scholarly journals Alkyne-Tagged Apigenin, a Chemical Tool to Navigate Potential Targets of Flavonoid Anti-Dengue Leads

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6967
Author(s):  
Kowit Hengphasatporn ◽  
Benyapa Kaewmalai ◽  
Somruedee Jansongsaeng ◽  
Vishnu Nayak Badavath ◽  
Thanaphon Saelee ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Cycloaddition Reaction ◽  
Hydroxyl Group ◽  
Viral Translation ◽  
Chemically Modified ◽  
Chemical Tag ◽  
Infected Cells ◽  
Compound Signal ◽  
Infection Stage ◽  
Estrogen Receptor 1

A flavonoid is a versatile core structure with various cellular, immunological, and pharmacological effects. Recently, flavones have shown anti-dengue activities by interfering with viral translation and replication. However, the molecular target is still elusive. Here we chemically modified apigenin by adding an alkyne moiety into the B-ring hydroxyl group. The alkyne serves as a chemical tag for the alkyne-azide cycloaddition reaction for subcellular visualization. The compound located at the perinuclear region at 1 and 6 h after infection. Interestingly, the compound signal started shifting to vesicle-like structures at 6 h and accumulated at 24 and 48 h after infection. Moreover, the compound treatment in dengue-infected cells showed that the compound restricted the viral protein inside the vesicles, especially at 48 h. As a result, the dengue envelope proteins spread throughout the cells. The alkyne-tagged apigenin showed a more potent efficacy at the EC50 of 2.36 ± 0.22, and 10.55 ± 3.37 µM, respectively, while the cytotoxicities were similar to the original apigenin at the CC50 of 70.34 ± 11.79, and 82.82 ± 11.68 µM, respectively. Molecular docking confirmed the apigenin binding to the previously reported target, ribosomal protein S9, at two binding sites. The network analysis, homopharma, and molecular docking revealed that the estrogen receptor 1 and viral NS1 were potential targets at the late infection stage. The interactions could attenuate dengue productivity by interfering with viral translation and suppressing the viral proteins from trafficking to the cell surface.

scholarly journals Diacetate Naphthoquinone Derivatives Tethered to 1,2,3-Triazoles: Synthesis and Cytotoxicity Evaluation in Caco-2 Cells

2021 ◽  
Author(s):  
Dora Costa ◽  
Adriane Francisco ◽  
Beatriz Matuck ◽  
Priscila Furtado ◽  
Alana de Oliveira ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Acetic Anhydride ◽  
Cytotoxic Activity ◽  
Ammonium Nitrate ◽  
Topoisomerase Ii ◽  
Cycloaddition Reaction ◽  
Selectivity Index ◽  
Ceric Ammonium Nitrate ◽  
Metallic Zinc ◽  
Synthetic Route

Acetylated compounds prepared from naphthoquinones have been reported as antitumoral prodrugs. Exploring the synthetic versatility of the naphthoquinone and triazolic nuclei, herein we report a simple and efficient synthetic route to prepare a series of sixteen prodrugs prototype of 1,2,3-triazoles-naphthoquinodoic acetyl derivatives. The compounds 10a-10h and 11a-11h were obtained by oxidative cycloaddition reaction between lawsone and 4-vinyl-1H-1,2,3-triazoles promoted by ceric ammonium nitrate (CAN) in alkaline medium followed by reductive acetylation of the quinones in excess of metallic zinc and acetic anhydride in yields up to > 98%. All derivatives revealed to be hemocompatible and the compound 11e exhibited the most promising profile against Caco-2 cells showing the higher selectivity index. Molecular docking suggests that these compounds could exert their cytotoxic activity through inhibition of one topoisomerase II isoform, at least.

scholarly journals The catalytic activity of copper nanoparticles on aminomodified silica support in the flow azide-alkyne cycloaddition reaction using macrocyclic substrates

