Databases, DrugBank, and virtual screening platforms for therapeutic development

The upsurge of the severe acute respiratory syndrome-Coronavirus-2 (SARS-CoV-2) has turned into a global health disaster. Many remodeled medications were suggested for treatment in the early stages of this pandemic, but these dosages afterward came across with distinct offshoots. Thus, these consequences compelled the scientists to develop new drugs using various antiviral, antiinflammatory, antibacterial, and phytochemical compounds. A handful of drugs have been scrutinized in silico, in vitro, plus through human trials such as anti-SARS-CoV-2 agents and made available as various databases by various scientific communities. The SARS-CoV-2 pandemic databases are designed to allay difficulties associated with this scenario. Some of the popular databases are GESS (global evaluation of SARS-CoV-2/HCoV-19 sequences) which gives a thorough study of data based on tenfold of thousands of complete coverage and quality of SARS-CoV-2 genomes, CORona Drug InTERactions (CORDITE) database for SARS-CoV-2 which profoundly combines the understanding of potential drugs and make it available for scientists and medicos. SARSCOVIDB set one’s sights to merge all differential gene expression data, at mRNA and protein levels, helping to accelerate analysis and research on the molecular impact of covid-19. This chapter aims to provide a piece of complete information about the SARS-CoV-2 virus databases, potentially available drugs, and virtual screening methods. And also provides a different webserver to reach out for information related to the COVID-19 pandemic and its future.


Limitations
This site is based on the PubMed database, and articles in different journals that are not listed on this database might not be accessible. Another drawback is the lack of a keen searching characteristic for the content of this site .

Gess
This hub enables the user to forage and "download single nucleotide variants" (SNVs) at any single or multiple "SARS-CoV-2" genomic locations, or in a selected genomic site or protein, or country of interest. GESS shows geographical distributions of SNVs around the world and in all US states and shows time-dependent blue-prints for SNV occurrences that reflect the evolution of "SARS-CoV-2 genomes" (Mavian et al., 2020). The GESS database is designed using the R language. The complete genome sequences of SARS-CoV-2 were recorded from the GISAID database and processed as a document (Ugurel et al., 2020).

CORDITE
CORDITE is presently the most systemized drug interactions database for SARS-CoV-2, and consequently, it provides the possibility to boost up research in the realms of virology and drug design. In addition, original studies also give an option for reviews and comments in the database. The usage of moderators aids the manual systemization of details from the articles and preprints could be obtained through the web interface or the open API. Users can immediately get access through the journals, interactions, therapeutics, targets, metaanalysis, and clinical trials. This access may offer easier integration for a future perspective that may need systematic data (Martin et al., 2020).
General Information Stored in the SARSCOVIDB, includes: • SARSCOVIDB ID reference: documentation of the entry in the SARSCOVIDB. • Gene name: official gene name for each stored entry. • Protein name: official protein name for each stored entry.
• Host/sample: host model used to generate SARS-COV-2 infection data.
• Sample: description of the sample, such as if it is a human biological sample (blood, urine, serum, etc.) or experimental sample (cell line or animal tissue thjnnbd0faZISOhg3256FG, h6ested in vitro). • Virus reference: SARS-CoV-2 strain reference or geographic origin of the SARS-CoV 1 2 viral isolate or clinical sample. • Methods: methods used to measure gene expression at the level of RNA and/or protein after SARS-CoV-2 infection. • Expression: indicates the identified gene expression status (up and/or downregulated) in response to SARS-CoV-2 infection. • Article: article title used as a data source.
• DOI: direct link to the original reference where the data came from.
• The type of sample indicates if the data were generated using clinical or experimental samples (da Rosa et al., 2021).

DockCoV2
This database employs the most commonly used drug databases to provide a computational representation of molecular docking in order to speed up the process of searching specific drugs (Kim et al., 2019). Through this database, users can obtain potential drug candidates against SARS-CoV-2 through the docking scores of candidate drugs with important drug-relevant data DockCoV2 focuses on predicting 2285 Food and Drug Administration (FDA)-approved and 1478 Taiwan NHI-approved drugs targeting seven proteins relating to the mechanism of entry of virus and its replication .

