vero , Proteínas não Estruturais Virais/química , Replicação Viral/efeitos dos fármacos
2.
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
3.
Virus Res ; 288: 198102, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32717346

RESUMO

Coronavirus disease 2019 (COVID-19) is an infectious disease, caused by a newly emerged highly pathogenic virus called novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Targeting the main protease (Mpro, 3CLpro) of SARS-CoV-2 is an appealing approach for drug development because this enzyme plays a significant role in the viral replication and transcription. The available crystal structures of SARS-CoV-2 Mpro determined in the presence of different ligands and inhibitor-like compounds provide a platform for the quick development of selective inhibitors of SARS-CoV-2 Mpro. In this study, we utilized the structural information of co-crystallized SARS-CoV-2 Mpro for the structure-guided drug discovery of high-affinity inhibitors from the PubChem database. The screened compounds were selected on the basis of their physicochemical properties, drug-likeliness, and strength of affinity to the SARS-CoV-2 Mpro. Finally, we have identified 6-Deaminosinefungin (PubChem ID: 10428963) and UNII-O9H5KY11SV (PubChem ID: 71481120) as potential inhibitors of SARS-CoV-2 Mpro which may be further exploited in drug development to address SARS-CoV-2 pathogenesis. Both compounds are structural analogs of known antivirals, having considerable protease inhibitory potential with improved pharmacological properties. All-atom molecular dynamics simulations suggested SARS-CoV-2 Mpro in complex with these compounds is stable during the simulation period with minimal structural changes. This work provides enough evidence for further implementation of the identified compounds in the development of effective therapeutics of COVID-19.


Assuntos
Aminoglicosídeos/química , Antivirais/química , Betacoronavirus/química , Inibidores de Proteases/química , Pirrolidinas/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Aminoglicosídeos/metabolismo , Antivirais/metabolismo , Betacoronavirus/enzimologia , Domínio Catalítico , Infecções por Coronavirus/tratamento farmacológico , Cisteína Endopeptidases/química , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Descoberta de Drogas , Expressão Gênica , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Pandemias , Pneumonia Viral/tratamento farmacológico , Inibidores de Proteases/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Pirrolidinas/metabolismo , Especificidade por Substrato , Termodinâmica , Interface Usuário-Computador , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-32669265

RESUMO

The coronavirus (CoV) disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome CoV-2 (SARS-CoV-2) is a health threat worldwide. Viral main protease (Mpro, also called 3C-like protease [3CLpro]) is a therapeutic target for drug discovery. Herein, we report that GC376, a broad-spectrum inhibitor targeting Mpro in the picornavirus-like supercluster, is a potent inhibitor for the Mpro encoded by SARS-CoV-2, with a half-maximum inhibitory concentration (IC50) of 26.4 ± 1.1 nM. In this study, we also show that GC376 inhibits SARS-CoV-2 replication with a half-maximum effective concentration (EC50) of 0.91 ± 0.03 µM. Only a small portion of SARS-CoV-2 Mpro was covalently modified in the excess of GC376 as evaluated by mass spectrometry analysis, indicating that improved inhibitors are needed. Subsequently, molecular docking analysis revealed that the recognition and binding groups of GC376 within the active site of SARS-CoV-2 Mpro provide important new information for the optimization of GC376. Given that sufficient safety and efficacy data are available for GC376 as an investigational veterinary drug, expedited development of GC376, or its optimized analogues, for treatment of SARS-CoV-2 infection in human is recommended.


