4.  Conclusion
SARS-CoV-2 which causes the deadly and highly infectious COVID-19 remains an unmet medical issue that requires urgent attention, owing to the number of deaths it is causing globally. We report here a computational approach for a repurposing screening program against two crucial SARS-CoV-2 drug targets viz. the spike protein and the main protease. We discovered that the drug rutin, showed a high binding potency against both the drug targets and may therefore be capable of eliciting reduction in viral load. The current study delineates that the highly effective repurposed drug rutin has the potential to obtain strong inhibition against SARS-CoV-2 spike protein and main protease. Rutin showed high binding efficiency against spike protein and main protease having an XP Glide score of –8.367 kcal/mol and –11.553 kcal/mol.
Further, the molecular interactions of rutin with both the drug targets were analysed thoroughly with the help of molecular dynamics simulation studies. The simulations for spike protein and main protease provided us with the stable trajectory analysis for both the targets. We analyzed various parameters which include RMSD, RMSF, radius of gyration, SASA, binding energies, hydrogen bond interactions, secondary structure contents, and cluster formation throughout the simulation, which proposed insights about the stable binding and compactness due to strong interaction of the rutin with both the drug targets. Through this in silico approach, the repurposed drug, rutin depicted reliable inhibition of two vital proteins and therefore may lead to elicitation of anti-SARS-CoV-2 activity.