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1.
Sci Rep ; 12(1): 3316, 2022 02 28.
Article in English | MEDLINE | ID: covidwho-1713215

ABSTRACT

The new coronavirus, SARS-CoV-2, caused the COVID-19 pandemic, characterized by its high rate of contamination, propagation capacity, and lethality rate. In this work, we approach the use of phthalocyanines as an inhibitor of SARS-CoV-2, as they present several interactive properties of the phthalocyanines (Pc) of Cobalt (CoPc), Copper (CuPc) and without a metal group (NoPc) can interact with SARS-CoV-2, showing potential be used as filtering by adsorption on paints on walls, masks, clothes, and air conditioning filters. Molecular modeling techniques through Molecular Docking and Molecular Dynamics were used, where the target was the external structures of the virus, but specifically the envelope protein, main protease, and Spike glycoprotein proteases. Using the g_MM-GBSA module and with it, the molecular docking studies show that the ligands have interaction characteristics capable of adsorbing the structures. Molecular dynamics provided information on the root-mean-square deviation of the atomic positions provided values between 1 and 2.5. The generalized Born implicit solvation model, Gibbs free energy, and solvent accessible surface area approach were used. Among the results obtained through molecular dynamics, it was noticed that interactions occur since Pc could bind to residues of the active site of macromolecules, demonstrating good interactions; in particular with CoPc. Molecular couplings and free energy showed that S-gly active site residues interacted strongly with phthalocyanines with values ​​of - 182.443 kJ/mol (CoPc), 158.954 kJ/mol (CuPc), and - 129.963 kJ/mol (NoPc). The interactions of Pc's with SARS-CoV-2 may predict some promising candidates for antagonists to the virus, which if confirmed through experimental approaches, may contribute to resolving the global crisis of the COVID-19 pandemic.


Subject(s)
COVID-19 , Cobalt/chemistry , Coordination Complexes/chemistry , Copper/chemistry , Isoindoles/chemistry , Molecular Docking Simulation , Molecular Dynamics Simulation , SARS-CoV-2/chemistry , Viral Proteins/chemistry , Humans
2.
Nucleic Acids Res ; 50(3): 1484-1500, 2022 02 22.
Article in English | MEDLINE | ID: covidwho-1624985

ABSTRACT

The SARS-CoV-2 coronavirus is the causal agent of the current global pandemic. SARS-CoV-2 belongs to an order, Nidovirales, with very large RNA genomes. It is proposed that the fidelity of coronavirus (CoV) genome replication is aided by an RNA nuclease complex, comprising the non-structural proteins 14 and 10 (nsp14-nsp10), an attractive target for antiviral inhibition. Our results validate reports that the SARS-CoV-2 nsp14-nsp10 complex has RNase activity. Detailed functional characterization reveals nsp14-nsp10 is a versatile nuclease capable of digesting a wide variety of RNA structures, including those with a blocked 3'-terminus. Consistent with a role in maintaining viral genome integrity during replication, we find that nsp14-nsp10 activity is enhanced by the viral RNA-dependent RNA polymerase complex (RdRp) consisting of nsp12-nsp7-nsp8 (nsp12-7-8) and demonstrate that this stimulation is mediated by nsp8. We propose that the role of nsp14-nsp10 in maintaining replication fidelity goes beyond classical proofreading by purging the nascent replicating RNA strand of a range of potentially replication-terminating aberrations. Using our developed assays, we identify drug and drug-like molecules that inhibit nsp14-nsp10, including the known SARS-CoV-2 major protease (Mpro) inhibitor ebselen and the HIV integrase inhibitor raltegravir, revealing the potential for multifunctional inhibitors in COVID-19 treatment.


