Computational Approach Revealed Potential Affinity of Antiasthmatics Against Receptor Binding Domain of 2019n-Cov Spike Glycoprotein

The novel COVID-19 pandemic is now a health threat, with a deep-felt impact worldwide. The new coronavirus 2019 (2019 n-Cov) binds to host human receptors through Receptor Binding Domain RBD of Spike glycoprotein (S), making it a prominent drug target. The present study aims to identify new potential hits that can inhibit the S protein using in silico approaches. Several natural and synthetics compounds (antiasthmatics, Antiviral, Antimalarial, Antibacterial, Anti-Inflammatory, cyclic peptide, and cyclic bis) were screened by molecular docking using AutoDock Vina. Additionally, we tested calcitriol and three known drugs (Azithromycin, HydroxyChloroquine, and Chloroquine ) against the spike protein to found if they have any direct interaction.
Our finding consists of 4 potential synthetic compounds from PubChem database, known for their antiasthmatic effects, that show highly binding energies each (-8.6 kcal/mol, 7.7kcal/mol, -7.2 kcal/mol and -7.0 kcal/mol). Another 5 natural compounds from the South African natural sources database (SANCDB) that bind to RBD of Spike with significant energy each: (Marchantin C with -7.3 kcal/mol, Riccardin C with -7.0 kcal/mol, Digitoxigenin-glucoside with -6.9 kcal/mol, D-Friedoolean-14-en-oic acid with -6.8 kcal/mol and, Spongotine A with -6.7 kcal/mol). The FaF-Drugs server was used to evaluate the drug-like properties of the identified compounds. Additionally, Calcitriol, Azithromycin, and HydroxyChloroquine have an appreciable binding affinity to 2019-nCoV S, suggesting a possible mechanism of action. Using in silico approaches like molecular docking and pharmacokinetic properties, we showed new potential inhibitors. Our findings need further analysis, and chemical design for more effective derivatives of these compounds speculated to disrupt the viral recognition of host receptors.