H2V
H2V is the first-ever database of "human proteins and genes" that answer to SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome-Coronavirus (MERS-CoV) infection. The database enables us to study how the human body responds to viral infections. To facilitate speedy drug search, H2V provides a search engine to find drugs against the given protein based on the UniProt accession number. Based on the search, potential drugs and their DrugBank identifiers will then be displayed on the lower part of the same page. To help users visualize the dynamic changes occurring in all genes/proteins over time post-infection, H2V provides a utility called "Data animation" (Wan et al., 2020;Xu et al., 2020;Zhou, Yang, et al., 2020). 14.6 Severe acute respiratory syndrome-Coronavirus-2 three-dimensional • SARS-CoV-2 three-dimensional is a complete database providing important data for drugs against COVID-19. • It offers collective computational and experimental three-dimensional conformations data on a single platform. • "The database comprises of protomers, homo-oligomers, hetero-oligomers, and transmem-brane modeled proteins, which also includes ligands and cofactors. It provides the prediction of allosteric and small ligand-binding sites prediction. SARS-CoV-2 three-dimensional provides proteinÀprotein interactions between SARS-CoV-2 and human proteins. Á It also includes proteinÀligand docking and saturation mutagenesis." • The database is frequently updated with new mutational findings and a series of genomic sequence and structure-based approaches are exploited to analyze the influences of mutations (Alsulami et al., 2021).

Coronavirus disease-2019 CG
COVID-19 CG is an efficient, cooperating, powerful, and fully scalable online application that tracks SARS-CoV-2 single-nucleotide variants (SNVs), lineages, and clades without subsampling. COVID-19 CG is free, open access that allows users to analyze according to their date and site of interest. Users can also select and compare trends in SARS-CoV-2 lineage, clade, or SNV frequency across multiple locations as it will start using case studies. COVID-19 CG provides features that are complement other current public browsers and were intended to allow these specific user groups: Vaccine and drug developers can inform the design and trials for their vaccine, antibody, or small molecule by using COVID-19 CG to rapidly classify all the variants in their SARS-CoV-2 target protein or antigen, together with the rate of each variant in their geographical site of interest. Researchers can use COVID-19 CG to create theories and determine whether the variations present in the location of therapeutic application may influence their specific antigen .
5. Sequence data incorporates: (a) the entire variable domain sequence for the antibody/ nanobody, importance to the CDR3 regions, and (b) V and J gene germline projects. 6. Links to any accessible data involving the antibody/nanobody. 7. A homologous model of the antibody/nanobody. 8. References to the prime literature on the antibody/nanobody. 9. Timestamps to show when the antibody/nanobody was added or updated lately. 10. Steps were taken to follow up on access (Raybould et al., 2021).

Coronavirus-GLUE
CoV-GLUE (http://cov-glue.cvr.gla.ac.uk/) is an online application free for the public for tracking and studying variation within SARS-CoV-2 gene sequences, allowing to fetch data from EpiCoV (Shu & McCauley, 2017). Its first objective is to track the chief elements of variation as they occur in outbreaks, associated with sampling data. Second, enables users to propose their own consensus data for assessment and obtain an interactive report describing genomic variability. CoV-GLUE upholds a searchable database of amino-acid classification variations within all 26 of the viral proteins, as proposed on NCBI RefSeq NC_045512. CoV-GLUE presently shows 8778 amino acid substitutes detected in outbreak sequences from EpiCoV. Besides this, CoV-GLUE also provides an online site for each variation, with a table of sequences displaying them, which may be filtered by categories containing international region, country, date and time of collection, and phylogenetic ancestry (Singer et al., 2020).

CoV2ID
The database gives a detailed web page for individual oligonucleotides and a search engine to access tables with numeric data and several sequence arrangements. The "CoV2ID database presently contains 145 oligonucleotides from 21 protocols: 64 PCR primers, 57 LAMP primers, 20 probes, and four target generation oligonucleotides. The oligonucleotides are in the ORF1ab, S, ORF3a, E, M, and N genes." The database gives access for searching, filtering, and downloading data from the different oligonucleotides allotted according to the SARS-CoV-2 reference gene sequences. For individual oligonucleotide, it finds information of the sequence, type of method used first, site in the reference genome, etc. The database shows which oligonucleotide binds to which region of the SARS-CoV-2 using different procedures (Ciobotaru et al., 1979). 14.11 ZINC An online tool from the ZINC database, called "ZINC-Pharmer" is used for pharmacophore-based screening of drugs. The 3D-conformation of the Mpro of COVID-19 and "SDF" extension file of inhibitor N3 are uploaded into the ZINC-Pharmer to generate pharmacophore structures of the ligand within the range of receptors. This type of screening is significant for the documentation of appropriate inhibitors against the target, the novel drug-like compounds are predicted and facilitated further (Koes & Camacho, 2012).

