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Due to alarming outbreak of pandemic COVID‐19 in recent times, there is a strong need to discover and identify new antiviral agents acting against SARS CoV‐2. Among natural products, lignan derivatives have been found effective against several viral strains including SARS CoV‐2. Total of twenty‐seven reported antiviral lignan derivatives of plant origin have been selected for computational studies to identify the potent inhibitors of SARS CoV‐2. Molecular docking study has been carried out in order to predict and describe molecular interaction between active site of enzyme and lignan derivatives. Out of identified hits, clemastatin B and erythro‐strebluslignanol G demonstrated stronger binding and high affinity with all selected proteins. Molecular dynamics simulation studies of clemastin B and savinin against promising targets of SARS CoV‐2 have revealed their inhibitory potential against SARS CoV‐2. In fine, in‐silico computational studies have provided initial breakthrough in design and discovery of potential SARS CoV‐2 inhibitors.

Background: Aspartic protease found in plasmodium parasites such as plasmepsin I, II and IV plays an important role in the degradation of hemoglobin. The studies have shown that effective drug must be able to inhibit more than one type of plasmepsin to avoid further growth of parasites and to prevent resistance of drug. Therefore, plasmepsins are believed to be excellent drug target for malarial disease. Extract of the plant Euphorbia hirta has been proved to exert antimalarial activity. However, molecular mechanism of this activity was not described. Aim: The aim of present investigation is to identify antimalarial phytochemicals of Euphorbia hirta as plasmepsin protease inhibitors using an in silico approach. Materials and methods: Docking studies were performed on three different protein targets plasmepsin I, II, and IV using iGEMDOCK. ADME and bioactivity predictions were done using molinspiration online tool. Toxicity studies were performed using ProTox-II online tool. Results: In the docking studies seven compounds showed significant inhibitory activity with low docking score as compared to standard drug artemisinin. Six compounds showed no violations as per Lipinski rule. Bioactivity prediction states that all the compounds may act through enzyme inhibition. The results of in silico studies suggest that out of the eleven selected phytochemicals isorhamnetin and pinocembrin have more drug likeliness properties and lesser in silico toxicity with more binding affinity than artemisinin on all receptors.  Conclusion: These findings indicate that isorhamnetin and pinocembrin have promising potential for development of antimalarial drug as plasmepsin inhibitors.

The DNA repair process protects the cells from DNA damaging agent by multiple pathways. Majority of the cancer therapy cause DNA damage which leads to apoptosis. The cell has natural ability to repair this damage which ultimately leads to development of resistance of drugs. The key enzymes involved in DNA repair process are poly(ADP-ribose) (PAR) and poly(ADP-ribose) polymerases (PARP). Tumor cells repair their defective gene via defective homologues recombination (HR) in the presence of enzyme PARP. PARP inhibitors inhibit the enzyme poly(ADP-ribose) polymerases (PARPs) which lead to apoptosis of cancer cells. Current clinical data shows the role of PARP inhibitors is not restricted to BRCA mutations but also effective in HR dysfunctions related tumors. Therefore, investigation in this area could be very helpful for future therapy of cancer. This review gives detail information on the role of PARP in DNA damage repair, the role of PARP inhibitors and chemistry of currently available PARP inhibitors.

Background: Novel Corona virus is a type of enveloped viruses with a single stranded RNA enclosing helical nucleocapsid. The envelope consists of spikes on the surface which are made up of proteins through which virus enters into human cells. Until now there is no specific drug or vaccine available to treat COVID-19 infection. In this scenario, reposting of drug or active molecules may provide rapid solution to fight against this deadly disease. Objective: We had selected 30 phytoconstituents from the different plants which are reported for antiviral activities against corona virus (CoVs) and performed insilico screening to find out phytoconstituents which have potency to inhibit specific target of novel corona virus. Methods: We had perform molecular docking studies on three different proteins of novel corona virus namely COVID-19 main protease (3CL pro), papain-like protease (PL pro) and spike protein (S) attached to ACE2 binding domain. The screening of the phytoconstituents on the basis of binding affinity compared to standard drugs. The validations of screened compounds were done using ADMET and bioactivity prediction. Results: We had screened five compounds biscoclaurine, norreticuline, amentoflavone, licoricidin and myricetin using insilico approach. All compounds found safe in insilico toxicity studies. Bioactivity prediction reviles that these all compounds may act through protease or enzyme inhibition. Results of compound biscoclaurine norreticuline were more interesting as this biscoclaurine had higher binding affinity for the target 3CLpro and PLpro targets and norreticuline had higher binding affinity for the target PLpro and Spike protein. Conclusion: Our study concludes that these compounds could be further explored rapidly as it may have potential to fight against COVID-19.

