Identification of Possible Inhibitors of SARS-CoV-2 Main Protease From Some Bioactive Compounds of Artemisia Annua: An in Silico Approach

Abstract

\n The inhibitory potential of Artemisia annua, a well-known antimalarial herb, against several viruses including the coronavirus is increasingly gaining recognition. The plant extract has shown significant activity against both the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the novel SARS-CoV-2, that is currently ravaging the world. It is therefore necessary to identify the bioactive compounds of the plants that are responsible for this activity, for the purpose of designing drugs against SARS-CoV-2. In this study, we employed in silico techniques comprising of molecular docking, binding free energy calculations, pharmacophore modelling as well as druglikeness, pharmacokinetics and toxicity predictions, to identify potential inhibitors of the SARS-CoV-2 main protease (Mpro) from 168 bioactive compounds of Artemisia annua. Rhamnocitrin, Isokaempferide, Kaempferol, Quercimeritrin, Apigenin, Penduletin, Isoquercitrin, Astragalin, Luteolin-7-glucoside and Isorhamnetin were ranked highest; with docking scores ranging from -7.84 to -7.15 kcal/mol compared with -6.59 kcal/mol demonstrated by the standard ligand. Rhamnocitrin, Isokaempferide and Kaempferol, like the standard ligand interacted with important active site amino acid residues like HIS 41, CYS 145, ASN 142, and GLU 166, among others. These compounds also possess acceptable druglike properties and safety profile. Hence, they could be considered for experimental studies and further development into drugs against SARS-CoV-2.