VIStEDD
The change and development for each protein were combined into VIStEDD. It has been designed for viruses that may come up in the future. Within the SARS-CoV-2 page, a list of each of the 24 proteins, where each protein can be clicked to fetch information. Each protein has an individual link, a rotational video of protein, characteristic of each protein, a tool to buy a three-dimensional print of the protein, the amino acid program from molecular dynamics simulations (MDS), and the table of data for each amino acid in protein (Gupta et al., 2020). 14.13 SMART "SMART can be used in two different modes: normal or genomic. The main difference is in the underlying protein database used. In Normal SMART, Swiss-Prot, SP-TrEMBL and stable Ensembl proteomes are used. In Genomic SMART, only the proteomes of completely sequenced genomes are used; Ensembl for metazoans and Swiss-Prot for the rest." The complete list of genomes in Genomic SMART is available at http://smart.emblheidelberg.de/. The protein database in Normal SMART has significant redundancy, even though identical proteins are removed. If you use SMART to explore domain architectures or want to find exact domain counts in various genomes, consider switching to Genomic mode. The numbers in the domain annotation pages will be more accurate, and there will not be many protein fragments corresponding to the same gene in the architecture query results (Letunic & Bork, 2018). 14.14 Immune epitope database The Immune Epitope Database (IEDB) is a freely available resource funded by NIAID. It catalogs experimental data on antibody and T cell epitopes studied in humans, nonhuman primates, and other animal species in the context of infectious disease, allergy, autoimmunity, and transplantation. The IEDB also hosts tools to assist in the prediction and analysis of epitopes (Vita et al., 2019).

SWISS-MODEL
The main objective of the SWISS-MODEL database is to give access to an updated set of interpreted three-dimensional protein models generated by automatic homologous modeling for relative model organisms and new structural information for all genomic sequences in UniProtKB. Daily updates confirm that reporting the targets are complete, that models are designed using sequence and template structure databases. Enables users to assess the superiority of the models using the modern QMEAN results. If a sequence has not been modeled, allows users to design models interactively through the SWISS-MODEL database (Waterhouse et al., 2018). 14.16 Iterative threading assembly refinement Iterative Threading ASSEmbly Refinement (I-TASSER) is a stratified approach for predicting protein structures and for structure-based function annotation. Firstly, the structural templates from the PDB are identified using LOMETS multiple threading approach, with full-length atomic models being designed from iterative template-based fragment assembly simulations. Functional views of the target are then gained using re-threading the three-dimensional models through BioLiP, a protein function database. Currently, the server is actively developed to give the exact protein structure and predictions using stateof-the-art systems (Yang & Zhang, 2015).

DrugBank
DrugBank is an online site that offers free-to-access for the public, containing information on potential drugs and their targets. As both a bioinformatics and a cheminformatics resource, combine detailed information of drug is needed with complete and specific drug targets. DrugBank hub is widely used by the drug industry, pharmacists, chemists, physicians, students, researchers, and the public. Because of its wide scope, complete referencing, and detailed descriptions of data, DrugBank is allowing chief progressions across the medicine industry (Wishart et al., 2018). 14.17 Drugs against severe acute respiratory syndrome-Coronavirus-2

DrugBank
The drug-repurposing (techniques) has been used to treat a variety of infectious diseases, including the COVID-19 pandemic (Goyal et al., 2021). The workflow for drug repurposing differs from that of conventional drug production. There are fewer steps and various parameters to follow in drug repurposing: compound detection, acquisition, production, and postmarket safety monitoring by the FDA (Dotolo et al., 2021). Computational drug repositioning methods used on COVID-19 are divided into three categories: (i) network-based models, (ii) structure-based approaches, and (iii) machine/deep learning methods (Usha et al., 2022).