Subject(s)
Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , Exoribonucleases/metabolism , Genome, Viral/genetics , Genomic Instability , SARS-CoV-2/enzymology , SARS-CoV-2/genetics , Viral Nonstructural Proteins/metabolism , Viral Regulatory and Accessory Proteins/metabolism , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Exoribonucleases/antagonists & inhibitors , Genome, Viral/drug effects , Genomic Instability/drug effects , Genomic Instability/genetics , HIV Integrase Inhibitors/pharmacology , Isoindoles/pharmacology , Multienzyme Complexes/antagonists & inhibitors , Multienzyme Complexes/metabolism , Organoselenium Compounds/pharmacology , RNA, Viral/biosynthesis , RNA, Viral/genetics , Raltegravir Potassium/pharmacology , SARS-CoV-2/drug effects , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Regulatory and Accessory Proteins/antagonists & inhibitors , Virus Replication/drug effects , Virus Replication/genetics
3.
Chem Biodivers ; 18(11): e2100674, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1615945

ABSTRACT

Chemical investigation on a Streptomyces sp. strain MS180069 isolated from a sediment sample collected from the South China Sea, yielded the new benzo[f]isoindole-dione alkaloid, bhimamycin J (1). The structure was determined by extensive spectroscopic analysis, including HRMS, 1D, 2D NMR, and X-ray diffraction techniques. A molecular docking study revealed 1 as a new molecular motif that binds with human angiotensin converting enzyme2 (ACE2), recently described as the cell surface receptor responsible for uptake of 2019-CoV-2. Using enzyme assays we confirm that 1 inhibits human ACE2 79.7 % at 25 µg/mL.


Subject(s)
Alkaloids/chemistry , Geologic Sediments/microbiology , Isoindoles/chemistry , Streptomyces/chemistry , Alkaloids/metabolism , Alkaloids/pharmacology , Alkaloids/therapeutic use , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/metabolism , Binding Sites , COVID-19/drug therapy , COVID-19/virology , Fungi/drug effects , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Humans , Isoindoles/isolation & purification , Isoindoles/metabolism , Isoindoles/pharmacology , Magnetic Resonance Spectroscopy , Molecular Conformation , Molecular Docking Simulation , SARS-CoV-2/isolation & purification , Streptomyces/isolation & purification , Streptomyces/metabolism
4.
ChemMedChem ; 17(4): e202100582, 2022 02 16.
Article in English | MEDLINE | ID: covidwho-1540073

ABSTRACT

The reactive organoselenium compound ebselen is being investigated for treatment of coronavirus disease 2019 (COVID-19) and other diseases. We report structure-activity studies on sulfur analogues of ebselen with the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro ), employing turnover and protein-observed mass spectrometry-based assays. The results reveal scope for optimisation of ebselen/ebselen derivative- mediated inhibition of Mpro , particularly with respect to improved selectivity.


Subject(s)
Coronavirus 3C Proteases/antagonists & inhibitors , Isoindoles/pharmacology , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/enzymology , COVID-19/virology , Humans , Isoindoles/chemistry , Organoselenium Compounds/chemistry , Protease Inhibitors/chemistry , Structure-Activity Relationship
5.
Bioorg Chem ; 117: 105455, 2021 12.
Article in English | MEDLINE | ID: covidwho-1487613

ABSTRACT

The main protease (Mpro or 3CLpro) of SARS-CoV-2 virus is a cysteine enzyme critical for viral replication and transcription, thus indicating a potential target for antiviral therapy. A recent repurposing effort has identified ebselen, a multifunctional drug candidate as an inhibitor of Mpro. Our docking of ebselen to the binding pocket of Mpro crystal structure suggests a noncovalent interaction for improvement of potency, antiviral activity and selectivity. To test this hypothesis, we designed and synthesized ebselen derivatives aimed at enhancing their non-covalent bonds within Mpro. The inhibition of Mpro by ebselen derivatives (0.3 µM) was screened in both HPLC and FRET assays. Nine ebselen derivatives (EBs) exhibited stronger inhibitory effect on Mpro with IC50 of 0.07-0.38 µM. Further evaluation of three derivatives showed that EB2-7 exhibited the most potent inhibition of SARS-CoV-2 viral replication with an IC50 value of 4.08 µM in HPAepiC cells, as compared to the prototype ebselen at 24.61 µM. Mechanistically, EB2-7 functions as a noncovalent Mpro inhibitor in LC-MS/MS assay. Taken together, our identification of ebselen derivatives with improved antiviral activity may lead to developmental potential for treatment of COVID-19 and SARS-CoV-2 infection.


