scholarly journals Review of Phytochemical Compounds as Antiviral Agents Against Arboviruses from the Genera Flavivirus and Alphavirus

2020 ◽  
Vol 17 (4) ◽  
pp. 484-497
Author(s):  
Samira Sardari ◽  
Mahmoud Rafieian-Kopaei ◽  
Khojasteh Malekmohammad ◽  
Robert D.E. Sewell
Keyword(s):  
Antiviral Agents ◽  
Emerging Infectious Diseases ◽  
Diverse Group ◽  
Inhibitory Effects ◽  
Public Health Perspective ◽  
The Past ◽  
Antiviral Compounds ◽  
Viral Mutation ◽  
The World ◽  
Phytochemical Compounds

Arboviruses are a diverse group of viruses that are among the major causes of emerging infectious diseases. Arboviruses from the genera flavivirus and alphavirus are the most important human arboviruses from a public health perspective. During recent decades, these viruses have been responsible for millions of infections and deaths around the world. Over the past few years, several investigations have been carried out to identify antiviral agents to treat these arbovirus infections. The use of synthetic antiviral compounds is often unsatisfactory since they may raise the risk of viral mutation; they are costly and possess either side effects or toxicity. One attractive strategy is the use of plants as promising sources of novel antiviral compounds that present significant inhibitory effects on these viruses. In this review, we describe advances in the exploitation of compounds and extracts from natural sources that target the vital proteins and enzymes involved in arbovirus replication.

scholarly journals Recent Advances in Tetrazole Derivatives as Potential Antiviral Agents

2021 ◽  
Vol 33 (11) ◽  
pp. 2599-2607
Author(s):  
Ruchika Yogesh ◽  
Noopur Srivastava
Keyword(s):  
Antiviral Agents ◽  
Acid Amide ◽  
Host Cells ◽  
Carboxylic Acid Amide ◽  
Synthetic Compounds ◽  
Scientific Databases ◽  
The Past ◽  
Antiviral Compounds ◽  
Pharmaceutical Agents ◽  
Tetrazole Derivatives

Viruses use the host cell’s biochemical machinery for replication and survival; and also undergo mutations to evade the immune response and achieve better transmission. These features make it challenging to develop selective drugs to kill viruses only and not the host cells. New and effective pharmaceutical agents are required to overcome this challenge. Tetrazole moiety, as a bio-isostere of carboxylic acid/amide group, has been extensively used as a potent pharmacophore in several bioactivities. Intrigued by the necessity of finding new antiviral compounds and tendency of tetrazole scaffolds to render various bioactivity profiles, this review article comprising literature reports of tetrazole-based synthetic compounds with promising antiviral activity is presented. This review comprises significant literature reports from the scientific databases published during the past four decades. It is found that tetrazole based molecules are promising endeavor for the development of potential agents against influenza virus, HIV, HCV and other viruses.

scholarly journals Secondary Metabolites from Caulerpa Cylindracea (Sonder) Could Be Alternative Natural Antiviral Compounds for COVID-19: A Further in Silico Proof

2020 ◽  
Author(s):  
Levent Çavaş ◽  
Cengizhan Dag ◽  
Miguel Carmena-Barreño ◽  
Carlos Martínez-Cortés ◽  
José Pedro Cerón-Carrasco ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Vaccine Development ◽  
Antiviral Agents ◽  
Binding Energies ◽  
Antiviral Compounds ◽  
Main Protease ◽  
The Us ◽  
The World ◽  
Molecular Dynamics Results ◽  
Spreading Property