Drug repurposing for Coronavirus disease-2019 available in DrugBank
The tried and tested drug discovery outlook entails many years of careful research and development on deadline for a large investment that cannot be validated for the current universal infection. To some extent, the world calls for a quick and profitable approach to suppressing and controlling viral infection (Usha et al., 2020). It is possible to identify lead drug-like compounds for COVID-19 using computational screening approaches and by selecting appropriate chemical space. Many factors influence the severity of a viral infection, including intrinsic pathogenicity, mortality rate, and basic reproduction number . The authors have tabulated the drugs repurposed for COVID-19 available in the DrugBank (Murugan et al., 2020) (Table 14.2).
14.18 Advantages and disadvantages

Ritonavir/lopinavir
It is a nucleoside analog and protease inhibitor combination used to treat human immunodeficiency virus (HIV) type 1 (Osborne et al., 2020). As a result, "multiple trials in COVID-19 are currently underway to determine whether LPVr is an effective treatment, including the worldwide RECOVERY trial and the World Health Organization's (WHO) SOLIDARITY trial" (https://www.who.int/emergencies/diseases/novel-coronavirus-2019/global-research-on-novel-coronavirus-2019-ncov/solidarity-clinical-trial-for-covid-19-treatments). Importantly, "LPVr is a cytochrome P450 3A4 inhibitor, it cannot be used with other medicines that are cytochrome P450 3A4 substrates, such as chloroquine, which can cause QT prolongation" (Naksuk et al., 2020). Statistics were generated for a variety of endpoints, including the risk of death, the "risk and duration of invasive mechanical ventilation, the risk of non-invasive ventilation, and the requirement for oxygen" . One of the most critical risks is QT interval prolongation, which increases the risk of unexpected cardiac death (Giudicessi et al., 2020). "Patients infected with COVID-19 are already susceptible to developing cardiac arrhythmias due to the virus's effects on metabolic dysfunction, myocardial inflammation, and the sympathetic nervous system" (Guzik et al., 2020).

Chloroquine
The use of antimalarial drugs like chloroquine (CQ) and hydroxychloroquine (HCQ) for the treatment of SARS-CoV-2 has created a lot of flutters . In February 2020, an editorial published by a French group, CQ and HCQ were proposed for use against SARS-CoV-2 (Colson et al., 2020). On March 20, 2020, Chinese researchers published a concise report emphasizing the superiority of HCQ over CQ as a prophylactic drug (Zhou, Dai, et al., 2020). The advantage of HCQ over CQ is its safety during pregnancy (Shah et al., 2020). As a result, if proven to be beneficial, HCQ could be used as a COVID-19 prophylactic drug. Usage of CQ has been associated with a variety of issues, such as the occurrence of long-term musculoskeletal symptoms in patients treated with CQ compared to placebo in a clinical trial, a variety of cardiovascular side effects including QT prolongation, and other unknown adverse reactions due to narrow safety margin (Martin et al., 2020). Another major issue is the toxicity of these drugs (Roques et al., 2018). If a drug is used without concrete scientific evidence, it causes mass hysteria and        deprives the legitimate population, such as patients with lupus and rheumatoid arthritis, off the use of these drugs (American College of Rheumatology et al., 2020). In the future, if ongoing clinical trials successfully exhibit prophylactic efficacy in CQ and HCQ targeted prophylaxis may be preferred over mass prophylaxis (Martin & Vinetz, 2018).

Darunavir
In COVID-19 patients, some retrospective studies suggested a potentially beneficial effect of HIV protease inhibitors such as Darunavir in combination with Lopinavir. "Although HCQ, azithromycin, and ritonavir/darunavir (RD) generally well undergo, all three are correlated with a high risk of QTc prolongation and cardiac arrhythmias (Moschini et al., 2021). After several trials, the QTc interval gradually increased from 438 Ms (421À454) on day 0 to 448 Ms (429À483) on day 3 and 452 Ms (430À490) on day 7 (baseline vs day 3, p 5 0.001; baseline vs day 7, p 5 0.001; day 3 vs day 7, p 5 0.001)." There are several limitations. For starters, the sample size was small. Second, the study population was made up of two consecutive series of patients with different characteristics, making comparisons between groups impossible. Furthermore, the study lacked a control group of patients who received only HCQ. Finally, higher risk subjects may have been underrepresented in the sample because individuals with prolonged QTc intervals at baseline were excluded, as recommended by international guidelines (Moschini et al., 2021).

