Identification of Potential Scaffolds From the Shrub Justicia Adhatoda Against SARS-CoV-2 Main Protease Target

Author(s):  
Debanjan Sen ◽  
Samhita Bhaumik ◽  
Gourav Roy ◽  
Ravikumar Muttineni ◽  
Rasbihari Hembram ◽  
...  

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious and pathogenic virus. To date, there is a lack of proper medication against this virus, which has triggered the scientific community to find therapeutics. Searching of SARS-CoV-2 main protease inhibitors from anti-viral natural products based on traditional knowledge may be an effective approach. In this work, structure-based virtual screening of the compounds of Justicia adhatoda was performed against SARS-CoV-2 Mpro, followed by ADME filtration, molecular dynamics, and MMGBSA-based binding free energy calculation. On the basis of docking score, crucial interacting amino acid residues, molecular dynamics, and binding energy profile, three novel phenolic compounds JA_38b, JA_38c, and JA_39 were selected as potential binders against SARS-CoV-2 Mpro. This information may be used to develop potential therapeutics countermeasures against SARS-CoV-2 infection after in vitro and detailed pharmacological study.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shin-ichiro Hattori ◽  
Nobuyo Higashi-Kuwata ◽  
Hironori Hayashi ◽  
Srinivasa Rao Allu ◽  
Jakka Raghavaiah ◽  
...  

AbstractExcept remdesivir, no specific antivirals for SARS-CoV-2 infection are currently available. Here, we characterize two small-molecule-compounds, named GRL-1720 and 5h, containing an indoline and indole moiety, respectively, which target the SARS-CoV-2 main protease (Mpro). We use VeroE6 cell-based assays with RNA-qPCR, cytopathic assays, and immunocytochemistry and show both compounds to block the infectivity of SARS-CoV-2 with EC50 values of 15 ± 4 and 4.2 ± 0.7 μM for GRL-1720 and 5h, respectively. Remdesivir permitted viral breakthrough at high concentrations; however, compound 5h completely blocks SARS-CoV-2 infection in vitro without viral breakthrough or detectable cytotoxicity. Combination of 5h and remdesivir exhibits synergism against SARS-CoV-2. Additional X-ray structural analysis show that 5h forms a covalent bond with Mpro and makes polar interactions with multiple active site amino acid residues. The present data suggest that 5h might serve as a lead Mpro inhibitor for the development of therapeutics for SARS-CoV-2 infection.


2021 ◽  
Vol 14 (6) ◽  
pp. 541
Author(s):  
Hani A. Alhadrami ◽  
Ahmed M. Sayed ◽  
Heba Al-Khatabi ◽  
Nabil A. Alhakamy ◽  
Mostafa E. Rateb

The COVID-19 pandemic is still active around the globe despite the newly introduced vaccines. Hence, finding effective medications or repurposing available ones could offer great help during this serious situation. During our anti-COVID-19 investigation of microbial natural products (MNPs), we came across α-rubromycin, an antibiotic derived from Streptomyces collinus ATCC19743, which was able to suppress the catalytic activity (IC50 = 5.4 µM and Ki = 3.22 µM) of one of the viral key enzymes (i.e., MPro). However, it showed high cytotoxicity toward normal human fibroblasts (CC50 = 16.7 µM). To reduce the cytotoxicity of this microbial metabolite, we utilized a number of in silico tools (ensemble docking, molecular dynamics simulation, binding free energy calculation) to propose a novel scaffold having the main pharmacophoric features to inhibit MPro with better drug-like properties and reduced/minimal toxicity. Nevertheless, reaching this novel scaffold synthetically is a time-consuming process, particularly at this critical time. Instead, this scaffold was used as a template to explore similar molecules among the FDA-approved medications that share its main pharmacophoric features with the aid of pharmacophore-based virtual screening software. As a result, cromoglicic acid (aka cromolyn) was found to be the best hit, which, upon in vitro MPro testing, was 4.5 times more potent (IC50 = 1.1 µM and Ki = 0.68 µM) than α-rubromycin, with minimal cytotoxicity toward normal human fibroblasts (CC50 > 100 µM). This report highlights the potential of MNPs in providing unprecedented scaffolds with a wide range of therapeutic efficacy. It also revealed the importance of cheminformatics tools in speeding up the drug discovery process, which is extremely important in such a critical situation.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3193 ◽  
Author(s):  
Olujide O. Olubiyi ◽  
Maryam Olagunju ◽  
Monika Keutmann ◽  
Jennifer Loschwitz ◽  
Birgit Strodel