2019 ◽  
Vol 57 (2) ◽  
pp. 1-9
Author(s):  
Albina T. Nurmukhametova ◽  
◽  
Roman N. Belov ◽  
Vladimir A. Burilov ◽  
Igor S. Antipin ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Chemical Reduction ◽  
Cycloaddition Reaction ◽  
Nitrogen Adsorption ◽  
Propargyl Alcohol ◽  
Hydroxyl Group ◽  
Aryl Azides ◽  
Consecutive Reaction ◽  
Inductively Coupled

Using the chemical reduction method, a copper-containing catalyst on an amino-modified silica was obtained. The structure and composition of the catalyst were characterized by low-temperature nitrogen adsorption and inductively coupled plasma mass spectrometry. It was found that the modification of silica with amino groups and copper nanoparticles leads to a significant change in textural characteristics: nanoparticles and the modifier fill the pores in the size range of 5-10 nm. Obtained catalyst showed good activity in the flow cycloaddition of azides and alkynes of various nature. The comparative activity of azides and alkynes was analyzed. It has been established that among the azides studied (benzyl azide, p-nitrobenzylazide, p-methoxybenzylazide, 2-azidoethylacetate and 1-azidodecane), alkyl and aryl azides with electron-withdrawing groups were most active due to an increase in the electrophilicity of the terminal nitrogen atom of the azide group. Among the studied acetylenes (phenylacetylene, hexin-1, trimethylsilylacetylene and propargyl alcohol), propargyl alcohol was the most and trimethylsilylacetylene was the less active. Increased activity of propargyl alcohol may be due to a donor hydroxyl group capable of coordinating with copper; reduced activity of trimethylsilylacetylene can be resulted from steric hindrances. p-tert-Butyl and p-H-calix[4]arens were also used in the reaction. Full conversion of macrocycles was achieved after 3 consecutive reaction cycles. The resulting triazoles were isolated and characterized by a complex of physical methods. Thus, It has been demonstrated that carrying out the reaction in a flow by maintaining stable and fully reproducible reaction parameters makes it possible to quickly evaluate the relative reactivity of molecules.

scholarly journals Disruption of Stress Granule Formation by the Multifunctional Cricket Paralysis Virus 1A Protein

2016 ◽  
Vol 91 (5) ◽  
Author(s):  
Anthony Khong ◽  
Craig H. Kerr ◽  
Clarence H. L. Yeung ◽  
Kathleen Keatings ◽  
Arabinda Nayak ◽  
...  
Keyword(s):  
Virus Infection ◽  
Stress Granule ◽  
Granule Formation ◽  
Viral Translation ◽  
Content Type ◽  
Cellular Processes ◽  
Cellular Environment ◽  
Viral Yield ◽  
Infected Cells ◽  
Paralysis Virus

ABSTRACT Stress granules (SGs) are cytosolic ribonucleoprotein aggregates that are induced during cellular stress. Several viruses modulate SG formation, suggesting that SGs have an impact on virus infection. However, the mechanisms and impact of modulating SG assembly in infected cells are not completely understood. In this study, we identify the dicistrovirus cricket paralysis virus 1A (CrPV-1A) protein that functions to inhibit SG assembly during infection. Moreover, besides inhibiting RNA interference, CrPV-1A also inhibits host transcription, which indirectly modulates SG assembly. Thus, CrPV-1A is a multifunctional protein. We identify a key R146A residue that is responsible for these effects, and mutant CrPV(R146A) virus infection is attenuated in Drosophila melanogaster S2 cells and adult fruit flies and results in increased SG formation. Treatment of CrPV(R146A)-infected cells with actinomycin D, which represses transcription, restores SG assembly suppression and viral yield. In summary, CrPV-1A modulates several cellular processes to generate a cellular environment that promotes viral translation and replication. IMPORTANCE RNA viruses encode a limited set of viral proteins to modulate an array of cellular processes in order to facilitate viral replication and inhibit antiviral defenses. In this study, we identified a viral protein, called CrPV-1A, within the dicistrovirus cricket paralysis virus that can inhibit host transcription, modulate viral translation, and block a cellular process called stress granule assembly. We also identified a specific amino acid within CrPV-1A that is important for these cellular processes and that mutant viruses containing mutations of CrPV-1A attenuate virus infection. We also demonstrate that the CrPV-1A protein can also modulate cellular processes in human cells, suggesting that the mode of action of CrPV-1A is conserved. We propose that CrPV-1A is a multifunctional, versatile protein that creates a cellular environment in virus-infected cells that permits productive virus infection.