Subject(s)
Antiviral Agents/chemistry , Coronavirus 3C Proteases/chemistry , Isoindoles/chemistry , Organoselenium Compounds/chemistry , SARS-CoV-2/enzymology , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Binding Sites , COVID-19/drug therapy , COVID-19/virology , Catalytic Domain , Cell Line , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Coronavirus 3C Proteases/metabolism , Drug Design , Fluorescence Resonance Energy Transfer , Humans , Isoindoles/metabolism , Isoindoles/pharmacology , Isoindoles/therapeutic use , Molecular Docking Simulation , Organoselenium Compounds/metabolism , Organoselenium Compounds/pharmacology , Organoselenium Compounds/therapeutic use , SARS-CoV-2/isolation & purification , Structure-Activity Relationship , Tandem Mass Spectrometry
6.
Sci Rep ; 11(1): 19937, 2021 10 07.
Article in English | MEDLINE | ID: covidwho-1462022

ABSTRACT

The risk of contamination and dissemination by SARS-CoV-2 has a strong link with nasal, oral and pharyngeal cavities. Recently, our research group observed the promising performance of an anionic phthalocyanine derivative (APD) used in a mouthwash protocol without photoexcitation; this protocol improved the general clinical condition of patients infected with SARS-CoV-2. The present two-arm study evaluated in vitro the antiviral activity and cytotoxicity of APD. Additionally, a triple-blind randomized controlled trial was conducted with 41 hospitalized patients who tested positive for COVID-19. All the included patients received World Health Organization standard care hospital treatment (non-intensive care) plus active mouthwash (experimental group AM/n = 20) or nonactive mouthwash (control group NAM/n = 21). The adjunct mouthwash intervention protocol used in both groups consisted one-minute gargling/rinsing / 5 times/day until hospital discharge. Groups were compared considering age, number of comorbidities, duration of symptoms prior admission and length of hospital stay (LOS). The associations between group and sex, age range, presence of comorbidities, admission to Intensive care unit (ICU) and death were also evaluated. The in vitro evaluation demonstrated that APD compound was highly effective for reduction of SARS-CoV-2 viral load in the 1.0 mg/mL (99.96%) to 0.125 mg/mL (92.65%) range without causing cytotoxicity. Regarding the clinical trial, the median LOS of the AM group was significantly shortened (4 days) compared with that of the NAM group (7 days) (p = 0.0314). Additionally, gargling/rinsing with APD was very helpful in reducing the severity of symptoms (no ICU care was needed) compared to not gargling/rinsing with APD (28.6% of the patients in the NAM group needed ICU care, and 50% of this ICU subgroup passed way, p = 0.0207). This study indicated that the mechanical action of the protocol involving mouthwash containing a compound with antiviral effects against SARS-CoV-2 may reduce the symptoms of the patients and the spread of infection. The use of APD in a mouthwash as an adjuvant the hospital COVID-19 treatment presented no contraindication and reduced the hospital stay period.Trial registration: The clinical study was registered at REBEC-Brazilian Clinical Trial Register (RBR-58ftdj).


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Isoindoles/therapeutic use , Mouthwashes/therapeutic use , Adult , Aged , Animals , Antiviral Agents/chemistry , Brazil/epidemiology , COVID-19/epidemiology , Chlorocebus aethiops , Female , Humans , Isoindoles/chemistry , Length of Stay , Male , Middle Aged , Mouthwashes/chemistry , SARS-CoV-2/drug effects , Vero Cells
7.
Int J Mol Sci ; 22(18)2021 Sep 10.
Article in English | MEDLINE | ID: covidwho-1409705