Background: Epidermal growth factor receptor (EGFR, ErBb) belongs to family of receptor tyrosine kinase (RTKs) played important role in multiple cell signaling pathways, which includes cell growth, multiplication and apoptosis etc. Overexpression of EGFR results in to development of malignant cells. Therefore EGFR considered as one of the important target for cancer therapy. Objective: In this study we performed virtual screening of 329 flavonoids obtained from Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target (NPACT) database to identify novel EGFR inhibitors. Materials and methods: Virtual screening carried out using different insilico methods which includes molecular docking studies, prediction of druglikeness, insilico toxicity studies and bioactivity prediction. Results: Six flavonoids NPACT00061, NPACT00062, NPACT00066, NPACT00280, NPACT00700 and NPACT00856 were identified as potential EGFR inhibitors with good docking score and druglikeness properties. In the insilico toxicity studies, compound NPACT00061, NPACT00062, NPACT00066 and NPACT00856 were found to be carcinogenic. Finally, two flavonoids NPACT00280 and NPACT00700 were recognized as novel EGFR inhibitors. Conclusion: Our findings suggest that compound NPACT00280 and NPACT00700 could be further explored as novel EGFR inhibitors.

Currently, the entire globe is under the deadliest pandemic of Covid-19 caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). At present, no specific treatment is available to combat COVID-19 infection. Euphorbia hirta (Euphorbiaceae) have been reported for a variety of biological activities, including antiviral. The present investigation aimed to identify potential phytoconstituents of the plant E. hirta from the category flavonoids and coumarins against the SARS-CoV-2 using in silico approach. The molecular docking studies were performed using two different targets of SARS-CoV-2, namely Main protease (Mpro; PDB ID: 6M2N) and RNA-dependent RNA polymerase (RdRp; PDB ID: 7BW4). Based on the molecular docking study in comparison with standard drug, four compounds, namely Euphrobianin, Quercetin, 3-o-alpha-rhamnoside, Isoquercitrin, and rutin, were screened against the target Mpro. Three phytoconstituents, euphorbianin, myricetin, and rutin, were screened against the target RdRp. In the in silico toxicity studies of screened phytoconstituents, except myrectin all were predicted safe. Results of euphorbianin and rutin were found more interesting as both compounds had high binding affinity against both targets. Finally, we want to conclude that euphrobianin, quercetin 3-o-alpha-rhamnoside, isoquercitrin, and rutin could be further explored rapidly as they may have the potential to fight against COVID-19.

Introduction Theaflavins belong to the class of polyphenols that are predominantly found in black tea. The major derivatives of theaflavins found in black tea are theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3′-gallate (TF2B), and theaflavin-3,3′-digallate (TF3). Theaflavin-3,3′-digallate (TF3) is a natural compound present in black tea and known to possess antiviral activity. This study had attempted to explore the potential role of TF3 in inhibiting various stages of the SARS-CoV-2 life cycle. Methods Molecular docking studies of TF3 along with positive controls was performed on eight different targets of SARS-CoV-2 followed by binding free energy (MM-GBSA) calculations. The docked complexes with favourable docking and binding free energy results were subjected to molecular dynamics (MD) simulation studies to assess the stability of the dock complex. Finally, TF3 and all the positive controls were taken for ADMET analysis. Results The docking and binding free energy results of TF3 was compared against the positive controls. TF3 showed the highest binding energy against all the targets and formed more stable interactions for a longer duration on MD simulations with CLpro, RdRp, helicase and spike protein. Also, the promising in-silico ADMET profile further warrants the exploration of this compound through in-vitro and in-vivo methods. Conclusion Through this study, we tried to evaluate the role of theaflavin-3,3’-digallate on multiple targets of SARS-CoV-2, and the positive in-silico results which were obtained on various pharmacodynamic and pharmacokinetic parameters, give a ray of hope as a potential therapeutic drug to this rapidly spreading disease. The search for a curative therapy for SARS-CoV-2 is still ongoing. The favourable preliminary results of TF3 through in-silico analysis offers a ray of hope in ending this devasting pandemic. Supplementary Information The online version contains supplementary material available at 10.1007/s42250-022-00376-7.