Assuntos
Antivirais/química , Betacoronavirus/efeitos dos fármacos , Cisteína Endopeptidases/química , Inibidores de Proteases/química , Pirrolidinas/química , Proteínas não Estruturais Virais/química , Motivos de Aminoácidos , Animais , Antivirais/farmacologia , Betacoronavirus/patogenicidade , Domínio Catalítico , Chlorocebus aethiops , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Expressão Gênica , Simulação de Acoplamento Molecular , Inibidores de Proteases/farmacologia , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Pirrolidinas/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Termodinâmica , Células Vero , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos
5.
Cell Res ; 30(8): 678-692, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32541865

RESUMO

A new coronavirus SARS-CoV-2, also called novel coronavirus 2019 (2019-nCoV), started to circulate among humans around December 2019, and it is now widespread as a global pandemic. The disease caused by SARS-CoV-2 virus is called COVID-19, which is highly contagious and has an overall mortality rate of 6.35% as of May 26, 2020. There is no vaccine or antiviral available for SARS-CoV-2. In this study, we report our discovery of inhibitors targeting the SARS-CoV-2 main protease (Mpro). Using the FRET-based enzymatic assay, several inhibitors including boceprevir, GC-376, and calpain inhibitors II, and XII were identified to have potent activity with single-digit to submicromolar IC50 values in the enzymatic assay. The mechanism of action of the hits was further characterized using enzyme kinetic studies, thermal shift binding assays, and native mass spectrometry. Significantly, four compounds (boceprevir, GC-376, calpain inhibitors II and XII) inhibit SARS-CoV-2 viral replication in cell culture with EC50 values ranging from 0.49 to 3.37 µM. Notably, boceprevir, calpain inhibitors II and XII represent novel chemotypes that are distinct from known substrate-based peptidomimetic Mpro inhibitors. A complex crystal structure of SARS-CoV-2 Mpro with GC-376, determined at 2.15 Å resolution with three protomers per asymmetric unit, revealed two unique binding configurations, shedding light on the molecular interactions and protein conformational flexibility underlying substrate and inhibitor binding by Mpro. Overall, the compounds identified herein provide promising starting points for the further development of SARS-CoV-2 therapeutics.


Assuntos
Antivirais/farmacologia , Betacoronavirus/enzimologia , Infecções por Coronavirus/metabolismo , Glicoproteínas/farmacologia , Pneumonia Viral/metabolismo , Prolina/análogos & derivados , Pirrolidinas/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos , Células A549 , Animais , Antivirais/química , Células CACO-2 , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Descoberta de Drogas/métodos , Humanos , Concentração Inibidora 50 , Cinética , Pandemias , Pneumonia Viral/virologia , Prolina/farmacologia , Conformação Proteica , Pirrolidinas/química , Células Vero , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo
6.
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
7.
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
8.
Toxicol Lett ; 331: 42-52, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464236

RESUMO

Synthetic cathinones abuse remains a serious public health problem. Kidney injury has been reported in intoxications associated with synthetic cathinones, but the molecular mechanisms involved have not been explored yet. In this study, the potential in vitro nephrotoxic effects of four commonly abused cathinone derivatives, namely pentedrone, 3,4-dimethylmethcatinone (3,4-DMMC), methylone and 3,4-methylenedioxypyrovalerone (MDPV), were assessed in the human kidney HK-2 cell line. All four derivatives elicited cell death in a concentration- and time-dependent manner, in the following order of potency: 3,4-DMMC >> MDPV > methylone ≈ pentedrone. 3,4-DMMC and methylone were selected to further elucidate the mechanisms behind synthetic cathinones-induced cell death. Both drugs elicited apoptotic cell death and prompted the formation of acidic vesicular organelles and autophagosomes in HK-2 cells. Moreover, the autophagy inhibitor 3-methyladenine significantly potentiated cell death, indicating that autophagy may serve as a cell survival mechanism that protects renal cells against synthetic cathinones toxicity. Both drugs triggered a rise in reactive oxygen and nitrogen species formation, which was completely prevented by antioxidant treatment with N­acetyl­L­cysteine or ascorbic acid. Importantly, these antioxidant agents significantly aggravated renal cell death induced by cathinone derivatives, most likely due to their autophagy-blocking properties. Taken together, our results support an intricate control of cell survival/death modulated by oxidative stress, apoptosis and autophagy in synthetic cathinones-induced renal injury.