Galidesivir
Galidesivir is an adenosine analog being studied for use against the Zaire Ebolavirus (Tchesnokov et al., 2019). Galidesivir was effective in increasing survival rates from infections caused by various pathogens, including Ebola, Marburg, Yellow Fever, and Zika viruses, in animal studies. It demonstrated broad-spectrum antiviral activity in vitro against a variety of negative and positive-sense RNA viruses (Westover et al., 2018), Adding Galidesivir to the SARS-CoV-2 cell culture may inhibit its growth. Furthermore, clinical trials have shown that this drug is safe and well-tolerated in both the intramuscular (IM) or intravenous (IV) injection and oral routes (Julander et al., 2021).

Favipiravir
Favipiravir, a purine analog, and potent RdRp inhibitor approved for influenza treatment are also being considered for COVID-19 treatment . It has been used to treat life-threatening infections such as Ebola, Lassa fever, and rabies, and its therapeutic usefulness in these diseases has been established (Mohamed AA et al., 2020). Favipiravir is a promising COVID-19 treatment that may reduce hospitalization and the need for mechanical ventilation (Hassanipur et al., 2021).

Umifenovir
Earlier clinical and basic research found that Umifenovir could reduce SARS virus replication in vitro . The use of Umifenovir for COVID-19 is still unknown . Reportedly, there is no antiviral treatment for this novel disease, it is critical to assess the efficacy and safety of Umifenovir in COVID-19 (Lian et al., 2020). It has a broad-spectrum antiviral agent, has been proposed as a potential COVID-19 treatment . Umifenovir was not found to shorten the duration of SARS-CoV-2 negativity or improve prognosis in non-ICU patients after three different studies (Huang et al., 2021).

Human interferon beta
Type 1 interferons, particularly IFN-beta, have been identified as potential leading therapeutics for severe COVID-19 and are currently being evaluated in the REMAP-CAP and the WHO's Solidarity Trial (Jalkanen et al., 2020). In phase II clinical trial, combination treatments with IFN-beta, lopinavir-ritonavir, and ribavirin demonstrated that the arm containing IFN-beta was superior in eliminating the virus from nasopharyngeal swabs (Cheung et al., 2020). Critically ill COVID-19 patients with elevated levels of plasma cytokines (particularly IL-6) exhibit immune exhaustion and poor IFN responses (Blanco-Melo et al., 2020). Even in such cases, IFN-beta would most likely benefit these patients because it is the most potent antiviral and antiinflammatory agent of all interferons. It can induce the desired immune boost while also downregulating IL-6 and IL-8 (Laver et al., 2008) and inhibit neutrophil extravasation into the lungs (Kiss et al., 2007).

TMC-310911
It is a protease inhibitor that is still being studied in clinical experiments to cure HIV infection. It has exhibited in vitro activity against HIV strains that have developed resistance to other protease inhibitors. SARS-CoV main protease (SARS) is being targeted by researchers to investigate their possible mode of inhibition (Soremekun et al., 2021).

Methylprednisolone
Corticosteroid therapy is not recommended for routine usage in cases of viral pneumonia due to its potential damage effects on the lungs (Russell et al., 2020). GLUCOCOVID is a randomized, open-label, controlled, two-arm, parallel-group trial being conducted in five Spanish hospitals (Hospital Universitario Mar-qués de Valdecilla, Hospital Universitario Río Hortega, Hospital El Bierzo, Hospital Laredo, and Hospital Sierrallana). The study's goal was to determine the efficacy of combining MP with standard therapy in patients with moderate to severe cancer. It is an abbreviation for COVID-19 (Corral-Gudino et al., 2021).

Bevacizumab
It is a humanized anti-VEGF monoclonal antibody used in treating patients suffering from severe COVID-19. The visible effect of bevacizumab on oxygenation was clearly improved after a 24-hour of treatment. This suggests that the clinical benefits of bevacizumab treatment occur at an early stage. In comparison to the control group, a significantly greater number of patients improved their 28-day oxygen-support status (control, 62% vs bevacizumab, 92%) as well as the discharge rate (control, 46% vs bevacizumab, 65%). In addition, bevacizumab-treated patients had less deterioration in oxygen-support status when compared to the control group (control, 19% vs bevacizumab, 0%) (Pang et al., 2021).

