scholarly journals Organoselenium mild electrophiles in the inhibition of Mpro and SARSCoV-2 replication

2020 ◽  
Author(s):  
Luca Sancineto ◽  
Francesca Mangiavacchi ◽  
Agnieszka Dąbrowska ◽  
Agata Pacuła ◽  
Magdalena Obieziurska-Fabisiak ◽  
...  
Keyword(s):  
Cytopathic Effect ◽  
Selenium Atom ◽  
Inhibition Activity ◽  
Exchange Processes ◽  
Main Protease ◽  
In Vitro Inhibition ◽  
Complex Scenario ◽  
Detoxification Process

New Ebselen-like derivatives resulted to be very strong in vitro inhibitors of SARS-CoV-2 main protease. We demonstrated that this activity mainly depends on the electrophilicity of the selenium atom that is considerably higher in the N-substituted 1,2- benzoselenazol-3(2H)-ones respect to the corresponding diselenides allowing it to be rapidly attached by free thiols affording sulfur-selenium intermediates that are further subjected to thiol exchange processes. This data paints a very complex scenario that requires us to consider Ebselen and Ebselen-like derivatives as potential electrophilic substrates for the several other free thiols present in the cell beside the target free cysteine. The sulfur selenium intermediates are milder electrophiles that could be theoretically implicated in both the detoxification process as well as in the final enzymatic inhibition. We here demonstrated that the in vitro inhibition activity is not fully reproduced in the prevention of viral replication in the cell-based assay. This indicates that the structure of the substituents introduced in the Ebselen scaffold is a crucial factor to control the reactivity of the selenated molecule in the network of thiol exchanges, as well as for molecular recognition of the targeted enzymatic cysteine. For this reason, an in-depth investigation is strongly desirable to better understand how to increase the activity and the selectivity of Ebselen derivatives overcoming the issues of the apparent PAINS-like role of Ebselen. Furthermore, besides the antiviral activity, thee selected compounds also showed a different ability to reduce the virus-induced cytopathic effect, indicating that other mechanisms could be implicated. One may consider here the well-known cytoprotective antioxidant activity of Ebselen and its derivatives.<p></p>

Organoselenium mild electrophiles in the inhibition of Mpro and SARSCoV-2 replication

2020 ◽  
Author(s):  
Luca Sancineto ◽  
Francesca Mangiavacchi ◽  
Agnieszka Dąbrowska ◽  
Agata Pacuła ◽  
Magdalena Obieziurska-Fabisiak ◽  
...  
Keyword(s):  
Cytopathic Effect ◽  
Selenium Atom ◽  
Inhibition Activity ◽  
Exchange Processes ◽  
Main Protease ◽  
In Vitro Inhibition ◽  
Complex Scenario ◽  
Detoxification Process

New Ebselen-like derivatives resulted to be very strong in vitro inhibitors of SARS-CoV-2 main protease. We demonstrated that this activity mainly depends on the electrophilicity of the selenium atom that is considerably higher in the N-substituted 1,2- benzoselenazol-3(2H)-ones respect to the corresponding diselenides allowing it to be rapidly attached by free thiols affording sulfur-selenium intermediates that are further subjected to thiol exchange processes. This data paints a very complex scenario that requires us to consider Ebselen and Ebselen-like derivatives as potential electrophilic substrates for the several other free thiols present in the cell beside the target free cysteine. The sulfur selenium intermediates are milder electrophiles that could be theoretically implicated in both the detoxification process as well as in the final enzymatic inhibition. We here demonstrated that the in vitro inhibition activity is not fully reproduced in the prevention of viral replication in the cell-based assay. This indicates that the structure of the substituents introduced in the Ebselen scaffold is a crucial factor to control the reactivity of the selenated molecule in the network of thiol exchanges, as well as for molecular recognition of the targeted enzymatic cysteine. For this reason, an in-depth investigation is strongly desirable to better understand how to increase the activity and the selectivity of Ebselen derivatives overcoming the issues of the apparent PAINS-like role of Ebselen. Furthermore, besides the antiviral activity, thee selected compounds also showed a different ability to reduce the virus-induced cytopathic effect, indicating that other mechanisms could be implicated. One may consider here the well-known cytoprotective antioxidant activity of Ebselen and its derivatives.<p></p>

scholarly journals Flavonols and dihydroflavonols inhibit the main protease activity of SARS-CoV-2 and the replication of human coronavirus 229E

