Targeting SARS-CoV-2 main protease: a comprehensive approach using advanced virtual screening, molecular dynamics, and in vitro validation.

The COVID-19 pandemic, driven by the SARS-CoV-2 virus, necessitates the development of effective therapeutics. The main protease of the virus, Mpro, is a key target due to its crucial role in viral replication. Our study presents a novel approach combining ligand-based pharmacophore modeling with structure-based advanced virtual screening to identify potential inhibitors of Mpro.

Development of a water-dispersible antimicrobial lipid mixture to inhibit African swine fever virus and other enveloped viruses.

Medium-chain antimicrobial lipids are promising antiviral agents to inhibit membrane-enveloped viruses such as African swine fever virus (ASFV) and influenza A virus (IAV) in livestock applications. However, current uses are limited to feed pathogen mitigation due to low aqueous solubility and the development of water-dispersible lipid formulations is needed for broader application usage. In this study, we report a water-dispersible antimicrobial lipid mixture of monoglycerides and lactylates that can inhibit ASFV and IAV and exhibits antiviral properties in drinking water and feed matrices.

Computational evaluation and benchmark study of 342 crystallographic holo-structures of SARS-CoV-2 Mpro enzyme.

The coronavirus disease 19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a global health crisis with millions of confirmed cases and related deaths. The main protease (Mpro) of SARS-CoV-2 is crucial for viral replication and presents an attractive target for drug development. Despite the approval of some drugs, the search for effective treatments continues.

Antiviral screening of natural, anti-inflammatory compound library against African swine fever virus.

Background: African swine fever virus (ASFV) is a major threat to pig production and the lack of effective vaccines underscores the need to develop robust antiviral countermeasures. Pathologically, a significant elevation in pro-inflammatory cytokine production is associated with ASFV infection in pigs and there is high interest in identifying dual-acting natural compounds that exhibit antiviral and anti-inflammatory activities.

Methods: Using the laboratory-adapted ASFV BA71V strain, we screened a library of 297 natural, anti-inflammatory compounds to identify promising candidates that protected Vero cells against virus-induced cytopathic effect (CPE).

Discovery of new antiviral agents through artificial intelligence: In vitro and in vivo results.

In this research, we employed a deep reinforcement learning (RL)-based molecule design platform to generate a diverse set of compounds targeting the neuraminidase (NA) of influenza A and B viruses. A total of 60,291 compounds were generated, of which 86.5 % displayed superior physicochemical properties compared to oseltamivir.

Glycerol Monolaurate Inhibits Wild-Type African Swine Fever Virus Infection in Porcine Macrophages.

Naturally abundant antimicrobial lipids, such as fatty acids and monoglycerides, that disrupt membrane-enveloped viruses are promising mitigants to inhibit African swine fever virus (ASFV). Among mitigant candidates in this class, glycerol monolaurate (GML) has demonstrated particularly high antiviral activity against laboratory-adapted ASFV strains. However, there is an outstanding need to further determine the effects of GML on wild-type ASFV strains, which can have different virulence levels and sensitivities to membrane-disrupting compounds as compared to laboratory-adapted strains.

Advanced virtual screening enables the discovery of a host-targeting and broad-spectrum antiviral agent.

We employed an advanced virtual screening (AVS) approach to identify potential inhibitors of human dihydroorotate dehydrogenase (DHODH), a validated target for development of broad-spectrum antivirals. We screened a library of 495118 compounds and identified 495 compounds that exhibited better binding scores than the reference ligands involved in the screening. From the top 100 compounds, we selected 28 based on their consensus docking scores and structural novelty.

Design of new chemical entities targeting both native and H275Y mutant influenza a virus by deep reinforcement learning.

Influenza virus remains a major public health challenge due to its high morbidity and mortality and seasonal surge. Although antiviral drugs against the influenza virus are widely used as a first-line defense, the virus undergoes rapid genetic changes, resulting in the emergence of drug-resistant strains. Thus, new antiviral drugs that can outwit resistant strains are of significant importance.

Antiviral activity of brequinar against African swine fever virus infection in vitro.