Synthesis, Molecular Docking and In Vivo Biological Evaluation of Iminostilbene Linked 1,2,3-Triazole Pharmacophores as Promising AntiAnxiety and Anti-Inflammatory Agents

2021 ◽  
Vol 17 ◽  
Author(s):  
Kariyappa N. Ankali ◽  
Javarappa Rangaswamy ◽  
Mallappa Shalavadi ◽  
Nagaraja Naik
Keyword(s):  
Molecular Docking ◽  
Cycloaddition Reaction ◽  
Triazole Ring ◽  
Docking Studies ◽  
Biological Evaluation ◽  
Gaba A ◽  
Chemical Structures ◽  
Rat Paw Edema ◽  
Anti Inflammatory

Background: Iminostilbene and 1,2,3-triazole ring containing compounds are considered as beneficial substrates in drug design. Objectives: This study was aimed at the synthesis of novel series of iminostilbene linked 1,2,3- triazole pharmacophores (7c-n) by Cu(I) catalyzed 1,3 dipolar cycloaddition reaction between 5- (Prop-2-yn-1-yl)-5H-dibenzo[b,f]azepine (7b) and various substituted azidobenzene derivatives (3cn). Methods: The chemical structures of compounds were confirmed by 1 H NMR, 13C NMR, LC-MS and molecular docking studies were carried out through HEX docking software. Results: The in vivo anti anxiety capacity of the compounds was evaluated by using “elevated plus maze” (EPM), anxiety model. The results exhibited that compounds (7d, 7e, 7j and 7k) have a higher anti anxiety effect close to diazepam. The anti-inflammatory activities of the synthesized compounds were evaluated by “Carrageenan-induced rat paw edema” model, compounds (7b, 7c, 7d, 7f, and 7j) demonstrated statistically significant inflammatory activity. Molecular docking analysis revealed that compounds (7d, 7e and 7j) bound to GABA(A) proteins show more efficiency when compared to the other analogues in the series. Conclusion: These results suggest that compounds (7b, 7c, 7d, 7e, 7f, and 7j) can be considered as novel candidates for anti-anxiety and anti-inflammatory agents. Moreover, docking method was used to elucidate anti-anxiety effect of compounds. This study furnished insight into the molecular interactions of synthesized compounds with their physiological targets, and the potential to develop bioactive heterocyclic compounds.

New Strategy of Synthesis of Peramivir Analogues as Potential Neuraminidase Inhibitors

Synthesis ◽  
2019 ◽  
Vol 52 (06) ◽  
pp. 933-941
Author(s):  
Roberta Bartolotta ◽  
Concetta La Rosa ◽  
Donatella Nava
Keyword(s):  
Cycloaddition Reaction ◽  
Nitrile Oxide ◽  
Hydroxyl Group ◽  
Dipolar Cycloaddition ◽  
Carbon Nucleus ◽  
Neuraminidase Inhibitors ◽  
Subsequent Reaction ◽  
New Strategy

Highly functionalised potential neuraminidase (NA) inhibitors, analogues of peramivir, were synthesised via a new and versatile method starting from a stereoselective 1,3-dipolar cycloaddition reaction between the nitrile oxide derived from 2-ethylbutanal and the commercially available and inexpensive cyclopentadiene and 1,3-cyclohexadiene, which afforded the isoxazolino-cyclopentene or cyclohexene intermediates, respectively. The subsequent reaction of the C=C bond in different conditions allowed the functionalisation of the five (or six) membered carbon nucleus. Further functionalised derivatives displaying an amino and a hydroxyl group were achieved via the final opening of the isoxazoline ring.

scholarly journals Viral Translation Is Coupled to Transcription in Sindbis Virus-Infected Cells

