Abdo A. Elfiky

Background: The lack of anti-COVID-19 treatment to date warrants urgent research into potential therapeutic targets. Virtual drug screening techniques enable the identification of novel compounds that target the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Main Protease (Mpro). Objective: The binding of the halogenated compounds to Mpro may inhibit the replication and transcription of SARS-CoV-2 and, ultimately, stop the viral life cycle. In times of dire need for anti-COVID-19 treatment, this study lays the groundwork for further experimental research to investi-gate these compounds' efficacy and potential medical uses to treat COVID-19. Methods: New heterocyclic compounds were synthesized through the first reaction of cyclohexane-1, 3-dione (1a) or dimedone (1b) with trichloroacetonitrile (2) to give the 2,2,2-trichloroethylidene) cyclohexane-1,3-dione derivatives 3a and 3b, respectively. The latter compounds underwent a series of heterocyclization reactions to produce biologically active compounds. Results: Novel compounds, including fused thiophene, pyrimidine and pyran derivatives, were synthesized and tested against human RNA N7-MTase (hRNMT) and selected viral N7-MTases such as SARS-CoV nsp14 and Vaccinia D1-D12 complex to evaluate their specificity and their molecular modeling was also studied in the aim of producing anti-COVID-19 target molecules. Conclusion: The results showed that compounds 10a, 10b, 10c, 10e, 10f, 10g and 10h showed high % inhibitions against SARs-Covnsp 14. Whereas compounds 5a, 7a, 8b, 10a, 10b, 10c and 10i showed high inhibitions against hRNMT. This study explored the binding affinity of twenty-two halogenated compounds to the SARS-CoV-2 MPro and discovered fifteen compounds with higher binding affinity than Nelfinavir, of which three showed remarkable results. c-Met kinase inhibitions of 10a, 10f, 10g and 10h showed that all compounds exhibited higher inhibitions than the reference Foretinib. © 2023 Bentham Science Publishers.

Background: Human papillomavirus (HPV) represents an etiological factor for many cancer types, especially cervical cancer. Its oncoprotein E6 sheds drug designers who aim to stop its cellular protein associations, such as p53 and E6AP. Recently, it was discovered that the host-cell chaperone glucose-regulated protein 78 (GRP78) plays a crucial function in HPV infectivity by association with the viral E6 and E7 proteins. Therefore, we aimed to test small molecules inhibitor that could contradict the association between E6 and cellular factors E6AP, GRP78, and p53. Methods: In this study, molecular docking protocol was elaborated to test 115 small molecule compounds against the three binding sites of HPV E6 to the host-cell proteins; E6AP, p53, and GRP78. After that, molecular dynamics simulation and free energy calculations were performed on the best three complexes. Results: The results reveal the potency of 18 compounds against the HPV E6 at different binding sites, which give lower free energies than paclitaxel (positive control). The best two compounds, hypericin, and anabsinthin, could bind effectively and stably during the 100 ns MD simulation period to HPV E6. The calculated average free energies for hypericin and anabsinthin are −18.76 and −14.40 kcal/mol, respectively. They formed stable complexes with the three binding sites by forming hydrophobic contacts. The key residues that stabilize the two ligands in HPV E6 binding sites are V31, Y32, V62, and Y70 (E6AP), P13, C16, T22, I23 and A46 (p53), and M1, V31, L50, L67, and Q107 (GRP78). Conclusions: The best two compounds, hypericin, and anabsinthin, are potential candidates against HPV E6 at the host-cell factors binding sites, hence could block the oncoprotein activity of E6 in infected cells. Further experimental validation is yet to be performed and suggested as future work. Communicated by Ramaswamy H. Sarma. © 2023 Informa UK Limited, trading as Taylor & Francis Group.