2021 ◽  
Author(s):  
Yue Zhu ◽  
Frank Scholle ◽  
Samantha C. Kisthardt ◽  
Deyu Xie
Keyword(s):  
Docking Simulation ◽  
Binding Pocket ◽  
Developed Countries ◽  
Host Cells ◽  
Human Coronavirus ◽  
Main Protease ◽  
Ic50 Values ◽  
In Vitro Inhibition ◽  
Human Coronavirus 229E

Since December 2019, the deadly novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the current COVID-19 pandemic. To date, vaccines are available in the developed countries to prevent the infection of this virus, however, medicines are necessary to help control COVID-19. Human coronavirus 229E (HCoV-229E) causes the common cold. The main protease (Mpro) is an essential enzyme required for the multiplication of these two viruses in the host cells, and thus is an appropriate candidate to screen potential medicinal compounds. Flavonols and dihydroflavonols are two groups of plant flavonoids. In this study, we report docking simulation with two Mpro enzymes and five flavonols and three dihydroflavonols, in vitro inhibition of the SARS-CoV-2 Mpro, and in vitro inhibition of the HCoV 229E replication. The docking simulation results predicted that (+)-dihydrokaempferol, (+)-dihydroquercetin, (+)-dihydromyricetin, kaempferol, quercetin, myricentin, isoquercetin, and rutin could bind to at least two subsites (S1, S1', S2, and S4) in the binding pocket and inhibit the activity of SARS-CoV-2 Mpro. Their affinity scores ranged from -8.8 to -7.4. Likewise, these compounds were predicted to bind and inhibit the HCoV-229E Mpro activity with affinity scores ranging from -7.1 to -7.8. In vitro inhibition assays showed that seven available compounds effectively inhibited the SARS-CoV-2 Mpro activity and their IC50 values ranged from 0.125 to 12.9 uM. Five compounds inhibited the replication of HCoV-229E in Huh-7 cells. These findings indicate that these antioxidative flavonols and dihydroflavonols are promising candidates for curbing the two viruses.

scholarly journals Discovery of Novel Imidazopyridine GSK-3β Inhibitors Supported by Computational Approaches

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2163
Author(s):  
Rosa Buonfiglio ◽  
Federica Prati ◽  
Martina Bischetti ◽  
Claudia Cavarischia ◽  
Guido Furlotti ◽  
...  
Keyword(s):  
Fine Tuning ◽  
Inhibition Activity ◽  
Design Synthesis ◽  
In Vitro Characterization ◽  
Gsk 3Β ◽  
In Silico Models ◽  
Acidic Hydrogen

The interest of research groups and pharmaceutical companies to discover novel GSK-3β inhibitors has increased over the years considering the involvement of this enzyme in many pathophysiological processes and diseases. Along this line, we recently reported on 1H-indazole-3-carboxamide (INDZ) derivatives 1–6, showing good GSK-3β inhibition activity. However, they suffered from generally poor central nervous system (CNS) permeability. Here, we describe the design, synthesis, and in vitro characterization of novel imidazo[1,5-a]pyridine-1-carboxamide (IMID 1) and imidazo[1,5-a]pyridine-3-carboxamide (IMID 2) compounds (7–18) to overcome such liability. In detail, structure-based approaches and fine-tuning of physicochemical properties guided the design of derivatives 7–18 resulting in ameliorated absorption, distribution, metabolism, and excretion (ADME) properties. A crystal structure of 16 in complex with GSK-3β enzyme (PDB entry 6Y9S) confirmed the in silico models. Despite the nanomolar inhibition activity, the new core compounds showed a reduction in potency with respect to INDZ derivatives 1–6. In this context, Molecular Dynamics (MD) and Quantum Mechanics (QM) based approaches along with NMR investigation helped to rationalize the observed structure activity relationship (SAR). With these findings, the key role of the acidic hydrogen of the central core for a tight interaction within the ATP pocket of the enzyme reflecting in good GSK-3β affinity was demonstrated.