ABSTRACT

The inhibition mechanism of the main protease (Mpro) of SARS-CoV-2 by ebselen (EBS) and its analog with a hydroxyl group at position 2 of the benzisoselenazol-3(2H)-one ring (EBS-OH) was studied by using a density functional level of theory. Preliminary molecular dynamics simulations on the apo form of Mpro were performed taking into account both the hydrogen donor and acceptor natures of the Nδ and Nε of His41, a member of the catalytic dyad. The potential energy surfaces for the formation of the Se-S covalent bond mediated by EBS and EBS-OH on Mpro are discussed in detail. The EBS-OH shows a distinctive behavior with respect to EBS in the formation of the noncovalent complex. Due to the presence of canonical H-bonds and noncanonical ones involving less electronegative atoms, such as sulfur and selenium, the influence on the energy barriers and reaction energy of the Minnesota hybrid meta-GGA functionals M06, M06-2X and M08HX, and the more recent range-separated hybrid functional wB97X were also considered. The knowledge of the inhibition mechanism of Mpro by the small protease inhibitors EBS or EBS-OH can enlarge the possibilities for designing more potent and selective inhibitor-based drugs to be used in combination with other antiviral therapies.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus 3C Proteases/antagonists & inhibitors , Isoindoles/pharmacology , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , Antiviral Agents/therapeutic use , Binding Sites/drug effects , COVID-19/virology , Catalytic Domain/drug effects , Coronavirus 3C Proteases/metabolism , Drug Design , Humans , Isoindoles/chemistry , Isoindoles/therapeutic use , Molecular Docking Simulation , Molecular Dynamics Simulation , Organoselenium Compounds/chemistry , Organoselenium Compounds/therapeutic use , Protease Inhibitors/chemistry , Protease Inhibitors/therapeutic use , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism
8.
Nat Commun ; 12(1): 3061, 2021 05 24.
Article in English | MEDLINE | ID: covidwho-1387342

ABSTRACT

The SARS-CoV-2 pandemic has triggered global efforts to develop therapeutics. The main protease of SARS-CoV-2 (Mpro), critical for viral replication, is a key target for therapeutic development. An organoselenium drug called ebselen has been demonstrated to have potent Mpro inhibition and antiviral activity. We have examined the binding modes of ebselen and its derivative in Mpro via high resolution co-crystallography and investigated their chemical reactivity via mass spectrometry. Stronger Mpro inhibition than ebselen and potent ability to rescue infected cells were observed for a number of derivatives. A free selenium atom bound with cysteine of catalytic dyad has been revealed in crystallographic structures of Mpro with ebselen and MR6-31-2 suggesting hydrolysis of the enzyme bound organoselenium covalent adduct and formation of a phenolic by-product, confirmed by mass spectrometry. The target engagement with selenation mechanism of inhibition suggests wider therapeutic applications of these compounds against SARS-CoV-2 and other zoonotic beta-corona viruses.


Subject(s)
Azoles/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Organoselenium Compounds/pharmacology , SARS-CoV-2/enzymology , Antiviral Agents/pharmacology , Azoles/chemistry , Catalytic Domain , Coronavirus 3C Proteases/metabolism , Crystallography, X-Ray , Cysteine/chemistry , Hydrolysis , Isoindoles , Models, Molecular , Organoselenium Compounds/chemistry , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , Reference Standards , SARS-CoV-2/drug effects , Salicylanilides/chemistry , Salicylanilides/pharmacology , Selenium/metabolism
9.
Arch Toxicol ; 95(4): 1179-1226, 2021 04.
Article in English | MEDLINE | ID: covidwho-1384375

ABSTRACT

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.