Objectives: Mucormycosis has been reported associated with SARS-CoV-2 infections during the last year. The viral RNA-dependent RNA polymerase (RdRp) was proved to be a critical protein target in viral and fungal pathogens. The human inosine monophosphate dehydrogenase (IMPDH) is an evolved antiviral and antimicrobial therapeutic target. The aim is to triple-hit the viral and fungal RdRps and the human IMPDH. Methods: In the current study, molecular docking combined with molecular dynamics simulation (MDS) is utilized to test nucleotide inhibitors against the RdRps of SARS-CoV-2 and Rhizopus oryzae (the main causing agent of mucormycosis) RdRp. Additionally, the same inhibitors targeted the human Inosine monophosphate dehydrogenase (IMPDH). Results: The results reveal a comparable binding affinity of four nucleotide derivatives compared to remdesivir and sofosbuvir against both IMPDH and the RdRps of SARS-CoV-2 and Rhizopus oryzae. The binding affinities are calculated using different conformations of the RdRps after 100 ns MDS and trajectories clustering. Conclusions: The current study suggests the triple inhibition potential of four nucleotide inhibitors against SARS-CoV-2 & R. oryzae RdRps and the human IMPDH, while experimental validation is yet to be performed. © 2023

Abstract: Coronavirus diseases 2019 (COVID-19) are seriously affecting human health all over the world. Nucleotide inhibitors have promising results in terms of its efficacy against different viral polymerases. In this study, detailed molecular docking and dynamics simulations are used to evaluate the binding affinity of a clinically approved drug, sofosbuvir, with the solved structure of the viral protein RNA-dependent RNA polymerase (RdRp) and compare it to the clinically approved drug, Remdesivir. These drugs are docked onto the three-dimensional structure of the nsp12 protein of SARS-CoV-2, which controls the polymerization process. Hence, it is considered one of the primary therapeutic targets for coronaviruses. Sofosbuvir is a drug that is currently used for HCV treatment; therefore, HCV RdRp is used as a positive control protein target. The protein dynamics are simulated for 100 ns, while the binding is tested during different dynamics states of the SARS-CoV-2 RdRp. Additionally, the drug-protein complexes are further simulated for 20 ns to explore the binding mechanism. The interaction of SARS-CoV-2 RdRp as a target with the active form of sofosbuvir as a ligand demonstrates binding effectiveness. One of the FDA-approved antiviral drugs, such as sofosbuvir, can help us in this mission, aiming to limit the danger of COVID-19. Sofosbuvir was found to bind nsp12 with comparable binding energies to that of Remdesivir, which has been reported for its potential against COVID-19 RdRp and is currently approved by the FDA. Graphic abstract: [Figure not available: see fulltext.]. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.

During the emerging second wave of COVID-19 in India in the previous two months, of rare fungal infections the Mucormycosis, was reported and alarmed the possible epidemic of this fungal disease in COVID-19 patients and recovered persons2. The total number of reported Mucormycosis infections is high in India as compared to the global reports8. The limited oxygen supplies and the rising of the country's death toll during COVID-19 with the highest record of daily new cases attributed to many reasons including the new variant B.1.617 (delta variant) reported in India and 78 other countries10,11 © 2022 World Research Association. All rights reserved.

Human coronavirus SARS-CoV-2 is the causative agent for the COVID-19 pandemic we are encountering nowadays. With the rapid spread of the contagious virus, it is urgent to find possible therapeutics. Chitosan is a naturally occurring polymer found in animals and plants. Antiviral and antibacterial activities of chitosan were documented. In the current study, the association of chitosan with the viral spike protein was assessed utilizing computational techniques. Molecular docking, combined with molecular dynamics, was used to test the binding affinity of chitosan to SARS-CoV-2 spike protein. The results suggest excellent binding potency of the chitosan to SARS-CoV-2 spike receptor-binding domain (RBD). These results are based on the docking and the interaction dynamics. Chitosan was able to form eight contacts (H-bonds and few salt bridges) with the spike receptor-binding domain (RBD) near the angiotensin-converting enzyme 2 (ACE2) and glucose regulating protein 78 (GRP78) recognition surfaces. Thus, chitosan can be a successful candidate against COVID-19; however, the in-silico results are yet to be validated experimentally. The current data were submitted to the Egyptian Academy of Scientific Research and Technology (ASRT) patent office with the registration number of 1602/2020. © 2022, Egyptian Society for the Development of Fisheries and Human Health. All rights reserved.

