Identification of Potent Inhibitors of COVID-19 Main Protease Enzyme by Molecular Docking Study

Within the span of a few months, the severe acute respiratory syndrome coronavirus, COVID-19 (SARS-CoV-2), has proven to be a pandemic, affecting the world at an exponential rate. It is extremely pathogenic and causes communicable infection in humans. Viral infection causes difficulties in breathing, sore throat, cough, high fever, muscle pain, diarrhea, dyspnea, and may lead to death. Finding a proper drug and vaccines against this virus is the need of the hour. The RNA genome of COVID19 codes for the main protease M^pro, which is required for viral multiplication. To identify possible antiviral drug(s), we performed molecular docking studies. Our screen identified ten biomolecules naturally present in Aspergillus flavus and Aspergillus oryzae fungi. These molecules include Aspirochlorine, Aflatoxin B1, Alpha-Cyclopiazonic acid, Sporogen, Asperfuran, Aspergillomarasmine A, Maltoryzine, Kojic acid, Aflatrem and Ethyl 3-nitropropionic acid, arranged in the descending order of their docking score. Aspirochlorine exhibited the docking score of – 7.18 Kcal/mole, higher than presently used drug Chloroquine (-6.2930522 Kcal/mol) and out of ten ligands studied four has docking score higher than chloroquine. These natural bioactive compounds could be tested for their ability to inhibit viral growth in- vitro and in-vivo.