Assuntos
Alcaloides/toxicidade , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Drogas Ilícitas/toxicidade , Rim/efeitos dos fármacos , Alcaloides/química , Benzodioxóis/química , Benzodioxóis/toxicidade , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Rim/metabolismo , Rim/patologia , Metanfetamina/análogos & derivados , Metanfetamina/química , Metanfetamina/toxicidade , Metilaminas/química , Metilaminas/toxicidade , Pentanonas/química , Pentanonas/toxicidade , Pirrolidinas/química , Pirrolidinas/toxicidade , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
9.
Pharm Res ; 37(6): 94, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32405662

RESUMO

PURPOSE: An investigation of underlying mechanisms of API-polymer interaction patterns has the potential to provide valuable insights for selecting appropriate formulations with superior physical stability and processability. MATERIALS AND METHODS: In this study, copovidone was used as a polymeric carrier for several model compounds including clotrimazole, nifedipine, and posaconazole. The varied chemical structures conferred the ability for the model compounds to form distinct interactions with copovidone. Rheology and nuclear magnetic resonance (NMR) were combined to investigate the molecular pattern and relative strength of active pharmaceutical ingredient (API)-polymer interactions. In addition, the impact of the interactions on formulation processability via hot melt extrusion (HME) and physical stability were evaluated. RESULTS: The rheological response of an API-polymer system was found to be highly sensitive to API-polymer interaction, depending both on API chemistry and API-polymer miscibility. In the systems studied, dispersed API induced a stronger plasticizer effect on the polymer matrix compared to crystalline/aggregated API. Correspondingly, the processing torque via HME showed a proportional relationship with the maximum complex viscosity of the API-polymer system. In order to quantitatively evaluate the relative strength of the API-polymer interaction, homogeneously dispersed API-polymer amorphous samples were prepared by HME at an elevated temperature. DSC, XRD, and rheology were employed to confirm the amorphous integrity and homogeneity of the resultant extrudates. Subsequently, the homogeneously dispersed API-polymer amorphous dispersions were interrogated by rheology and NMR to provide a qualitative and quantitative assessment of the nature of the API-polymer interaction, both macroscopically and microscopically. Rheological master curves of frequency sweeps of the extrudates exhibited a strong dependence on the API chemistry and revealed a rank ordering of the relative strength of API-copovidone interactions, in the order of posaconazole > nifedipine > clotrimazole. NMR data provided the means to precisely map the API-polymer interaction pattern and identify the specific sites of interaction from a molecular perspective. Finally, the impact of API-polymer interactions on the physical stability of the resultant extrudates was studied. CONCLUSION: Qualitative and quantitative evaluation of the relative strength of the API-polymer interaction was successfully accomplished by utilizing combined rheology and NMR. Graphical Abstract.


Assuntos
Clotrimazol/química , Portadores de Fármacos/química , Nifedipino/química , Pirrolidinas/química , Triazóis/química , Compostos de Vinila/química , Composição de Medicamentos , Liberação Controlada de Fármacos , Elasticidade , Tecnologia de Extrusão por Fusão a Quente , Temperatura Alta , Espectroscopia de Ressonância Magnética , Conformação Molecular , Reologia , Relação Estrutura-Atividade , Viscosidade
10.
Pharm Res ; 37(4): 70, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32185516

RESUMO

PURPOSE: While including amorphous solid dispersion (ASD) in tablet formulations is increasingly common, tablets containing high ASD loading are associated with slow disintegration, which presents a challenge to control pill burden for less potent compounds. METHODS: We use a model ASD, composed of a hydrophobic drug with copovidone and a non-ionic surfactant, to explore formulation options that can prevent slow disintegration. RESULTS: In addition to the ASD loading, the pH of the disintegration medium and the inclusion of inorganic salts in the tablet also have an impact on the tablet disintegration time. Certain kosmotropic salts, when added in the formulation, can significantly accelerate tablet disintegration, though the rank order in their effectiveness does not exactly follow the Hofmeister series at pH 1.8. The particle size and dissolution rate of the salt can contribute to its overall effectiveness. CONCLUSION: We provided a mechanistic explanation of the disintegration process: fast-dissolving kosmotropic salt results in a concentrated salt solution inside the restrained tablet matrix, thus inhibiting the dissolution of copovidone and preventing polymer gelling which is the main cause leading the slow disintegration. The outcome of this study has enabled the design of a higher ASD loading platform formulation for copovidone based ASD. Graphical Abstract MicroCT aids the mechanistic understanding of the role of inorganic salt in the tablet disintegration of amorphous solid dispersion based formulation.