The emerging outbreak of COVID-19 infection posed serious threat to human lives, claiming thousands of deaths worldwide. Both the emergence and subsequent transmission of SARS-CoV-2 underscore the urgent and critical need for the identification and development of effective preventive and therapeutic agents against COVID-19. This chapter aims to focus on promising anti-COVID-19 dietary polyphenols such as hesperidin, naringenin, Epigallocatechin gallate, and curcumin, their mechanism of action, safe dosage, toxicity, and bioavailability for future public health practices and research. Based on various computational, in vitro and in vivo pieces of evidence supporting efficacy, safety, and good bioavailability of polyphenols, this chapter demonstrates the potential of these entities for the prevention and development of therapeutics for the management of COVID-19. Although dietary polyphenols have been systematically studied from pharmacological point of view, a vast field of pr-clinical and clinical exploration still appears to be open for the research to fully validate their potential for the treatment of viral infections. © 2022 Elsevier Inc. All rights reserved.

During the past few months, mucormycosis has been associated with SARS-CoV-2 infections. Molecular docking combined with molecular dynamics simulation is utilized to test nucleotide-based inhibitors against the RdRps of SARS-CoV-2 solved structure and Rhizopus oryzae RdRp model built in silico. The results reveal a comparable binding affinity of sofosbuvir, galidesivir, ribavirin and remdesivir compared with the physiological nucleotide triphosphates against R. oryzae RdRp as well as the SARS-CoV-2 RdRp as reported before. Additionally, other compounds such as setrobuvir, YAK, IDX-184 and modified GTP compounds 2, 3 and 4 show potential calculated average binding affinities against R. oryzae RdRp. The present in silico study suggests the dual inhibition potential of the recommended drugs and compounds against SARS-CoV-2 and R. oryzae RdRps. © 2022 Future Medicine Ltd.

Finding a potent inhibitor to the pandemic SARS-CoV-2 is indispensable nowadays. Currently, in-silico methods work as expeditious investigators to screen drugs for possible repurposing or design new ones. Targeting one of the possible SARS-CoV-2 attachment and entry receptors, Glucose-regulated protein 78 (GRP78), is an approach of major interest. Recently, GRP78 was reported as a recognized representative in recognition of the latest variants of SARS-CoV-2. In this work, molecular docking and molecular dynamics simulations were performed on the host cell receptor GRP78. With its many terpenoid compounds, Chaga mushroom was tested as a potential therapeutic against the SARS-CoV-2 receptor, GRP78. Results revealed low binding energies (high affinities) toward the GRP78 substrate-binding domain β (SBDβ) of Chaga mushroom terpenoids. Even the highly specific cyclic peptide Pep42, which selectively targeted GRP78 over cancer cells in vivo, showed lower binding affinity against GRP78 SBDβ compared to the binding affinities of terpenoids. These are auspicious results that need to be tested experimentally. Intriguingly, terpenoids work as a double sword as they can be used to interfere with VUI 202,012/01, 501.V2, and B.1.1.248 variants of SARS-CoV-2 spike recognition. © 2022 Elsevier Ltd

Over a span of two years ago, since the emergence of the first case of the novel coronavirus (SARS-CoV-2) in China, the pandemic has crossed borders causing serious health emergencies, immense economic crisis and impacting the daily life worldwide. Despite the discovery of numerous forms of precautionary vaccines along with other recently approved orally available drugs, yet effective antiviral therapeutics are necessarily needed to hunt this virus and its variants. Historically, naturally occurring chemicals have always been considered the primary source of beneficial medications. Considering the SARS-CoV-2 main protease (Mpro) as the duplicate key element of the viral cycle and its main target, in this paper, an extensive virtual screening for a focused chemical library of 15 batzelladine marine alkaloids, was virtually examined against SARS-CoV-2 main protease (Mpro) using an integrated set of modern computational tools including molecular docking (MDock), molecule dynamic (MD) simulations and structure-activity relationships (SARs) as well. The molecular docking predictions had disclosed four promising compounds including batzelladines H–I (8–9) and batzelladines F-G (6–7), respectively according to their prominent ligand-protein energy scores and relevant binding affinities with the (Mpro) pocket residues. The best two chemical hits, batzelladines H–I (8–9) were further investigated thermodynamically though studying their MD simulations at 100 ns, where they showed excellent stability within the accommodated (Mpro) pocket. Moreover, SARs studies imply the crucial roles of the fused tricyclic guanidinic moieties, its degree of unsaturation, position of the N–OH functionality and the length of the side chain as a spacer linking between two active sites, which disclosed fundamental structural and pharmacophoric features for efficient protein-ligand interaction. Such interesting findings are greatly highlighting further in vitro/vivo examinations regarding those marine natural products (MNPs) and their synthetic equivalents as promising antivirals. © 2022 Elsevier Ltd