2007 ◽  
Vol 81 (13) ◽  
pp. 7061-7068 ◽  
Author(s):  
Miguel A. Sanz ◽  
Alfredo Castelló ◽  
Luis Carrasco
Keyword(s):  
Sindbis Virus ◽  
Late Phase ◽  
Mrna Translation ◽  
Encephalomyocarditis Virus ◽  
Host Protein ◽  
Viral Mrnas ◽  
Viral Translation ◽  
Bhk Cells ◽  
Infected Cells

ABSTRACT During the late phase of Sindbis virus infection, the viral subgenomic mRNA is translated efficiently in BHK cells, whereas host protein synthesis is inhibited. However, transfection of in vitro-generated Sindbis virus subgenomic mRNA leads to efficient translation in uninfected BHK cells, whereas it is a poor substrate in infected cells. Therefore, the structure of the subgenomic mRNA itself is not sufficient to confer its translatability in infected cells. In this regard, translation of the subgenomic mRNA requires synthesis from the viral transcription machinery. The lack of translation of transfected viral mRNAs in infected cells is not due to their degradation nor is it a consequence of competition between viral transcripts and transfected mRNAs, because a replicon that cannot produce subgenomic mRNA also interferes with exogenous mRNA translation. Interestingly, subgenomic mRNA is translated more efficiently when it is transfected into uninfected cells than when it is transcribed from a transfected replicon. Finally, a similar behavior was observed for other RNA viruses, such as vesicular stomatitis virus and encephalomyocarditis virus. These findings support the notion that translation is coupled to transcription in cells infected with different animal viruses.

scholarly journals Rice Plasma Membrane Proteomics Reveals Magnaporthe oryzae Promotes Susceptibility by Sequential Activation of Host Hormone Signaling Pathways

2016 ◽  
Vol 29 (11) ◽  
pp. 902-913 ◽  
Author(s):  
Jidong Cao ◽  
Chao Yang ◽  
Lingjuan Li ◽  
Lan Jiang ◽  
Yao Wu ◽  
...  
Keyword(s):  
Immune Response ◽  
Plasma Membrane ◽  
Magnaporthe Oryzae ◽  
Transmembrane Domain ◽  
Protein Composition ◽  
Aba Signaling ◽  
Massive Growth ◽  
Genes Expression ◽  
Infected Cells ◽  
Infection Stage

Plant plasma membrane (PM) plays important roles in immune response. Here, we utilized quantitative mass spectrometry to explore rice PM protein composition and dynamic changes during Magnaporthe oryzae infection. We report, thus far, the largest rice PM proteome dataset with 3,906 identified proteins, among which 484 proteins were differentially expressed after M. oryzae infection. One third of the identified proteins are predicted to have at least one transmembrane domain. Half of the identified proteins are predicted to have binding functions and over one third of the proteins have enzyme-related functions. In addition, Gene Ontology analyses revealed that abscisic acid (ABA) and cytokinin (CK) signaling were sequentially activated after M. oryzae infection in rice. We found that the activation of ABA signaling and the suppression of rice immune response occurred at the early infection stage, while the activation of CK signaling, the upregulation of sugar transporter genes expression, and the nutrient efflux of infected rice cells occurred at later infection stage. Thus, we further propose that M. oryzae activates ABA signaling to repress rice immune signaling for initial invasion and redirects nutrient efflux of infected cells for massive growth at the later infection stage.

Orobol: An Inhibitor of Vesicular Stomatitis Virus that Blocks the Synthesis of Viral Nucleic Acids and the Glycosylation of G Protein

1994 ◽  
Vol 5 (2) ◽  
pp. 99-104 ◽  
Author(s):  
M. J. Almela ◽  
A. Irurzun ◽  
L. Carrasco
Keyword(s):  
Protein Synthesis ◽  
Nucleic Acids ◽  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Viral Protein Synthesis ◽  
Viral Translation ◽  
Naturally Occurring ◽  
Infected Cells ◽  
Vesicular Stomatitis ◽  
Virus Influenza