Assuntos
Pirrolidinas/química , Sais/química , Comprimidos/química , Compostos de Vinila/química , Química Farmacêutica , Excipientes/química , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Concentração Osmolar , Tamanho da Partícula , Solubilidade
11.
Nat Commun ; 11(1): 1145, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32123179

RESUMO

Recent studies show that GPCRs rapidly interconvert between multiple states although our ability to interrogate, monitor and visualize them is limited by a relative lack of suitable tools. We previously reported two nanobodies (Nb39 and Nb6) that stabilize distinct ligand- and efficacy-delimited conformations of the kappa opioid receptor. Here, we demonstrate via X-ray crystallography a nanobody-targeted allosteric binding site by which Nb6 stabilizes a ligand-dependent inactive state. As Nb39 stabilizes an active-like state, we show how these two state-dependent nanobodies can provide real-time reporting of ligand stabilized states in cells in situ. Significantly, we demonstrate that chimeric GPCRs can be created with engineered nanobody binding sites to report ligand-stabilized states. Our results provide both insights regarding potential mechanisms for allosterically modulating KOR with nanobodies and a tool for reporting the real-time, in situ dynamic range of GPCR activity.


Assuntos
Receptores Opioides kappa/química , Receptores Opioides kappa/metabolismo , Anticorpos de Domínio Único/química , Sítio Alostérico , Sítios de Ligação , Técnicas Biossensoriais , Cristalografia por Raios X , AMP Cíclico/metabolismo , Dinorfinas/química , Dinorfinas/farmacologia , Células HEK293 , Humanos , Medições Luminescentes/métodos , Piperazinas/química , Piperazinas/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Conformação Proteica , Pirrolidinas/química , Pirrolidinas/farmacologia , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Anticorpos de Domínio Único/metabolismo , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/farmacologia
12.
Molecules ; 25(3)2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32012808

RESUMO

A simple and highly sensitive method is developed for the simultaneous determination of Ni2+, Cr2O72-, Co2+, and Hg2+ by using in syringe low density solvent-dispersive liquid liquid microextraction (ISLD-DLLME), followed by high performance liquid chromatography with a UV detector. The four metal ions were derivatized with pyrrolidine dithiocarbamate (PDC) based on complexation before their enrichment by ISLD-DLLME in which 1-octanol and methanol were used as the extraction solvent and the dispersive solvent, respectively. The extraction was performed in a commercially available syringe under vortex agitation. Phase separation was achieved without centrifugation, and the extraction phase was easily collected by moving the syringe plunger. Parameters affecting the extraction efficiency were studied and optimized. Under the optimum conditions, the four metal-PDC complexes were detected within 18 min, and ISLD-DLLME could increase the detection sensitivity in the range of 64-230 times compared to the direct HPLC analysis. The obtained limits of detection (LODs) were found to be in the range of 0.011-2.0 µg L-1. The applicability of the method is demonstrated for freshwater fish, shrimp, and shellfish samples. In addition, the results are in good agreement with those obtained by inductively-coupled plasma-optical emission spectrometry (ICP-OES).


Assuntos
Contaminação de Alimentos/análise , Microextração em Fase Líquida/instrumentação , Metais/análise , Animais , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Pirrolidinas/química , Solventes/química , Seringas , Tiocarbamatos/química
13.
Carbohydr Res ; 489: 107931, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32088502

RESUMO

A glycal based synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-ones proceeding through a common intermediate is reported. The key step in the work presented here is a two-step conversion of 4,6-di-O-benzyl-d-glucal to 2,3-dideoxy-2-tosylamido-d-glucose. This manuscript reports the first carbohydrate based approach to the synthesis of (+)-bulgecinine and the whole sequence has been accomplished with complete stereochemical integrity without the formation of mixture of products in any of these steps.