According to the World Health Organization (WHO), SARS-CoV-2 is responsible for more than 5 M deaths and is reported in 223 countries infecting 250+ M people. Despite the current vaccination momentum, thousands of people die every day by COVID-19. Suggesting possible blockers of the viral RNA-dependent RNA polymerase is highly needed for potential effective therapeutics against SARS-CoV-2. This study utilizes combined molecular dynamics simulation and molecular docking to test novel guanosine derivatives against SARS-CoV-2 RdRp. Results reveal the binding potency of nineteen guanosine derivatives against SARS-CoV-2 solved structures. The bulky moieties (hydroxyl or fluorated phenyl moieties) added to the 2′ position of the ribose ring positively impacted the binding affinity to RdRp. The current in silico study represents a one-step-ahead for suggesting new possible blockers of SARS-CoV-2 RdRp that are yet to be verified in the wet lab. It offers new potential binders or blockers of RdRp that bind to the protein active site tighter than remdesivir. The latter was approved by the food and drug administration (FDA) for emergency use against COVID-19 last year. © The Royal Society of Chemistry.

SARS-CoV-2, a rapidly spreading new strain of human coronavirus, has affected almost all the countries around the world. The lack of specific drugs against SARS-CoV-2 is a significant hurdle towards the successful treatment of COVID-19. Thus, there is an urgent need to boost up research for the development of effective therapeutics against COVID-19. In the current study, we investigated the efficacy of 81 medicinal plant-based bioactive compounds against SARS-CoV-2 Mpro by using various in silico techniques. The interaction affinities of polyphenolic compounds towards SARS-CoV-2 Mpro was assessed via intramolecular (by Quantum Mechanic), intermolecular (by Molecular Docking), and spatial (by Molecular Dynamic) simulations. Our obtained result demonstrate that Hesperidin, rutin, diosmin, and apiin are most effective compounds agents against SARS-CoV-2 Mpro as compared to Nelfinavir (positive control). This study will hopefully pave a way for advanced experimental research to evaluate the in vitro and in vivo efficacy of these compounds for the treatment of COVID-19. © 2022 Elsevier Ltd

SARS-CoV-2 represents the causative agent of the current pandemic (COVID-19). The drug repurposing technique is used to search for possible drugs that can bind to SARS-CoV-2 proteins and inhibit viral replication. In this study, the FDA-approved antiplatelets are tested against the main protease and spike proteins of SARS-CoV-2 using in silico methods. Molecular docking and molecular dynamics simulation are used in the current study. The results suggest the effectiveness of vorapaxar, ticagrelor, cilostazol, cangrelor, and prasugrel in binding the main protease (Mpro) of SARS-CoV-2. At the same time, vorapaxar, ticagrelor, and cilostazol are the best binders of the spike protein. Therefore, these compounds could be successful candidates against COVID-19 that need to be tested experimentally. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Different SARS-CoV-2 new variants emerged and spread during the past few months, sparking infections and death counts. The new variant B.1.617 (delta variant) sparked in India in the past few months, causing the highest records. The B.1.617 variant of SARS-CoV-2 has the double mutations E484Q and L452R on its spike Receptor Binding Domain (RBD). The first mutation is like the reported South African and the Brazilian variants (501.V2 and B.1.1.248). This mutation lies in the region C480-C488, which we predicted before to be recognized by the host-cell receptor; Glucose Regulated Protein 78 (GRP78). In the current study, we test the binding affinity of the host-cell receptor GRP78 to the delta variant spike RBD using molecular docking and molecular dynamics simulations of up to 100 ns. Additionally, the ACE2-RBD is tested by protein–protein docking. The results reveal equal average binding affinities of the GRP78 against wildtype and delta variant spikes. This supports our previous predictions of the contribution of GRP78 in SARS-CoV-2 spike recognition as an auxiliary route for entry. © 2022, The Author(s).