African swine fever virus (ASFV) is a double-stranded DNA virus that causes an acute and hemorrhagic disease in domestic swine, resulting in significant economic losses to the global porcine industry. The lack of vaccines and antiviral drugs highlights the urgent need for antiviral studies against ASFV. Here, we report that brequinar (BQR), which is a specific inhibitor of dihydroorotate dehydrogenase, robustly inhibits ASFV replication in Vero cells, as well as in porcine macrophages.

Computational Design of Gas Sensors Based on VS Monolayer.

Novel magnetic gas sensors are characterized by extremely high efficiency and low energy consumption, therefore, a search for a two-dimensional material suitable for room temperature magnetic gas sensors is a critical task for modern materials scientists. Here, we computationally discovered a novel ultrathin two-dimensional antiferromagnet VS, which, in addition to stability and remarkable electronic properties, demonstrates a great potential to be applied in magnetic gas sensing devices. Quantum-mechanical calculations within the DFT + approach show the antiferromagnetic ground state of VS, which exhibits semiconducting electronic properties with a band gap of 0.

Flavonoid Library Screening Reveals Kaempferol as a Potential Antiviral Agent Against African Swine Fever Virus.

Naturally occurring plant flavonoids are a promising class of antiviral agents to inhibit African swine fever virus (ASFV), which causes highly fatal disease in pigs and is a major threat to the swine industry. Currently known flavonoids with anti-ASFV activity demonstrate a wide range of antiviral mechanisms, which motivates exploration of new antiviral candidates within this class. The objective of this study was to determine whether other flavonoids may significantly inhibit ASFV infection .

Natural antimicrobial peptides as a source of new antiviral agents.

Current antiviral drugs are limited because of their adverse side effects and increased rate of resistance. In recent decades, much scientific effort has been invested in the discovery of new synthetic and natural compounds with promising antiviral properties. Among this new generation of compounds, antimicrobial peptides with antiviral activity have been described and are attracting attention due to their mechanism of action and biological properties.

Combination of consensus and ensemble docking strategies for the discovery of human dihydroorotate dehydrogenase inhibitors.

The inconsistencies in the performance of the virtual screening (VS) process, depending on the used software and structural conformation of the protein, is a challenging issue in the drug design and discovery field. Varying performance, especially in terms of early recognition of the potential hit compounds, negatively affects the whole process and leads to unnecessary waste of the time and resources. Appropriate application of the ensemble docking and consensus-scoring approaches can significantly increase reliability of the VS results.

A new microtubule-stabilizing agent shows potent antiviral effects against African swine fever virus with no cytotoxicity.

African swine fever virus (ASFV) is the causal agent of a fatal disease of domestic swine for which no effective antiviral drugs are available. Recently, it has been shown that microtubule-targeting agents hamper the infection cycle of different viruses. In this study, we conducted in silico screening against the colchicine binding site (CBS) of tubulin and found three new compounds with anti-ASFV activity.

Inhibition of African swine fever virus in liquid and feed by medium-chain fatty acids and glycerol monolaurate.

Background: The ongoing African swine fever virus (ASFv) epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority. It has been recently identified that feed and feed ingredients, along with drinking water, can serve as transmission vehicles and might facilitate transboundary spread of ASFv. Thus, it is important to test the antiviral activity of regulatory compatible, antiviral feed additives that might inhibit ASFv infectivity in feed.

High-throughput protein precipitation method with 96-well plate for determination of doxepin and nordoxepin in human plasma using LC-MS/MS.

The aim of this study was to establish a high-throughput and sensitive LC-MS/MS method for the determination of doxepin and its major active metabolite nordoxepin in human plasma. It has been designed for bioequivalence study for formulations containing 25 mg of doxepin. Doxepin and nordoxepin were extracted from human plasma samples by protein precipitation with acetonitrile by using protein precipitation 96-well plates.

Synthesis, Antitumor Activity, and Docking Analysis of New Pyrido[3',2':4,5]furo(thieno)[3,2-]pyrimidin-8-amines.

Continuing our research in the field of new heterocyclic compounds, herein we report on the synthesis and antitumor activity of new amino derivatives of pyrido[3',2':4,5](furo)thieno[3,2-]pyrimidines as well as of two new heterocyclic systems: furo[2-]imidazo[1,2-]pyrimidine and furo[2,3-]pyrimido[1,2-]pyrimidine. Thus, by refluxing the 8-chloro derivatives of pyrido[3',2':4,5]thieno(furo)[3,2-]pyrimidines with various amines, the relevant pyrido[3',2':4,5]thieno(furo)[3,2-]pyrimidin-8-amines were obtained. Further, the cyclization of some amines under the action of phosphorus oxychloride led to the formation of new heterorings: imidazo[1,2-]pyrimidine and pyrimido[1,2-]pyrimidine.