Assuntos
Carboidratos/química , Glicopeptídeos/síntese química , Pirrolidinas/síntese química , Alcaloides de Pirrolizidina/síntese química , Glicopeptídeos/química , Conformação Molecular , Pirrolidinas/química , Alcaloides de Pirrolizidina/química , Estereoisomerismo
14.
Biochemistry ; 59(7): 831-835, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32022543

RESUMO

Transition state analogue inhibitor design (TSID) and fragment-based drug design (FBDD) are drug design approaches typically used independently. Methylthio-DADMe-Immucillin-A (MTDIA) is a tight-binding transition state analogue of bacterial 5'-methylthioadenosine nucleosidases (MTANs). Previously, Salmonella enterica MTAN structures were found to bind MTDIA and ethylene glycol fragments, but MTDIA modified to contain similar fragments did not enhance affinity. Seventy-five published MTAN structures were analyzed, and co-crystallization fragments were found that might enhance the binding of MTDIA to other bacterial MTANs through contacts external to MTDIA binding. The fragment-modified MTDIAs were tested with Helicobacter pylori MTAN and Staphylococcus aureus MTANs (HpMTAN and SaMTAN) as test cases to explore inhibitor optimization by potential contacts beyond the transition state contacts. Replacement of a methyl group with a 2'-ethoxyethanol group in MTDIA improved the dissociation constant 14-fold (0.09 nM vs 1.25 nM) for HpMTAN and 81-fold for SaMTAN (0.096 nM vs 7.8 nM). TSID combined with FBDD can be useful in enhancing already powerful inhibitors.


Assuntos
Adenina/análogos & derivados , Proteínas de Bactérias/metabolismo , Inibidores Enzimáticos/metabolismo , Purina-Núcleosídeo Fosforilase/metabolismo , Pirrolidinas/metabolismo , Adenina/química , Adenina/metabolismo , Bactérias/enzimologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Domínio Catalítico , Inibidores Enzimáticos/química , Polietilenoglicóis/química , Polietilenoglicóis/metabolismo , Ligação Proteica , Purina-Núcleosídeo Fosforilase/antagonistas & inibidores , Purina-Núcleosídeo Fosforilase/química , Pirrolidinas/química
15.
Molecules ; 25(4)2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32059504

RESUMO

The synthesis of an unreported 2-aminopyrrolidine-1-carboxamidine unit is here described for the first time. This unusual and promising structure was attained through the oxidative decarboxylation of amino acids using the pair of reagents, silver(I)/peroxydisulfate (Ag(I)/S2O82-) followed by intermolecular (in the case of l-proline derivative) and intramolecular trapping (in the case of acyl l-arginine) by N-nucleophiles. The l-proline approach has a broader scope for the synthesis of 2-aminopyrrolidine-1-carboxamidine derivatives, whereas the intramolecular cyclization afforded by the l-acylarginines, when applied, results in higher yields. The former allowed the first synthesis of cernumidine, a natural alkaloid isolated in 2011 from Solanum cernuum Vell, as its racemic form.


Assuntos
Guanina/síntese química , Estrutura Molecular , Pirrolidinas/síntese química , Alcaloides/síntese química , Alcaloides/química , Aminas/química , Ciclização , Descarboxilação , Guanina/química , Oxirredução , Pirrolidinas/química , Prata/química
16.
Viruses ; 12(2)2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-32098094

RESUMO

Porcine epidemic diarrhea virus (PEDV), being highly virulent and contagious in piglets, has caused significant damage to the pork industries of many countries worldwide. There are no commercial drugs targeting coronaviruses (CoVs), and few studies on anti-PEDV inhibitors. The coronavirus 3C-like protease (3CLpro) has a conserved structure and catalytic mechanism and plays a key role during viral polyprotein processing, thus serving as an appealing antiviral drug target. Here, we report the anti-PEDV effect of the broad-spectrum inhibitor GC376 (targeting 3Cpro or 3CLpro of viruses in the picornavirus-like supercluster). GC376 was highly effective against the PEDV 3CLpro and exerted similar inhibitory effects on two PEDV strains. Furthermore, the structure of the PEDV 3CLpro in complex with GC376 was determined at 1.65 Å. We elucidated structural details and analyzed the differences between GC376 binding with the PEDV 3CLpro and GC376 binding with the transmissible gastroenteritis virus (TGEV) 3CLpro. Finally, we explored the substrate specificity of PEDV 3CLpro at the P2 site and analyzed the effects of Leu group modification in GC376 on inhibiting PEDV infection. This study helps us to understand better the PEDV 3CLpro substrate specificity, providing information on the optimization of GC376 for development as an antiviral therapeutic against coronaviruses.


