In Silico Studies of Some Isoflavonoids as Potential Candidates against COVID-19 Targeting Human ACE2 (hACE2) and Viral Main Protease (M^pro)

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the "COVID-19" disease that has been declared by WHO as a global emergency. The pandemic, which emerged in China and widespread all over the world, has no specific treatment till now. The reported antiviral activities of isoflavonoids encouraged us to find out its in silico anti-SARS-CoV-2 activity. In this work, molecular docking studies were carried out to investigate the interaction of fifty-nine isoflavonoids against hACE2 and viral M^pro. Several other in silico studies including physicochemical properties, ADMET and toxicity have been preceded. The results revealed that the examined isoflavonoids bound perfectly the hACE-2 with free binding energies ranging from -24.02 to -39.33 kcal mol^-1, compared to the co-crystallized ligand (-21.39 kcal mol^-1). Furthermore, such compounds bound the M^pro with unique binding modes showing free binding energies ranging from -32.19 to -50.79 kcal mol^-1, comparing to the co-crystallized ligand (binding energy = -62.84 kcal mol^-1). Compounds 33 and 56 showed the most acceptable affinities against hACE2. Compounds 30 and 53 showed the best docking results against M^pro. In silico ADMET studies suggest that most compounds possess drug-likeness properties.