Leronlimab
It (PRO 140) is a humanized IgG4, CÀC chemokine receptor type 5 (CCR5), monoclonal antibody receptor antagonist that was initially studied for the treatment of HIV, where it was shown to be effective and well-tolerated, and is now being studied for the treatment of COVID-19 (Dhody et al., 2018). COVID-19 patients are given 700 mg of Leronlimab subcutaneously once a week for 2 weeks. Macrophages, T regulatory cells, and dendritic cells all have CCR5 receptors. The binding of Leronlimab to the CCR5 receptor inhibits CCL5 competitively (Jiao et al., 2021). Because of its good safety profile in HIV patients, mechanism of action, and basic science physiology, Leronlimab was also considered as a potential treatment option for COVID-19 (Agresti et al., 2021).

Azithromycin
In a randomized study of infants, it was shown to be effective against the respiratory syncytial virus (Beigelman et al., 2015). In vitro and in a clinical setting, azithromycin had a synergistic antiviral effect against SARS-CoV-2 when combined with HCQ. The mechanisms of AZM's antiviral effect support a broad spectrum of antiviral activity. Azithromycin appears to inhibit virus entry into cells (Tran et al., 2019). Furthermore, it can boost the immune response to viruses through a variety of mechanisms. Azithromycin stimulates the production of type 1 and 3 interferons as well as virus-recognition genes such as MDA5 and RIG-I (Zeng et al., 2019). These mechanisms are universally involved in the innate response to infectious agents, including SARS-CoV-2 (Gyselinck et al., 2021).

Elbasvir
Elbasvir reacts with RdRP, proteinase, and helicase of SARS-CoV-2. Although reusing an approved drug is by far the most excellent approach to instantly develop innovative therapeutics against this novel pathogen, researchers surveyed FDA-approved antiviral medications for docking prospects with SARS-CoV-2 proteins (Balasubramaniam & Reis, 2020).

Tocilizumab
It (TCZ) is a synthetic monoclonal antibody that serves as an IL-6 receptor antagonist. It is currently used to treat rheumatoid arthritis, but this could potentially be useful in treating COVID-19 patients who really are unwell, Though the usefulness of tocilizumab in noncritically sick patients with SARS-CoV-2 is yet unclear (Gupta et al., 2020).

Ibuprofen
It is a nonsteroidal antiinflammatory medicine (NSAID) typically used as an antipyretic and analgesic. The most prescribed antipyretics are acetaminophen and ibuprofen (Bushra & Aslam, 2010). The coronavirus (COVID-19) pandemic, resulted in widespread ibuprofen supply disruptions (Abu Esba et al., 2021). However, later throughout the news, it was reported that ibuprofen must be sidestepped because it could exacerbate COVID-19 effects (Moore et al., 2020). 14.18.18 Anti-severe acute respiratory syndrome-Coronavirus-2 REGN-Coronavirus-2 It is a combination of two highly effective neutralizing antibodies (REGN10933/ Casirivimab and REGN10987/Imdevimab), targeting two separate, nonoverlapping epitopes on the Spike protein of SARS-CoV-2. This can greatly decrease virus load, loss of weight, and pneumonia side effects, which provide conclusive proof for a clinical study (Baum, Fulton, et al., 2020). People with a strong viral load at the start of the infection or

Advantages and disadvantages
Computational Approaches for Novel Therapeutic and Diagnostic Designing to Mitigate SARS-CoV-2 Infection who still haven't established an immune response have a stronger benefit (Weinreich et al., 2021).

Dexamethasone
It is a recombinant corticosteroid that suppresses the immune system across a broad range, has greater efficacy than cortisone (Theoharides & Conti, 2020). For their ability to reduce the transcription of genes of several pro-inflammatory cytokines, chemokines, and adhesion molecules, they have antiinflammatory capabilities (Sharun et al., 2020) and may be effective in combating the COVID-19-related cytokine storm (Lim & Pranata, 2020).

Bamlanivimab/Etesevimab
It is a set of anti-Spike neutralizing monoclonal antibodies produced from two distinct COVID-19 patients in North America and China, separately (Jones et al., 2020). In clinical trials, they may improve viral load reduction and reduce treatment-emergent resistance variants (Baum, Ajithdoss, et al., 2020).

