In Search for Effective and Safe Drugs Against SARS-CoV-2: Part III] the Electronic Factors of Remdesivir and the Naturally Extracted Aspirochlorine Drugs

This report is associated with an ongoing coronavirus outbreak. We selected Remdesivir (used in the treatment of Ebola) and Aspirochlorine (a natural product found in Aspergillus oryzae), and their binding to specific peptide sequences of the coronavirus S-protein: ACE2 interface-drug binding adduct were calculated. The stable intermolecular adducts between the chosen drug molecules with the S protein and ACE2 result in limited host-virus interactions. The electrophilicity and nucleophilicity indices of the drugs showed that both drugs act as electron sinks to shield ACE2 from interacting with the S protein. Aspirochlorine acts as an electron acceptor (electrophile) toward both individual targets, the ACE2, and S proteins (nucleophiles). Aspirochlorine electronically shields ACE2 from the interaction with S protein by sinking the electronic charge of the S protein. The electrophilicity and nucleophilicity parameters of Remdesivir were higher than those of ACE2, and both molecules were bound via hydrogen bonding intermolecular interactions without intermolecular electron transfer. Remdesivir also shields ACE2 from the S protein. The results obtained strongly suggest the beneficial use of both drugs. The results reported indicate that the association of remdesivir with the target proteins was exothermic, while it was endothermic in the case of Aspirochlorine. Both drugs offer protection and/or treatment against the coronavirus S-protein COVID-19.