scholarly journals Seleno-Functionalization of Quercetin Improves the Non-Covalent Inhibition of Mpro and Its Antiviral Activity in Cells against SARS-CoV-2

2021 ◽  
Vol 22 (13) ◽  
pp. 7048
Author(s):  
Francesca Mangiavacchi ◽  
Pawel Botwina ◽  
Elena Menichetti ◽  
Luana Bagnoli ◽  
Ornelio Rosati ◽  
...  
Keyword(s):  
Selenium Atom ◽  
Quercetin Derivatives ◽  
Main Protease ◽  
Infected Cells ◽  
Flavonoid Quercetin ◽  
Flavone Derivatives ◽  
Toxic Concentrations ◽  
First Time

The development of new antiviral drugs against SARS-CoV-2 is a valuable long-term strategy to protect the global population from the COVID-19 pandemic complementary to the vaccination. Considering this, the viral main protease (Mpro) is among the most promising molecular targets in light of its importance during the viral replication cycle. The natural flavonoid quercetin 1 has been recently reported to be a potent Mpro inhibitor in vitro, and we explored the effect produced by the introduction of organoselenium functionalities in this scaffold. In particular, we report here a new synthetic method to prepare previously inaccessible C-8 seleno-quercetin derivatives. By screening a small library of flavonols and flavone derivatives, we observed that some compounds inhibit the protease activity in vitro. For the first time, we demonstrate that quercetin (1) and 8-(p-tolylselenyl)quercetin (2d) block SARS-CoV-2 replication in infected cells at non-toxic concentrations, with an IC50 of 192 μM and 8 μM, respectively. Based on docking experiments driven by experimental evidence, we propose a non-covalent mechanism for Mpro inhibition in which a hydrogen bond between the selenium atom and Gln189 residue in the catalytic pocket could explain the higher Mpro activity of 2d and, as a result, its better antiviral profile.

scholarly journals Synthesis and Inhibition Activity Study of Triazinyl-Substituted Amino(alkyl)-benzenesulfonamide Conjugates with Polar and Hydrophobic Amino Acids as Inhibitors of Human Carbonic Anhydrases I, II, IV, IX, and XII

2021 ◽  
Vol 22 (20) ◽  
pp. 11283
Author(s):  
Mária Bodnár Mikulová ◽  
Dáša Kružlicová ◽  
Daniel Pecher ◽  
Andrea Petreni ◽  
Claudiu T. Supuran ◽  
...  
Keyword(s):  
Amino Acids ◽  
Side Chain ◽  
Carbonic Anhydrases ◽  
Inhibition Activity ◽  
Short Reaction Time ◽  
High Affinity ◽  
Hydrophobic Amino Acids ◽  
In Vitro Inhibition ◽  
Inhibition Studies

Primary sulfonamide derivatives with various heterocycles represent the most widespread group of potential human carbonic anhydrase (hCA) inhibitors with high affinity and selectivity towards specific isozymes from the hCA family. In this work, new 4-aminomethyl- and aminoethyl-benzenesulfonamide derivatives with 1,3,5-triazine disubstituted with a pair of identical amino acids, possessing a polar (Ser, Thr, Asn, Gln) and non-polar (Ala, Tyr, Trp) side chain, have been synthesized. The optimized synthetic, purification, and isolation procedures provided several pronounced benefits such as a short reaction time (in sodium bicarbonate aqueous medium), satisfactory yields for the majority of new products (20.6–91.8%, average 60.4%), an effective, well defined semi-preparative RP-C18 liquid chromatography (LC) isolation of desired products with a high purity (>97%), as well as preservation of green chemistry principles. These newly synthesized conjugates, plus their 4-aminobenzenesulfonamide analogues prepared previously, have been investigated in in vitro inhibition studies towards hCA I, II, IV and tumor-associated isozymes IX and XII. The experimental results revealed the strongest inhibition of hCA XII with low nanomolar inhibitory constants (Kis) for the derivatives with amino acids possessing non-polar side chains (7.5–9.6 nM). Various derivatives were also promising for some other isozymes.