Assuntos
Antivirais/farmacologia , Peptídeo Hidrolases/química , Vírus da Diarreia Epidêmica Suína/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Pirrolidinas/farmacologia , Animais , Antivirais/química , Antivirais/metabolismo , Domínio Catalítico , Chlorocebus aethiops , Cristalografia por Raios X , Modelos Moleculares , Peptídeo Hidrolases/metabolismo , Vírus da Diarreia Epidêmica Suína/enzimologia , Vírus da Diarreia Epidêmica Suína/fisiologia , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Pirrolidinas/química , Pirrolidinas/metabolismo , Especificidade por Substrato , Vírus da Gastroenterite Transmissível/enzimologia , Células Vero , Replicação Viral/efeitos dos fármacos
17.
Eur J Med Chem ; 188: 112034, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31927314

RESUMO

A new library of pyrido-pyrrolidine hybrid compounds were designed, developed and screened for their antidiabetic property with α-glucosidase. The design is based on preliminary screening of key fragments identified from literature reported α-glucosidase inhibitors and antidiabetic compounds. The most active fragments were stitched to provide a pyrido-pyrrolidine hybrid molecule as a new motif. A library of these compounds were synthesized and screened against a series of α-glycosidases. Subsequently, compound 3k was the most efficacious analog with IC50 of 0.56 µM. Photoluminescence study and circular dichroism experiments indicated that compound 3k modulates the primary and secondary structure of the enzyme. It successfully brings down the fasting blood glucose level for streptozotocin (STZ, 70 mg/kg, Intraperitoneal) induced type I diabetic male Sprague-Dawley rats (250-320 g). At lower concentration, compound 3k slightly stimulates proliferation of BRIN-BD11 (α-glucose responsive beta cells from rat pancreas islets that secretes insulin) cells.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Descoberta de Drogas , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/farmacologia , Pirrolidinas/farmacologia , alfa-Glucosidases/metabolismo , Animais , Sítios de Ligação/efeitos dos fármacos , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/metabolismo , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/sangue , Inibidores de Glicosídeo Hidrolases/química , Humanos , Hipoglicemiantes/sangue , Hipoglicemiantes/química , Masculino , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Pirrolidinas/sangue , Pirrolidinas/química , Ratos , Ratos Sprague-Dawley , Solubilidade , Estreptozocina , Relação Estrutura-Atividade , Termodinâmica
18.
Talanta ; 210: 120612, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987202

RESUMO

A new strategy endowing probe with large Stokes shift, high quantum yield and red emission was developed by incorporating tetrahydroquinoxaline unit and five-membered pyrrolidine ring on fluorophore. As demonstrated, a novel probe was rationally designed and synthesized for sensitive monitor of cellular cysteine (Cys) and endogenous aminoacylase with large Stokes shift and high quantum yield.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Imagem Óptica , Pirrolidinas/química , Teoria Quântica , Quinoxalinas/química , Animais , Células Cultivadas , Corantes Fluorescentes/síntese química , Camundongos , Estrutura Molecular , Pirrolidinas/síntese química , Quinoxalinas/síntese química , Células RAW 264.7
19.
Int J Pharm ; 577: 119065, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31988034

