Decamethoxin virucidal activity: in vitro and in silico studies

The data on the representative of decamethoxin short-term action on infectious bronchitis virus (IBV) strain H120 used as a human-safe model of SARS-CoV-2 virus are presented. The viral activity was estimated with the use of inverted microscope PrimoVert (Germany) by destructive effect on BHK21 fibroblastic cell line. In vitro results demonstrated that decamethoxin (100 μg/ml) completely inactivated IBV coronavirus strain at exposure of 30 sec and more. At the lowest decamethoxin exposure of 10 sec the antiseptic virucidal activity was 33% and 36% of control at 24 and 48 h of cultivation respectively. Molecular docking analysis indicated the significant similarity of IBV and SARS-CoV-2 main protease (Mpro) structure. Docking studies of decamethoxin interaction with IBV Mpro and SARS-CoV-2 Mpro active centers demonstrated the ligand-protein complexes formation with the estimated binding energy of -8.6, -8.4 kcal/mol and key amino acid residues ASN26, GLY141, GLU187, GLU164, THR24, THR25, ASN142, GLY143, CYS145, HIS164 and GLU166. Keywords: decamethoxin, IBV strain H120, main protease, mole­cular docking, QAC, SARS-COV-2, virucidal activity