Ifenprodil
In a small handful of nations, including Japan and France, it has been utilized as a cerebral vasodilator. Ifenprodil is a prototypical antagonist of the N-methyl-D-aspartate receptor (NMDAR) of the GluN2B subunit. Ifenprodil has a strong affinity for the sigma-1 and sigma-2 receptors and repurposes them for COVID-19 (Hashimoto, 2021). 14.19 Virtual screening platforms 14.19.1 Introduction of virtual screening platforms VS is a computerized process for the identification of amalgam that binds to a specific target, typically an enzyme or receptor, from a large compound library (Gimeno et al., 2019). It is typically approached hierarchically in the form of a work plan, consecutively assimilating numerous procedures that act as filters to get rid of undesirable compounds (Cruz-Monteagudo et al., 2017). VS methods can be classified into two major groups: (a) ligand-based methods and (b) receptor-based methods (Table 14.3).
The availability of high-resolution structures of many SARS-CoV-2 proteins (Table 14.4) enabled the identification of lead drug candidates for SARS-CoV-2 in a timely manner using in silico screening methods. Previous studies have shown that the number of compounds screened in a structure-based in silico screen affects the quality of the resulting hits and that the potency of the hits derived increases as the number of compounds screened increases (Lyu et al., 2019).

High-throughput screening
Designing widely diversified biological libraries and analyzing them via HTS is a much more realistic way to progress a strain improvement program as well as to manufacturing size.  reported that cinanserin, a well-characterized serotonin antagonist, has a cationÀπ interactions with H41 and E166 of Mpro and the potential to become an antiviral drug lead . The same study also indicated (a) Ebselen, (b) Disulfiram, (c) Tideglusib, (d) Carmofur, (e) Shikonin, (f) PX-12 as a potent viral target for M pro (Fig. 14.2).

Webservers
There are few webservers that were developed by researchers and freely accessible to understand or predict targets or binding sites. For example, "D3Targets-2019-nCoV" (https://www.d3pharma.com/D3Targets-2019-nCoV/index.php) . This server has "20 viral proteins and 22 human proteins recorded in virus infection, replication and release, with 69 different conformations and 557 potential ligand-binding pockets (Yang & Zhang, 2015)." The authors have not included nonpeer-reviewed publications webservers or yet published servers in this chapter.

Conclusion
In this paper, we gave an overview of the characteristic features, symptoms, replication cycle of SARS-CoV-2. This novel virus spread majorly through respiratory droplets and close contact. It is a human-borne disease and is spread from human to human. The main objective is to discuss the different types of drugs approved to use against SARS-CoV-2 viral diseases, selected from the DrugBank database. While peer-studied journals, assessments, s and trials, online tools are fastening up the sharing of COVID-19 information, allowing quick and free access for both public and researchers. Different databases are   incorporated in this paper with their individual links to easily fetch detailed information and statistical data of SARS-CoV-2, COVID-19 disease. This paper also provides popular software used for the VS of potential drugs and their specific targets. HTS plays an important role in the discovery of antiviral drugs from high-content compound libraries. These databases maintain some of the applications to record the SARS-CoV-2 approach, site, gene, and mutagenesis of this novel virus are really advantageous. By understanding the complexity and mechanism of all viral proteins, virtual trials, molecular docking, therapeutic intervention, and developing vaccination may provide a lead for COVID-19 treatment to curtail the death rate. VS and molecular docking are effective ways of discovering a potential drug that inhibits the protein responsible for the pathogenesis of the viral particle. Therefore, this chapter provides a piece of complete information about the SARS-CoV-2 virus, potential drugs, and VS methods. And also provides a different database to reach out for information related to the COVID-19 pandemic and its future.

Future prospective
The scenario of the outbreak is taking on entirely different characteristics. We will know whether the vaccines are efficiently working to control SARS-CoV-2 spread which remains a far goal to accomplish or is already there. The unprecedented mass and simultaneous vaccination of the population will undoubtedly reveal heterogeneity in vaccination responses and some individuals may not produce robust antibody responses or be protected. And in the future, the hottest issue will be vaccines availability and its unbiased distribution in and around the world. Thus, the vaccine may become a fortunate measure of power. And in the long run, maybe more than one vaccine will be needed to ensure reasonable universal access, shield, and immunity against viral alternates. Hence, vaccination is the only important approach to end this outbreak which provides an effective measure of hope in the future.
Countries should work in isolation from each other to prolong the pandemic. Unless the countries work together to gage up prevention efforts, the risk of rising in the cases including other disasters will remain a constant threat.