<p>SARS-CoV-2 has been exhibiting extremely spreading property all around the world since its existence from Wuhan-China in December-2019. Although it has caused a death toll of over than 1.3 M people, no validated vaccine has been proposed yet. On the other hand, very dense studies on the vaccine development have been carrying out in some countries such as the US, Germany, UK, China and Russia. Due to side effects of current antiviral agents used in the therapy of COVID-19, there is a great need for the development of alternative compounds for this disease. Caulerpin (CPN) and caulerpenyne (CYN), predominant natural secondary metabolites from invasive marine green algae <i>Caulerpa cylindracea,</i>are proposed to neutralize the virus from two targets: spike protein (5XLR) and main protease (6YB7) in this study. The results show that the binding energies related to CPN-6YB7 and CYN-6YB7 interactions are found to be -8.02 kcal/mol and -6.83 kcal/mol, respectively. The binding energies were -9.68 kcal/mol and -7.53 kcal/mol, respectively, for CPN-5XLR and CYN-5XLR. In the molecular dynamics results, RMSD values show that CPN and CYN can form stable complexes with the proteins where CYN is more stable with 6YB7 and CPN interacts better with 5XLR. These differences seem to be based on the type of interactions of the complexes. In conclusion, caulerpin and caulerpenyne can further be investigated experimentally for their anti-SARS-CoV-2 efficiency. </p>

scholarly journals Secondary Metabolites from Caulerpa Cylindracea (Sonder) Could Be Alternative Natural Antiviral Compounds for COVID-19: A Further in Silico Proof

2020 ◽  
Author(s):  
Levent Çavaş ◽  
Cengizhan Dag ◽  
Miguel Carmena-Bargueño ◽  
Carlos Martínez-Cortés ◽  
José Pedro Cerón-Carrasco ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Vaccine Development ◽  
Antiviral Agents ◽  
Binding Energies ◽  
Antiviral Compounds ◽  
Main Protease ◽  
The Us ◽  
The World ◽  
Molecular Dynamics Results ◽  
Spreading Property

<p>SARS-CoV-2 has been exhibiting extremely spreading property all around the world since its existence from Wuhan-China in December-2019. Although it has caused a death toll of over than 1.3 M people, no validated vaccine has been proposed yet. On the other hand, very dense studies on the vaccine development have been carrying out in some countries such as the US, Germany, UK, China and Russia. Due to side effects of current antiviral agents used in the therapy of COVID-19, there is a great need for the development of alternative compounds for this disease. Caulerpin (CPN) and caulerpenyne (CYN), predominant natural secondary metabolites from invasive marine green algae <i>Caulerpa cylindracea,</i>are proposed to neutralize the virus from two targets: spike protein (5XLR) and main protease (6YB7) in this study. The results show that the binding energies related to CPN-6YB7 and CYN-6YB7 interactions are found to be -8.02 kcal/mol and -6.83 kcal/mol, respectively. The binding energies were -9.68 kcal/mol and -7.53 kcal/mol, respectively, for CPN-5XLR and CYN-5XLR. In the molecular dynamics results, RMSD values show that CPN and CYN can form stable complexes with the proteins where CYN is more stable with 6YB7 and CPN interacts better with 5XLR. These differences seem to be based on the type of interactions of the complexes. In conclusion, caulerpin and caulerpenyne can further be investigated experimentally for their anti-SARS-CoV-2 efficiency. </p>

scholarly journals Bioinformatic Analysis of Antiviral Medicinal Compounds Against Sars Cov-2 Proteases

2021 ◽  
Author(s):  
Fahad Hassan Shah ◽  
◽  
Kyeong Ho Lim ◽  
Song Ja Kim ◽  
◽  
...  
Keyword(s):  
Antiviral Agents ◽  
Respiratory Illness ◽  
Bioinformatic Analysis ◽  
Antiviral Compounds ◽  
Medicinal Compounds ◽  
Global Pandemic ◽  
Viral Proteases ◽  
The World ◽  
Severe Respiratory Illness ◽  
Probable Interaction