Subject(s)
Organoselenium Compounds/pharmacology , Organoselenium Compounds/toxicity , Amino Acids/chemistry , Animals , Azoles , Humans , Isoindoles , Molecular Structure , Selenium/chemistry , Selenium/physiology , Selenoproteins/chemistry , Sulfhydryl Compounds/chemistry
10.
Pharmacol Res Perspect ; 9(1): e00691, 2021 02.
Article in English | MEDLINE | ID: covidwho-1384293

ABSTRACT

Coronaviruses represent global health threat. In this century, they have already caused two epidemics and one serious pandemic. Although, at present, there are no approved drugs and therapies for the treatment and prevention of human coronaviruses, several agents, FDA-approved, and preclinical, have shown in vitro and/or in vivo antiviral activity. An in-depth analysis of the current situation leads to the identification of several potential drugs that could have an impact on the fight against coronaviruses infections. In this review, we discuss the virology of human coronaviruses highlighting the main biological targets and summarize the current state-of-the-art of possible therapeutic options to inhibit coronaviruses infections. We mostly focus on FDA-approved and preclinical drugs targeting viral conserved elements.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Coronavirus Infections/metabolism , Coronavirus/metabolism , Dipeptidyl Peptidase 4/metabolism , Severe Acute Respiratory Syndrome/metabolism , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Angiotensin-Converting Enzyme Inhibitors/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/metabolism , Antiviral Agents/administration & dosage , Antiviral Agents/metabolism , Azoles/administration & dosage , Azoles/metabolism , COVID-19/drug therapy , Coronavirus/drug effects , Coronavirus Infections/drug therapy , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/metabolism , Humans , Isoindoles , Naphthoquinones/administration & dosage , Naphthoquinones/metabolism , Organoselenium Compounds/administration & dosage , Organoselenium Compounds/metabolism , Severe Acute Respiratory Syndrome/drug therapy
13.
Environ Sci Technol ; 54(18): 11271-11281, 2020 09 15.
Article in English | MEDLINE | ID: covidwho-1373338

ABSTRACT

Ebselen (EBS), 2-phenyl-1,2-benzisoselenazol-3(2H)-one, is an organoselenium pharmaceutical with antioxidant and anti-inflammatory properties. Furthermore, EBS is an excellent scavenger of reactive oxygen species. This property complicates conventional protocols for sensitizing and quenching reactive species because of potential generation of active intermediates that quickly react with EBS. In this study, the photochemical reactivity of EBS was investigated in the presence of (1) 1O2 and •OH sensitizers [rose Bengal (RB), perinaphthanone, and H2O2] and (2) reactive species scavenging and quenching agents (sorbic acid, isopropanol, sodium azide, and tert-butanol) that are commonly employed to study photodegradation mechanisms and kinetics. The carbon analogue of EBS, namely, 2-phenyl-3H-isoindol-1-one, was included as a reference compound to confirm the impact of the selenium atom on EBS photochemical reactivity. EBS does not undergo acid dissociation, but pH-dependent kinetics were observed in RB-sensitized solutions, suggesting EBS reaction with active intermediates (3RB2-*, O2•-, and H2O2) that are not kinetically relevant for other compounds. In addition, the observed rate constant of EBS increased in the presence of sorbic acid, isopropanol, and sodium azide. These findings suggest that conventional reactive species sensitizers, scavengers, and quenchers need to be carefully applied to highly reactive organoselenium compounds to account for reactions that are typically slow for other organic contaminants.


Subject(s)
Hydrogen Peroxide , Organoselenium Compounds , Azoles , Isoindoles , Photolysis
14.
Viruses ; 13(8)2021 08 15.
Article in English | MEDLINE | ID: covidwho-1355053

ABSTRACT

We compared the electrostatic properties of the spike proteins (S-proteins) of three coronaviruses, SARS-CoV, MERS-CoV, and SARS-CoV-2, and their interactions with photosensitizers (PSs), octacationic octakis(cholinyl)zinc phthalocyanine (Zn-PcChol8+) and monocationic methylene blue (MB). We found a major common PS binding site at the connection of the S-protein stalk and head. The molecules of Zn-PcChol8+ and MB also form electrostatic encounter complexes with large area of negative electrostatic potential at the head of the S-protein of SARS-CoV-2, between fusion protein and heptad repeat 1 domain. The top of the SARS-CoV spike head demonstrates a notable area of electrostatic contacts with Zn-PcChol8+ and MB that corresponds to the N-terminal domain. The S-protein protomers of SARS-CoV-2 in "open" and "closed" conformations demonstrate different ability to attract PS molecules. In contrast with Zn-PcChol8+, MB possesses the ability to penetrate inside the pocket formed as a result of SARS-CoV-2 receptor binding domain transition into the "open" state. The existence of binding site for cationic PSs common to the S-proteins of SARS-CoV, SARS-CoV-2, and MERS-CoV creates prospects for the wide use of this type of PSs to combat the spread of coronaviruses.


