Lead Finding from Selected Flavonoids with Antiviral (SARS-CoV-2) Potentials against COVID-19: An in-silico Evaluation.

Gorla, Uma Sankar; Rao, Gsn Koteswara; Kulandaivelu, Uma Sankar; Alavala, Rajasekhar Reddy; Panda, Siva Prasad

BACKGROUND COVID-19, a pandemic respiratory contagious viral (SARS-CoV-2) disease associated with high morbidity and mortality worldwide. Currently, there areno effective preventive or treatment strategies for COVID-19 and has been declared as a global health emergency by WHO. In silico molecular docking studies can be useful to predict the binding affinity between the phytocompound and the target protein and play a vital role in finding an inhibitor through structure-based drug design. OBJECTIVE In this aspect, our objective was to screen essential flavonoids against possible protein targets such as SARS-CoV-2 spike glycoprotein receptor binding domain (RBD-S) and host Angiotensin Converting Enzyme-2 protease domain (PD-ACE-2) using in silico molecular docking studies. METHODS Approximately 49 flavonoids were identified, evaluated for their drug likeness based on Lipinski rule, bioactivity scores, antiviral and toxicity profiles using SwissADME, Molinspiration, PASS and GUSAR online tools. The flavonoids that passed Lipinski rule were subjected to in silico analysis through molecular docking on RBD-S and PD-ACE-2 using Molegro Virtual Docker v6.0. RESULTS The bioactive flavonoids that showed NIL violations and found in compliance with Lipinski rule were selected for docking studies. In silicoanalysis reported that biochanin A and silymarin bind significantly at the active sites of RBD-Sand PD-ACE-2 with a MolDock score of -78.41and -121.28 kcal/mol respectively. Bioactivity scores, antiviral potential and tox-icity profiles were predicted for the top interacting phytocompounds and substantial relevant data was reported. CONCLUSION The current outcomes created a new paradigm in understanding biochanin A and silymarin bioflavonoids as potent inhibitors of RBD-Sand PD-ACE-2 targets respectively, further work can be extended to confirm their therapeutic potential in COVID-19.