We use state-of-the-art computer-aided drug design (CADD) techniques to identify prospective inhibitors of the main protease enzyme, 3CLpro of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19. From our screening of over one million compounds including approved drugs, investigational drugs, natural products, and organic compounds, and a rescreening protocol incorporating enzyme dynamics via ensemble docking, we have been able to identify a range of prospective 3CLpro inhibitors. Importantly, some of the identified compounds had previously been reported to exhibit inhibitory activities against the 3CLpro enzyme of the closely related SARS-CoV virus. The top-ranking compounds are characterized by the presence of multiple bi- and monocyclic rings, many of them being heterocycles and aromatic, which are flexibly linked allowing the ligands to adapt to the geometry of the 3CLpro substrate site and involve a high amount of functional groups enabling hydrogen bond formation with surrounding amino acid residues, including the catalytic dyad residues H41 and C145. Among the top binding compounds we identified several tyrosine kinase inhibitors, which include a bioflavonoid, the group of natural products that binds best to 3CLpro. Another class of compounds that decently binds to the SARS-CoV-2 main protease are steroid hormones, which thus may be endogenous inhibitors and might provide an explanation for the age-dependent severity of COVID-19. Many of the compounds identified by our work show a considerably stronger binding than found for reference compounds with in vitro demonstrated 3CLpro inhibition and anticoronavirus activity. The compounds determined in this work thus represent a good starting point for the design of inhibitors of SARS-CoV-2 replication.


2020 ◽  
Vol 7 ◽  
Author(s):  
Rounak Chourasia ◽  
Srichandan Padhi ◽  
Loreni Chiring Phukon ◽  
Md Minhajul Abedin ◽  
Sudhir P. Singh ◽  
...  

The COVID-19 pandemic caused by novel SARS-CoV-2 has resulted in an unprecedented loss of lives and economy around the world. In this study, search for potential inhibitors against two of the best characterized SARS-CoV-2 drug targets: S1 glycoprotein receptor-binding domain (RBD) and main protease (3CLPro), was carried out using the soy cheese peptides. A total of 1,420 peptides identified from the cheese peptidome produced using Lactobacillus delbrueckii WS4 were screened for antiviral activity by employing the web tools, AVPpred, and meta-iAVP. Molecular docking studies of the selected peptides revealed one potential peptide “KFVPKQPNMIL” that demonstrated strong affinity toward significant amino acid residues responsible for the host cell entry (RBD) and multiplication (3CLpro) of SARS-CoV-2. The peptide was also assessed for its ability to interact with the critical residues of S1 RBD and 3CLpro of other β-coronaviruses. High binding affinity was observed toward critical amino acids of both the targeted proteins in SARS-CoV, MERS-CoV, and HCoV-HKU1. The binding energy of KFVPKQPNMIL against RBD and 3CLpro of the four viruses ranged from −8.45 to −26.8 kcal/mol and −15.22 to −22.85 kcal/mol, respectively. The findings conclude that cheese, produced by using Lb. delbrueckii WS4, could be explored as a prophylactic food for SARS-CoV-2 and related viruses. In addition, the multi-target inhibitor peptide, which effectively inhibited both the viral proteins, could further be used as a terminus a quo for the in vitro and in vivo function against SARS-CoV-2.


2012 ◽  
Vol 11 (04) ◽  
pp. 907-924 ◽  
Author(s):  
DAWEI HUANG ◽  
XIAOHUI LI ◽  
ZHILONG XIU

Inhibitors of histone deacetylases (HDACs) have become an attractive class of anticancer agent. To understand the interaction between HDAC8 and inhibitors, including "pan-" inhibitors that inhibit many HDACs isoforms and selective inhibitors with no linker domain, docking and molecular dynamics simulation were conducted. Docking results showed the presence of π-π interactions between "linkerless" inhibitors and the aromatic amino acid residues of HDAC8 in the active site. Binding between HDAC8 and inhibitors was also stabilized by hydrogen bond and hydrophobic interaction. In molecular dynamics simulations, the zinc ion was shown to coordinate one more atom of HDAC8-"linkerless" inhibitor complexes than HDAC8-"pan-" inhibitor complexes. Persistent hydrogen bonds also existed between Tyr306 of HDAC8 and some inhibitors. When inhibitors with large cap groups bound to the active pocket of HDAC8, Phe152 and Met274 shifted from their initial positions and the entrance of the active pocket became more open, resulting in the formation of sub-pocket. Hydrophobic interactions contributed most favorably to the binding free energy between HDAC8 and inhibitors. Lys33, Asp178, Asp267, Tyr306 and Leu308 of HDAC8 were favorable for binding with all inhibitors.


