Dietary flavonoids as competitive inhibitors of covid 19 major protease

Covid 19 is a positive strand RNA virus which causes mild to severe respiratory symptom in human beings. This disease has reached a pandemic state and still exhibit linear increase in countries like USA, India, and Brazil. In the absence of any vaccine and specific therapeutics, it is necessary to look for new therapeutic agents. In this direction, studies were made with plant bioactive compounds present in fruits and other food materials for their anti-viral properties. The target was selected as major protease of the virus since this protease plays an important role in the development of the virus. The binding efficiency of 20 flavonoids to covid19 major protease was done using Auto Dock vina. Out of 20 flavonoids tested, 17 could bind to the amino acid His41 in the active site. However only apigenin and genistein could pass through Lipinski rule of five and ADMET analysis. While apigenin bind to His 41in pose 1, genistein could bind to His 41 in pose 6 and Cys145 in pose 8 in the active site pocket of corona protease. While the binding affinity for apigenin is -6.8, it is -6.7 for genistein. These two flavonoids could act as competitive inhibitors for SARS-CoV-2 cysteine protease.