Identification of some novel oxazine substituted 9-anilinoacridines as SARS-CoV-2 inhibitors for COVID-19 by molecular docking, free energy calculation and molecular dynamics studies

Coronavirus disease (COVID-19), a life-threatening disease, is caused by SARS-CoV-2. The targeted therapeutics of small molecules helps the scientific community to fight against SARS-CoV-2. In this article, some oxazine substituted 9-anilinoacridines (A1-A48) was designed by docking, MM-GBSA and molecular dynamics (MD) simulation studies for their COVID-19 inhibitory activity. The docking of ligandsA1-A48against SARS-CoV-2 (PDB ID: 5R82) are performed by using Glide module,in silicoADMET screening by QikProp module, binding energy using Prime MM-GB/SA module, MD simulation by Desmond module and atomic charges were derived by Jaguar module of Schrodinger suit 2019-4. CompoundA38has the highest G-score (-7.83) when compared to all the standard compounds which are proposed for COVID-19 treatment such as ritonavir (-7.48), lopinavir (-6.94), nelfinavir (-5.93), hydroxychloroquine (-5.47) and mataquine (-5.37). CompoundsA13,A23,A18,A7,A48,A46,A32,A20,A1andA47are significantly active against SARS-CoV-2 main protease when compared with hydroxychloroquine and mataquine. The residues GLN19, THR24, THR25, THR26, LEU27, HIE41, SER46, MET49, ASN119, ASN142, HIE164, MET165, ASP187, ARG188 and GLN189 of SARS-CoV-2 main protease play a crucial role in binding with ligands. Thein silicoADMET properties of the molecules are within the recommended values. The binding free energy was calculated using PRIME MM-GB/SA studies. From the ligandsA38,A13,A23,A18,A7,A48andA46with significant Glide scores may produce significant COVID-19 activity for further development. CompoundA38was subjected to MD simulation at 100 ns to study the dynamic behaviour of protein-ligand complex. Communicated by Ramaswamy H. Sarma