2021 ◽  
Vol 22 (21) ◽  
pp. 11739
Author(s):  
Rai C. Silva ◽  
Humberto F. Freitas ◽  
Joaquín M. Campos ◽  
Njogu M. Kimani ◽  
Carlos H. T. P. Silva ◽  
...  

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received global attention due to the serious threat it poses to public health. Since the outbreak in December 2019, millions of people have been affected and its rapid global spread has led to an upsurge in the search for treatment. To discover hit compounds that can be used alone or in combination with repositioned drugs, we first analyzed the pharmacokinetic and toxicological properties of natural products from Brazil’s semiarid region. After, we analyzed the site prediction and druggability of the SARS-CoV-2 main protease (Mpro), followed by docking and molecular dynamics simulation. The best SARS-CoV-2 Mpro complexes revealed that other sites were accessed, confirming that our approach could be employed as a suitable starting protocol for ligand prioritization, reinforcing the importance of catalytic cysteine-histidine residues and providing new structural data that could increase the antiviral development mainly against SARS-CoV-2. Here, we selected 10 molecules that could be in vitro assayed in response to COVID-19. Two compounds (b01 and b02) suggest a better potential for interaction with SARS-CoV-2 Mpro and could be further studied.


2020 ◽  
Author(s):  
Raphael J. Eberle ◽  
Danilo S. Olivier ◽  
Marcos S. Amaral ◽  
Dieter Willbold ◽  
Raghuvir K. Arni ◽  
...  

AbstractSince the first report of a new pneumonia disease in December 2019 (Wuhan, China) up to now WHO reported more than 50 million confirmed cases and more than one million losses, globally. The causative agent of COVID-19 (SARS-CoV-2) has spread worldwide resulting in a pandemic of unprecedented magnitude. To date, no clinically safe drug or vaccine is available and the development of molecules to combat SARS-CoV-2 infections is imminent. A well-known strategy to identify molecules with inhibitory potential against SARS-CoV-2 proteins is the repurposing of clinically developed drugs, e.g., anti-parasitic drugs. The results described in this study demonstrate the inhibitory potential of quinacrine and suramin against SARS-CoV-2 main protease (3CLpro). Quinacrine and suramin molecules present a competitive and non-competitive mode of inhibition, respectively, with IC50 and KD values in low μM range. Using docking and molecular dynamics simulations we identified a possible binding mode and the amino acids involved in these interactions. Our results suggested that suramin in combination with quinacrine showed promising synergistic efficacy to inhibit SARS-CoV-2 3CLpro. The identification of effective, synergistic drug combinations could lead to the design of better treatments for the COVID-19 disease. Drug repositioning offers hope to the SARS-CoV-2 control.


2019 ◽  
Vol 19 (2) ◽  
pp. 461
Author(s):  
Herlina Rasyid ◽  
Bambang Purwono ◽  
Thomas S Hofer ◽  
Harno Dwi Pranowo

Lung cancer was a second common cancer case due to the high cigarette smoking activity both in men and women. One of protein receptor which plays an important role in the growth of the tumor is Epidermal Growth Factor Receptor (EGFR). EGFR protein is the most frequent protein mutation in cancer and promising target to inhibit the cancer growth. In this work, the stability of the hydrogen bond as the main interaction in the inhibition mechanism of cancer will be evaluated using molecular dynamics simulation. There were two compounds (A1 and A2) as new potential inhibitors that were complexed against the EGFR protein. The dynamic properties of each complexed were compared with respect to erlotinib against EGFR. The result revealed that both compounds had an interaction in the main catalytic area of protein receptor which is at methionine residue. Inhibitor A1 showed additional interactions during simulation time but the interactions tend to be weak. Inhibitor A2 displayed a more stable interaction. Following dynamics simulation, binding free energy calculation was performed by two scoring techniques MM/GB(PB)SA method and gave a good correlation with the stability of the complex. Furthermore, potential inhibitor A2 had a lower binding free energy as a direct consequence of the stability of hydrogen bond interaction.


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