Potential of phytocompounds from Brassica oleracea targeting S2-domain of SARS-CoV-2 spike glycoproteins: Structural and molecular insights

By 24th Sep. 2021, there are more than 229 million COVID-19 cases worldwide, the researchers are tirelessly working to discover and develop an efficient drug molecule against this devastative viral infection. This study aims to evaluate the inhibitory efficiency of the organic acids and phenolic compounds present in Brassica oleracea (Tronchuda Cabbage) against spike glycoprotein in SARS-CoV-2. Thirty-seven phytocompounds are screened on the basis of their molecular weight (<500 g/mol) and 14 ligands are docked using Autodock Vina and Autodock4 (version 4.2.6). The stability of the top five docked complexes was analyzed using classical molecular dynamics (MD) simulation. ADMET analysis is performed for the top five compounds and their targets are identified using SwissTargetPrediction. Phytoactives from B. oleracea namely Astragalin, 3-p-coumaroylquinic acid, 4-p-coumaroylquinic acid and sinapoyl-D-glucoside showed high binding affinities and free energy of binding during molecular docking and MD simulation studies (∼ 8.5-9.0 kcal/mol) for the spike glycoprotein trimer of SARS-CoV2. The ADMET analysis revealed that these phytocompounds have good solubility in the aqueous phase and that they don't penetrate the blood brain barrier. Moreover, there is no P-gp substrate inhibition, CYP1A2 inhibition, CYP2C19 inhibition, CYP2C9 inhibition, CYP2D6 inhibition and CYP3A4 inhibition observed for these compounds. Additionally, zero PAINS alerts were reported. These findings from molecular docking and MD simulation studies suggest that astragalin and coumaroylquinic acids from Tronchuda cabbage possess potential inhibitory capacity against spike glycoprotein trimer of SARS-CoV-2 and could be further taken up as lead targets for drug discovery.