RESUMO

In the pharmaceutical industry, polymers are used as excipients for formulating poorly water-soluble active pharmaceutical ingredients (APIs) in so-called "amorphous solid dispersions" (ASDs). ASDs can be produced via solvent-based processes, where API and polymer are both dissolved in a solvent, followed by a solvent evaporation step (e.g. spray drying). Aiming at a homogeneous API/polymer formulation, phase separation of the components (API, polymer, solvent) during solvent evaporation must be avoided. The latter is often determined by the phase behavior of polymer/solvent mixtures used for ASD processing. Therefore, this work investigates the polymer-solvent interactions in these mixtures. Suitable polymer/solvent combinations investigated in this work comprise the pharmaceutically relevant polymers poly(vinylpyrrolidone) (PVP), poly(vinylpyrrolidone-co-vinyl acetate) (PVPVA64), and hydroxyppropyl methylcellulose acetate succinate 126G (HPMCAS) as well as the solvents acetone, dichloromethane (DCM), ethanol, ethyl acetate, methanol, and water. Based on vapor-sorption experiments demixing of solvents and polymers were predicted using the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT). These were found to be correct for all investigated solvent/polymer mixtures. Acetone, DCM, ethanol, methanol, and water were found to be completely miscible with PVPVA64. DCM, ethanol, methanol, and water were found to be completely miscible with PVP K90, while none of the investigated solvents was appropriate for avoiding immiscibility with HPMCAS. In addition, the impact of temperature, polymer molecular weight, and solvent-mixture composition on miscibility was successfully predicted using PC-SAFT. Thus, the proposed methodology allows identifying suitable solvents or solvent mixtures relevant for solvent-based preparations of pharmaceutical ASD formulations with low experimental effort.


Assuntos
Química Farmacêutica , Excipientes/química , Polímeros/química , Solventes/química , Metilcelulose/análogos & derivados , Metilcelulose/química , Peso Molecular , Transição de Fase , Povidona/química , Pirrolidinas/química , Temperatura , Compostos de Vinila/química
20.
J Anal Toxicol ; 44(2): 163-172, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-31424078

RESUMO

A method was developed for quantitative estimation of illicit psychostimulants in blood, with an emphasis on new psychoactive substances, based on gas chromatography nitrogen chemiluminescence detection coupled with atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry (GC-NCD-APCI-QTOFMS). Quantitative estimation relied on the NCD's N-equimolar response to nitrogen, using amphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and methylenedioxypyrovalerone as external calibrators for prim-, sec- and tert- amines, respectively. After spiking with 38 stimulants at 3 concentration levels, the donor blood samples were submitted to liquid-liquid extraction at a basic pH followed by acylation with trifluoroacetic anhydride. All but 3 psychostimulants could be analyzed with a limit of quantification (LOQ) of 0.05 mg/L. At LOQ, the coefficient of variation (CV) values for between-day accuracy was 62.3-143.3% (mean, 93.5%; median, 88.5%) and precision 6.6-22.4% (mean, 15.8%; median, 16.1%). In addition, 11 post-mortem blood samples, containing 0.08-2.4 mg/L of amphetamine (n = 5), methamphetamine (n = 4) or MDMA (n = 4), were analyzed by the GC-NCD-APCI-QTOFMS method, and the results were compared with an established electron ionization GC-MS method with appropriate calibration. The agreement between the 2 methods was 62.5-117.3%. Regarding identification, the APCI source permitted detection of the intact precursor ion, or the respective acylation product, for all of the measured compounds. The GC-NCD-APCI-QTOFMS method developed here enables instant quantitative estimation of illicit psychostimulants in blood at reasonable accuracy, without the necessity of possessing the true reference standards for each analyte.


Assuntos
Estimulantes do Sistema Nervoso Central/análise , Drogas Ilícitas/análise , Anfetamina/análise , Anfetamina/química , Benzodioxóis/análise , Benzodioxóis/química , Calibragem , Estimulantes do Sistema Nervoso Central/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Drogas Ilícitas/química , Luminescência , Metanfetamina/análise , Metanfetamina/química , N-Metil-3,4-Metilenodioxianfetamina/análise , N-Metil-3,4-Metilenodioxianfetamina/química , Nitrogênio , Pirrolidinas/análise , Pirrolidinas/química , Detecção do Abuso de Substâncias
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