Subject(s)
Choline/metabolism , Indoles/metabolism , Isoindoles/metabolism , Middle East Respiratory Syndrome Coronavirus/chemistry , Organometallic Compounds/metabolism , Photosensitizing Agents/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Zinc Compounds/metabolism , Binding Sites , Indoles/chemistry , Methylene Blue/metabolism , Models, Molecular , Molecular Dynamics Simulation , Organometallic Compounds/chemistry , Protein Conformation , Protein Domains , Protein Subunits/chemistry , SARS Virus/chemistry , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Static Electricity
15.
Mol Inform ; 40(8): e2100028, 2021 08.
Article in English | MEDLINE | ID: covidwho-1345038

ABSTRACT

The COVID-19 pandemic caused by the SARS-CoV-2 has mobilized scientific attention in search of a treatment. The cysteine-proteases, main protease (Mpro) and papain-like protease (PLpro) are important targets for antiviral drugs. In this work, we simulate the interactions between the Mpro and PLpro with Ebselen, its metabolites and derivatives with the aim of finding molecules that can potentially inhibit these enzymes. The docking data demonstrate that there are two main interactions between the thiol (-SH) group of Cys (from the protease active sites) and the electrophilic centers of the organoselenium molecules, i. e. the interaction with the carbonyl group (O=C… SH) and the interaction with the Se moiety (Se… SH). Both interactions may lead to an adduct formation and enzyme inhibition. Density Functional Theory (DFT) calculations with Ebselen indicate that the energetics of the thiol nucleophilic attack is more favorable on Se than on the carbonyl group, which is in accordance with experimental data (Jin et al. Nature, 2020, 582, 289-293). Therefore, organoselenium molecules should be further explored as inhibitors of the SARS-CoV-2 proteases. Furthermore, we suggest that some metabolites of Ebselen (e. g. Ebselen diselenide and methylebselenoxide) and derivatives ethaselen and ebsulfur should be tested in vitro as inhibitors of virus replication and its proteases.


Subject(s)
Azoles/pharmacology , COVID-19/drug therapy , Coronavirus Papain-Like Proteases/metabolism , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/drug effects , Viral Matrix Proteins/metabolism , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Azoles/chemistry , Azoles/metabolism , COVID-19/metabolism , Catalytic Domain/drug effects , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Drug Discovery , Humans , Isoindoles , Molecular Docking Simulation , Organoselenium Compounds/chemistry , Organoselenium Compounds/metabolism , Protease Inhibitors/chemistry , Protease Inhibitors/metabolism , Viral Matrix Proteins/antagonists & inhibitors
16.
Molecules ; 26(14)2021 Jul 12.
Article in English | MEDLINE | ID: covidwho-1323315

ABSTRACT

Ebselen is the leader of selenorganic compounds, and starting from its identification as mimetic of the key antioxidant enzyme glutathione peroxidase, several papers have appeared in literature claiming its biological activities. It was the subject of several clinical trials and it is currently in clinical evaluation for the treatment of COVID-19 patients. Given our interest in the synthesis and pharmacological evaluation of selenorganic derivatives with this review, we aimed to collect all the papers focused on the biological evaluation of ebselen and its close analogues, covering the timeline between 2016 and most of 2021. Our analysis evidences that, even if it lacks specificity when tested in vitro, being able to bind to every reactive cysteine, it proved to be always well tolerated in vivo, exerting no sign of toxicity whatever the administered doses. Besides, looking at the literature, we realized that no review article dealing with the synthetic approaches for the construction of the benzo[d][1,2]-selenazol-3(2H)-one scaffold is available; thus, a section of the present review article is completely devoted to this specific topic.