Protein precipitation method for determination of clobazam and N-desmethylclobazam in human plasma by LC-MS/MS.

A protein precipitation method for the determination of clobazam (CLB) and its major active metabolite N-desmethylclobazam (N-CLB) in human plasma by liquid chromatography tandem mass spectrometry (LC-MS/MS) was established. CLB and N-CLB were extracted from human plasma samples by protein precipitation with methanol. Analyte separation was done using a Phenomenex Kinetex™ Biphenyl (50 × 2.

Evidence of Crimean-Congo Haemorrhagic Fever Virus Occurrence in Ixodidae Ticks of Armenia.

Background: Crimean-Congo hemorrhagic fever (CCHF) causes serious health problems in humans. Though ticks of the genera play a significant role in the CCHF virus transmission it was also found in 31 other tick species.

Methods: Totally, 1412 ticks from 8 remote sites in Armenia during 2016 were sampled, pooled (3-5 ticks per pool) and tested for the presence of CCHFV antigen using ELISA test.

Antiviral agents against African swine fever virus.

African swine fever virus (ASFV) is a significant transboundary virus that continues to spread outside Africa in Europe and most recently to China, Vietnam and Cambodia. Pigs infected with highly virulent ASFV develop a hemorrhagic fever like illness with high lethality reaching up to 100%. There are no vaccines or antiviral drugs available for the prevention or treatment of ASFV infections.

Inhibition of African swine fever virus infection by genkwanin.

African swine fever virus (ASFV) is the causative agent of an economically important disease of pigs for which no effective vaccines or antiviral drugs are available. Recent outbreaks in EU countries and China have highlighted the critical role of antiviral research in combating this disease. We have previously shown that apigenin, a naturally occurring plant flavone, possesses significant anti-ASFV activity.

Diagnosis of Vitreoretinal Aspergillosis with Transvitreal Retinochoroidal Biopsy.

Diagnosing culture-proven endophthalmitis is complicated by the insufficient yield of intraocular samples and the variety of etiologies which mimic true endophthalmitis. In cases of impending vision loss where vitreous biopsy cannot provide a definitive diagnosis, transvitreal retinochoroidal biopsy can be an effective next step. Our case is a 48-year-old male with B-cell acute lymphoblastic leukemia that presented with counting fingers vision, redness, and tearing of the left eye.

Genistein inhibits African swine fever virus replication in vitro by disrupting viral DNA synthesis.

African swine fever virus (ASFV) is the causal agent of a highly-contagious and fatal disease of domestic pigs, leading to serious socio-economic consequences in affected countries. Once, neither an anti-viral drug nor an effective vaccines are available, studies on new anti-ASFV molecules are urgently need. Recently, it has been shown that ASFV type II topoisomerase (ASFV-topo II) is inhibited by several fluoroquinolones (bacterial DNA topoisomerase inhibitors), raising the idea that this viral enzyme can be a potential target for drug development against ASFV.

New Tungsten Borides, Their Stability and Outstanding Mechanical Properties.

We predict new tungsten borides, some of which are promising hard materials that are expected to be stable in a wide range of conditions, according to the computed composition-temperature phase diagram. New boron-rich compound WB is predicted to be superhard, with a Vickers hardness of 45 GPa, to possess high fracture toughness of ∼4 MPa·m, and to be thermodynamically stable in a wide range of temperatures at ambient pressure. Temperature dependences of the mechanical properties of the boron-richest WB and WB phases were studied using quasiharmonic and anharmonic approximations.

Intracellular African swine fever virus DNA remains unmethylated in infected Vero cells.

Aim: Sequence-specific CpG methylation of eukaryotic promoters is an important epigenetic signal for long-term gene silencing. We have now studied the methylation status of African swine fever virus (ASFV) DNA at various times after infection of Vero cells in culture.

Methods & Results: ASFV DNA was detectable throughout the infection cycle and was found unmethylated in productively infected Vero cells as documented by bisulfite sequencing of 13 viral DNA segments.