A novel series of bis-[1,3,4]thiadiazolimines, and bis-thiazolimines, with alkyl linker, were synthesized through general routes from cyclization of 1,1′-(hexane-1,6-diyl)bis(3-phenylthiourea) and hydrazonoyl halides or α-haloketones, respectively. Docking studies were applied to test the binding affinity of the synthesized products against the Mpro of SARS-CoV-2. The best compound, 5h, has average binding energy (−7.50 ± 0.58 kcal/mol) better than that of the positive controls O6K and N3 (−7.36 ± 0.34 and −6.36 ± 0.31 kcal/mol). Additionally, the docking poses (H-bonds and hydrophobic contacts) of the tested compounds against the Mpro using the PLIP web server were analyzed. © 2022 by the authors.

BACKGROUND: Characterization of normal and malignant breast tissues using X-ray scattering techniques has shown promising results and applications. OBJECTIVE: To examine possibility of characterizing normal and malignant breast tissues using the scattered photon distribution of polyenergetic beams of 30 kV X-rays. METHODS: A Monte Carlo simulation is upgraded so that it is capable of simulating input mammographic X-ray spectra from different target-filter combinations, tracing photon transport, and producing the distribution of scattered photons. The target-filter combinations include Mo-Mo, Mo-Al, Mo-Rh, Rh-Rh, Rh-Al, W-Rh, and W-Al. Analysis of obtained scattered photon distribution is carried out by comparing the ratio of count under the peak in the momentum transfer region from 0 to 1.55 nm-1, to that in the region from 1.6 to 9.1 nm-1 (covering the regions of scattering from fat and soft tissue, respectively) for breast samples with different percentages of normal tissue (0-100%). RESULTS: Mo-Mo target-filter combination shows a high linear dependence of the count under peak ratio on the percentage of normal tissue in breast samples (R2 = 0.9513). Despite slightly less linear than Mo-Mo, target-filter combinations other than Rh-Rh, W-Rh, and W-Al produce high linear responses (R2 > 0.9) CONCLUSION: Mo-Mo target-filter combination would probably be the most relevant in characterizing normal and malignant breast tissues from their scattered photon distribution. © 2022 - IOS Press. All rights reserved.

Researchers are focused on discovering compounds that can interfere with the COVID-19 life cycle. One of the important non-structural proteins is endoribonuclease since it is responsible for processing viral RNA to evade detection of the host defense system. This work investigates a hierarchical structure-based virtual screening approach targeting NSP15. Different filtering approaches to predict the interactions of the compounds have been included in this study. Using a deep learning technique, we screened 823,821 compounds from five different databases (ZINC15, NCI, Drug Bank, Maybridge, and NCI Diversity set III). Subsequently, two docking protocols (extra precision and induced fit) were used to assess the binding affinity of the compounds, followed by molecular dynamic simulation supported by the MM-GBSA free binding energy. Interestingly, one compound (ZINC000104379474) from the ZINC15 database has been found to have a good binding affinity of − 7.68 kcal/Mol. The VERO-E6 cell line was used to investigate its therapeutic effect in vitro. Half-maximal cytotoxic concentration and Inhibitory concentration 50 were determined to be 0.9 mg/ml and 0.01 mg/ml, respectively; therefore, the selectivity index is 90. In conclusion, ZINC000104379474 was shown to be a good hit for targeting the virus that needs further investigations in vivo to be a drug candidate. © 2022, The Author(s).