The naturally occurring isoflavonoid orobol exhibits antiviral effects against some animal viruses. Addition of the compound after virus entry inhibits the appearance of late viral protein synthesis in Vesicular Stomatitis Virus, influenza, or vaccinia virus-infected cells, but has no effect on poliovirus protein synthesis. Concentrations of the compound above 10–50 Mg ml−1 are sufficient to decrease the synthesis of VSV proteins when added early during infection, but have no effect on viral translation if added later, indicating that orobol does not block VSV translation directly. The synthesis of VSV nucleic acids is one of the targets of this flavonoid. The synthesis of both minus and plus-stranded viral RNA are inhibited by orobol when added during the first 2 h of infection. In addition, this compound interferes potently with the glycosylation of VSV G protein, indicating that orobol has several targets of antiviral action. The possibility that orobol interferes with the function of the cellular vesicular system is discussed.

scholarly journals Inhibition of Stress Granule Formation by Middle East Respiratory Syndrome Coronavirus 4a Accessory Protein Facilitates Viral Translation, Leading to Efficient Virus Replication

2018 ◽  
Vol 92 (20) ◽  
Author(s):  
Keisuke Nakagawa ◽  
Krishna Narayanan ◽  
Masami Wada ◽  
Shinji Makino
Keyword(s):  
Middle East ◽  
Virus Replication ◽  
Stress Responses ◽  
Middle East Respiratory Syndrome ◽  
Stress Granule ◽  
Accessory Protein ◽  
Viral Mrnas ◽  
Translation Arrest ◽  
Viral Translation ◽  
Infected Cells

ABSTRACTStress granule (SG) formation is generally triggered as a result of stress-induced translation arrest. The impact of SG formation on virus replication varies among different viruses, and the significance of SGs in coronavirus (CoV) replication is largely unknown. The present study examined the biological role of SGs in Middle East respiratory syndrome (MERS)-CoV replication. The MERS-CoV 4a accessory protein is known to inhibit SG formation in cells in which it was expressed by binding to double-stranded RNAs and inhibiting protein kinase R (PKR)-mediated phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α). Replication of MERS-CoV lacking the genes for 4a and 4b (MERS-CoV-Δp4), but not MERS-CoV, induced SG accumulation in MERS-CoV-susceptible HeLa/CD26 cells, while replication of both viruses failed to induce SGs in Vero cells, demonstrating cell type-specific differences in MERS-CoV-Δp4-induced SG formation. MERS-CoV-Δp4 replicated less efficiently than MERS-CoV in HeLa/CD26 cells, and inhibition of SG formation by small interfering RNA-mediated depletion of the SG components promoted MERS-CoV-Δp4 replication, demonstrating that SG formation was detrimental for MERS-CoV replication. Inefficient MERS-CoV-Δp4 replication was not due to either the induction of type I and type III interferons or the accumulation of viral mRNAs in the SGs. Rather, it was due to the inefficient translation of viral proteins, which was caused by high levels of PKR-mediated eIF2α phosphorylation and likely by the confinement of various factors that are required for translation in the SGs. Finally, we established that deletion of the 4a gene alone was sufficient for inducing SGs in infected cells. Our study revealed that 4a-mediated inhibition of SG formation facilitates viral translation, leading to efficient MERS-CoV replication.IMPORTANCEMiddle East respiratory syndrome coronavirus (MERS-CoV) causes respiratory failure with a high case fatality rate in patients, yet effective antivirals and vaccines are currently not available. Stress granule (SG) formation is one of the cellular stress responses to virus infection and is generally triggered as a result of stress-induced translation arrest. SGs can be beneficial or detrimental for virus replication, and the biological role of SGs in CoV infection is unclear. The present study showed that the MERS-CoV 4a accessory protein, which was reported to block SG formation in cells in which it was expressed, inhibited SG formation in infected cells. Our data suggest that 4a-mediated inhibition of SG formation facilitates the translation of viral mRNAs, resulting in efficient virus replication. To our knowledge, this report is the first to show the biological significance of SG in CoV replication and provides insight into the interplay between MERS-CoV and antiviral stress responses.

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