Competency of Certain Natural Products as Inhibitors for SARS-CoV-2: the In-silico Exploration

Abundance of natural products in edible plants and their vast role in the treatment of almost all the diseases is the motivation behind the investigation of their candidature as inhibitor for COVID-19. Seven selected natural products named, (1) bicuculline, (2) boldine, (3) 1-(4-chlorophenyl)-3-(5-methylfuran-2-yl) prop-2-en-1-one, (4) piplartine, (5) formononetin, (6) isoformononetin, and (7) tectorigenin, were first examined for drug likeness and reactivity. The activity at various atomic sites has been inspected graphically through molecular electrostatic potential surface (MESP) plot and quantitative description of the same was given within the framework of conceptual DFT. The analyses of Fukui and Parr functions have exposed the similar active sites as depicted by MESP surface analysis. Furthermore, the molecular docking studies of the abovementioned compounds (inhibitor) with the main protease present in SARS-CoV-2 (6LU7) have been performed. The comparison of docking parameters such as binding affinity, inhibition constant with strength and bond-lengths of hydrogen bond had revealed that isoformononetin is the most apposite prospect for the same.