scholarly journals The effect of isoferritins on granulopoiesis

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 436-443 ◽  
Author(s):  
G Sala ◽  
M Worwood ◽  
A Jacobs
Keyword(s):  
Monoclonal Antibody ◽  
Colony Formation ◽  
Colony Growth ◽  
Conditioned Media ◽  
Regulatory Role ◽  
Consistent Effect ◽  
Cell Extracts ◽  
In Vitro Inhibition

Abstract The evidence for a regulatory role of acidic isoferritins on hemopoiesis is not entirely consistent with our knowledge of ferritin biochemistry, and no clear picture of this phenomeonon has emerged. In the present study, we have been unable to confirm a consistent effect of purified heart (acidic), spleen (basic), or serum (glycosylated) isoferritins on CFU-GM colony formation in vitro. Inhibition of colony formation by cell extracts or conditioned media does not relate to the presence of acidic isoferritins, nor is this effect neutralized by a monoclonal antibody to acidic isoferritins. The composition of ferritin preparations previously described as inhibitory to CFU-GM colony growth could not be confirmed, and they were not found to be predominantly acidic in nature. Our data do not support a role for acidic isoferritins as inhibitors of granulopoiesis.

scholarly journals The Neurovirulence of the DA and GDVII Strains of Theiler’s Virus Correlates with Their Ability To Infect Cultured Neurons

1998 ◽  
Vol 72 (9) ◽  
pp. 7213-7220 ◽  
Author(s):  
Nadine Jarousse ◽  
Sylvie Syan ◽  
Cécile Martinat ◽  
Michel Brahic
Keyword(s):  
Viral Entry ◽  
Cytopathic Effect ◽  
Demyelinating Disease ◽  
Cultured Neurons ◽  
Theiler's Virus ◽  
Recombinant Viruses ◽  
Encephalomyelitis Virus ◽  
Highly Virulent

ABSTRACT The strains of Theiler’s murine encephalomyelitis virus, a picornavirus, are divided into two groups according to their neurovirulence after intracerebral inoculation. The highly virulent GDVII strain causes an acute, fatal encephalomyelitis, whereas the DA strain causes a mild encephalomyelitis followed by a chronic inflammatory demyelinating disease associated with viral persistence. Studies with recombinant viruses showed that the capsid plays the major role in determining these phenotypes. However, the molecular basis for the effect of the capsid on neurovirulence is still unknown. In this paper, we describe a large difference in the patterns of infection of primary neuron cultures by the GDVII and DA strains. Close to 90% of the neurons were infected 12 h after inoculation with the GDVII strain, and the cytopathic effect was complete 24 h postinoculation. In contrast, with the DA strain, viral antigens were not detected in neurons until 24 h postinoculation. Infected neurons accounted for only 2% of the total number of neurons, even 6 days after inoculation. No cytopathic effect was visible, and the cultures could be kept for the same length of time as the noninfected controls. Because the neurovirulence of the GDVII strain has been mapped to the capsid, we examined the role of the capsid in this difference of phenotype. We showed, using recombinant viruses, that the capsid was indeed responsible for the pattern of infection observed in vitro, most likely through its role in viral entry. Thus, the levels of neurovirulence of the GDVII and DA strains correlate with their abilities to infect cultured neurons, and this ability is controlled by the capsid.

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