Subject(s)
Azoles/chemistry , Azoles/chemical synthesis , Azoles/pharmacology , Organoselenium Compounds/chemistry , Organoselenium Compounds/chemical synthesis , Organoselenium Compounds/pharmacology , Animals , Anti-Infective Agents/pharmacology , Antioxidants/pharmacology , Antiviral Agents/pharmacology , Biomimetics/methods , Cyclooxygenase Inhibitors/pharmacology , Glutathione Peroxidase/metabolism , Glutathione Peroxidase/pharmacology , Humans , Isoindoles , Molecular Structure , Neuroprotective Agents/pharmacology , Selenium/chemistry , Selenoproteins/chemical synthesis , Selenoproteins/pharmacology
17.
Biochem J ; 478(13): 2499-2515, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1291175

ABSTRACT

The coronavirus 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spread around the world with unprecedented health and socio-economic effects for the global population. While different vaccines are now being made available, very few antiviral drugs have been approved. The main viral protease (nsp5) of SARS-CoV-2 provides an excellent target for antivirals, due to its essential and conserved function in the viral replication cycle. We have expressed, purified and developed assays for nsp5 protease activity. We screened the nsp5 protease against a custom chemical library of over 5000 characterised pharmaceuticals. We identified calpain inhibitor I and three different peptidyl fluoromethylketones (FMK) as inhibitors of nsp5 activity in vitro, with IC50 values in the low micromolar range. By altering the sequence of our peptidomimetic FMK inhibitors to better mimic the substrate sequence of nsp5, we generated an inhibitor with a subnanomolar IC50. Calpain inhibitor I inhibited viral infection in monkey-derived Vero E6 cells, with an EC50 in the low micromolar range. The most potent and commercially available peptidyl-FMK compound inhibited viral growth in Vero E6 cells to some extent, while our custom peptidyl FMK inhibitor offered a marked antiviral improvement.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Drug Evaluation, Preclinical , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Azoles/pharmacology , Chlorocebus aethiops , Coronavirus 3C Proteases/genetics , Coronavirus 3C Proteases/isolation & purification , Coronavirus 3C Proteases/metabolism , Enzyme Assays , Fluorescence Resonance Energy Transfer , High-Throughput Screening Assays , Isoindoles , Leupeptins/pharmacology , Organoselenium Compounds/pharmacology , Peptidomimetics , RNA-Binding Proteins/metabolism , Reproducibility of Results , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Vero Cells , Viral Nonstructural Proteins/metabolism
18.
Mol Pharmacol ; 100(2): 155-169, 2021 08.
Article in English | MEDLINE | ID: covidwho-1242189

ABSTRACT

The 14-3-3 proteins constitute a family of adaptor proteins with many binding partners and biological functions, and they are considered promising drug targets in cancer and neuropsychiatry. By screening 1280 small-molecule drugs using differential scanning fluorimetry (DSF), we found 15 compounds that decreased the thermal stability of 14-3-3ζ Among these compounds, ebselen was identified as a covalent, destabilizing ligand of 14-3-3 isoforms ζ, ε, γ, and η Ebselen bonding decreased 14-3-3ζ binding to its partner Ser19-phosphorylated tyrosine hydroxylase. Characterization of site-directed mutants at cysteine residues in 14-3-3ζ (C25, C94, and C189) by DSF and mass spectroscopy revealed covalent modification by ebselen of all cysteines through a selenylsulfide bond. C25 appeared to be the preferential site of ebselen interaction in vitro, whereas modification of C94 was the main determinant for protein destabilization. At therapeutically relevant concentrations, ebselen and ebselen oxide caused decreased 14-3-3 levels in SH-SY5Y cells, accompanied with an increased degradation, most probably by the ubiquitin-dependent proteasome pathway. Moreover, ebselen-treated zebrafish displayed decreased brain 14-3-3 content, a freezing phenotype, and reduced mobility, resembling the effects of lithium, consistent with its proposed action as a safer lithium-mimetic drug. Ebselen has recently emerged as a promising drug candidate in several medical areas, such as cancer, neuropsychiatric disorders, and infectious diseases, including coronavirus disease 2019. Its pleiotropic actions are attributed to antioxidant effects and formation of selenosulfides with critical cysteine residues in proteins. Our work indicates that a destabilization of 14-3-3 may affect the protein interaction networks of this protein family, contributing to the therapeutic potential of ebselen. SIGNIFICANCE STATEMENT: There is currently great interest in the repurposing of established drugs for new indications and therapeutic targets. This study shows that ebselen, which is a promising drug candidate against cancer, bipolar disorder, and the viral infection coronavirus disease 2019, covalently bonds to cysteine residues in 14-3-3 adaptor proteins, triggering destabilization and increased degradation in cells and intact brain tissue when used in therapeutic concentrations, potentially explaining the behavioral, anti-inflammatory, and antineoplastic effects of this drug.