The world is under siege from a global pandemic caused by a novel class of coronaviruses called severe acute respiratory syndrome coronavirus-2 (SARS CoV-2). These viruses cause severe respiratory illness leading to death. Molecular studies reveal that SARS CoV-2 proteases are involved in the processing of viral polyproteins. This study was conducted to obtain antiviral agents for SARS CoV-2 proteases. An extensive library of antiviral medicinal compounds was scrutinized to determine the probable interaction with both main and 3-chymotrypsin like proteases. Six antiviral compounds (Abietic Acid, Gallic Acid, Piceatannol, Piperine, Sinomenine, and Triptolide) were capable of establishing hydrogen bonds with the active pocket residues of the viral proteases, with appreciable binding energy. These compounds were subjected to root mean square analysis and tested not only for acute toxicity, but also for absorption, distribution, metabolism, excretion, and toxicity properties. Results were favourable for use in the treatment of SARS COV-2 infection.

scholarly journals Secondary Metabolites from Caulerpa Cylindracea (Sonder) Could Be Alternative Natural Antiviral Compounds for COVID-19: A Further in Silico Proof

2020 ◽  
Author(s):  
Levent Çavaş ◽  
Cengizhan Dag ◽  
Miguel Carmena-Bargueño ◽  
Carlos Martínez-Cortés ◽  
José Pedro Cerón-Carrasco ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Vaccine Development ◽  
Antiviral Agents ◽  
Binding Energies ◽  
Antiviral Compounds ◽  
Main Protease ◽  
The Us ◽  
The World ◽  
Molecular Dynamics Results ◽  
Spreading Property

<p>SARS-CoV-2 has been exhibiting extremely spreading property all around the world since its existence from Wuhan-China in December-2019. Although it has caused a death toll of over than 1.3 M people, no validated vaccine has been proposed yet. On the other hand, very dense studies on the vaccine development have been carrying out in some countries such as the US, Germany, UK, China and Russia. Due to side effects of current antiviral agents used in the therapy of COVID-19, there is a great need for the development of alternative compounds for this disease. Caulerpin (CPN) and caulerpenyne (CYN), predominant natural secondary metabolites from invasive marine green algae <i>Caulerpa cylindracea,</i>are proposed to neutralize the virus from two targets: spike protein (5XLR) and main protease (6YB7) in this study. The results show that the binding energies related to CPN-6YB7 and CYN-6YB7 interactions are found to be -8.02 kcal/mol and -6.83 kcal/mol, respectively. The binding energies were -9.68 kcal/mol and -7.53 kcal/mol, respectively, for CPN-5XLR and CYN-5XLR. In the molecular dynamics results, RMSD values show that CPN and CYN can form stable complexes with the proteins where CYN is more stable with 6YB7 and CPN interacts better with 5XLR. These differences seem to be based on the type of interactions of the complexes. In conclusion, caulerpin and caulerpenyne can further be investigated experimentally for their anti-SARS-CoV-2 efficiency. </p>

Biodiversity of the aculeate wasps (Hymenoptera: Aculeata) of the Arabian Peninsula: Preface

Zootaxa ◽  
2020 ◽  
Vol 4754 (1) ◽  
pp. 5-7
Author(s):  
NEVEEN S. GADALLAH ◽  
DENIS J. BROTHERS
Keyword(s):  
Arabian Peninsula ◽  
Focused Attention ◽  
Diverse Group ◽  
Ecological Studies ◽  
The Past ◽  
Additional Work ◽  
The World ◽  
Opportune Time ◽  
Taxonomic Changes ◽  
Available Information

During the past 20 decades, many taxonomic and ecological studies were undertaken on different taxa of a fascinating, biologically diverse group of insects, the aculeate wasps, in different areas of the Arabian Peninsula. These wasps comprise all Aculeata, except for the ants (Formicidae) and bees (Anthophila) which are specialized monophyletic groups that have attracted more focused attention across the world. The Arabian studies have been published in the form of scattered articles in various journals, newsletters, book chapters, etc., many being rather obscure and difficult to trace. Recently, the number of such studies has increased as a result of targeted collecting projects. The results of most of these have now been published, making this an opportune time to collect all the available information into a single volume that makes it more accessible to researchers interested in this group of insects. In the process, this provides us an opportunity to estimate the diversity and distributions of aculeate wasps in the Arabian countries. This is also important for the development of the Arabian national collections, especially in aggregating taxonomic changes with their subsequent synonymous forms and pointing out the very many gaps in sampling, so indicating where additional work is needed. 