Subject(s)
14-3-3 Proteins/chemistry , 14-3-3 Proteins/metabolism , Cysteine/genetics , Isoindoles/pharmacology , Organoselenium Compounds/pharmacology , 14-3-3 Proteins/genetics , Animals , Binding Sites/drug effects , Brain/metabolism , Cell Line , Circular Dichroism , Down-Regulation , Female , Humans , Male , Models, Molecular , Mutagenesis, Site-Directed , Protein Binding/drug effects , Protein Conformation , Protein Stability/drug effects , Tyrosine 3-Monooxygenase/metabolism , Zebrafish , Zebrafish Proteins/chemistry , Zebrafish Proteins/metabolism
19.
Viruses ; 13(4)2021 04 09.
Article in English | MEDLINE | ID: covidwho-1178430

ABSTRACT

Photodynamic inactivation of pathogenic microorganisms can be successfully used to eradicate pathogens in localized lesions, infected liquid media, and on various surfaces. This technique utilizes the photosensitizer (PS), light, and molecular oxygen to produce reactive oxygen species that kill pathogens. Here, we used the PS, water soluble octakis(cholinyl)zinc phthalocyanine (Zn-PcChol8+), to inactivate an initial 4.75-5.00 IgTCID50/mL titer of SARS-CoV-2, thereby preventing viral infection when tested in Vero E6 cell cultures. Zn-PcChol8+ in a minimally studied concentration, 1 µM and LED 3.75 J/cm2, completely destroyed the infectivity of SARS-CoV-2. To detect possible PS binding sites on the envelope of SARS-CoV-2, we analyzed electrostatic potential and simulated binding of Zn-PcChol8+ to the spike protein of this coronavirus by means of Brownian dynamics software, ProKSim (Protein Kinetics Simulator). Most of the Zn-PcChol8+ molecules formed clusters at the upper half of the stalk within a vast area of negative electrostatic potential. Positioning of the PS on the surface of the spike protein at a distance of no more than 10 nm from the viral membrane may be favorable for the oxidative damage. The high sensitivity of SARS-CoV-2 to photodynamic inactivation by Zn-PcChol8+ is discussed with respect to the application of this PS to control the spread of COVID-19.


Subject(s)
Indoles/pharmacology , Organometallic Compounds/pharmacology , Photosensitizing Agents/pharmacology , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/chemistry , Virus Inactivation/drug effects , Animals , COVID-19/prevention & control , Chlorocebus aethiops , Indoles/chemistry , Isoindoles , Light , Molecular Dynamics Simulation , Organometallic Compounds/chemistry , Photosensitizing Agents/chemistry , Vero Cells , Zinc Compounds
20.
Arch Toxicol ; 95(4): 1179-1226, 2021 04.
Article in English | MEDLINE | ID: covidwho-1162995

ABSTRACT

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.


Subject(s)
Organoselenium Compounds/pharmacology , Organoselenium Compounds/toxicity , Amino Acids/chemistry , Animals , Azoles , Humans , Isoindoles , Molecular Structure , Selenium/chemistry , Selenium/physiology , Selenoproteins/chemistry , Sulfhydryl Compounds/chemistry
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