A basic introduction to image processing using NIH-Image as a model

1994 ◽  
Vol 52 ◽  
pp. 392-393
Author(s):  
John Mansfield
Keyword(s):  
Image Processing ◽  
Digital Image ◽  
Image Acquisition ◽  
Digital Instrument ◽  
Novice User ◽  
Nih Image ◽  
The Past ◽  
Digital World ◽  
The World ◽  
Instrument Control

Advances in camera technology and digital instrument control have meant that in modern microscopy, the image that was, in the past, typically recorded on a piece of film is now recorded directly into a computer. The transfer of the analog image seen in the microscope to the digitized picture in the computer does not mean, however, that the problems associated with recording images, analyzing them, and preparing them for publication, have all miraculously been solved. The steps involved in the recording an image to film remain largely intact in the digital world. The image is recorded, prepared for measurement in some way, analyzed, and then prepared for presentation.Digital image acquisition schemes are largely the realm of the microscope manufacturers, however, there are also a multitude of “homemade” acquisition systems in microscope laboratories around the world. It is not the mission of this tutorial to deal with the various acquisition systems, but rather to introduce the novice user to rudimentary image processing and measurement.

On the Symbolism of Rain in A Farewell to Arms

2018 ◽  
Keyword(s):  
Research Tool ◽  
The Past ◽  
The World ◽  
Farewell To Arms

This paper critically analyzes the symbolic use of rain in A Farewell to Arms (1929). The researcher has applied the Sapir-Whorf Hypothesis as a research tool for the analysis of the text. This hypothesis argues that the languages spoken by a person determine how one observes this world and that the peculiarities encoded in each language are all different from one another. It affirms that speakers of different languages reflect the world in pretty different ways. Hemingway’s symbolic use of rain in A Farewell to Arms (1929) is denotative, connotative, and ironical. The narrator and protagonist, Frederick Henry symbolically embodies his own perceptions about the world around him. He time and again talks about rain when something embarrassing is about to ensue like disease, injury, arrest, retreat, defeat, escape, and even death. Secondly, Hemingway has connotatively used rain as a cleansing agent for washing the past memories out of his mind. Finally, the author has ironically used rain as a symbol when Henry insists on his love with Catherine Barkley while the latter being afraid of the rain finds herself dead in it.

Profilometry. Using Corneo-scleral topography for scleral lens fitting

The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 19-22
Author(s):  
Gregory DeNaeyer
Keyword(s):  
Ocular Surface ◽  
World Wide ◽  
Contact Lenses ◽  
The Past ◽  
The World ◽  
The Future ◽  
The Way

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.

Aftershocks

2017 ◽  
Author(s):  
Seva Gunitsky
Keyword(s):  
Twentieth Century ◽  
Regime Change ◽  
International System ◽  
Political Legitimacy ◽  
Great Powers ◽  
Past Century ◽  
The Past ◽  
Sudden Rise ◽  
The World ◽  
National Borders

Over the past century, democracy spread around the world in turbulent bursts of change, sweeping across national borders in dramatic cascades of revolution and reform. This book offers a new global-oriented explanation for this wavelike spread and retreat—not only of democracy but also of its twentieth-century rivals, fascism, and communism. The book argues that waves of regime change are driven by the aftermath of cataclysmic disruptions to the international system. These hegemonic shocks, marked by the sudden rise and fall of great powers, have been essential and often-neglected drivers of domestic transformations. Though rare and fleeting, they not only repeatedly alter the global hierarchy of powerful states but also create unique and powerful opportunities for sweeping national reforms—by triggering military impositions, swiftly changing the incentives of domestic actors, or transforming the basis of political legitimacy itself. As a result, the evolution of modern regimes cannot be fully understood without examining the consequences of clashes between great powers, which repeatedly—and often unsuccessfully—sought to cajole, inspire, and intimidate other states into joining their camps.

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