Character of Frontier Orbitals of Antiviral Drugs: Candidate Drugs against Covid-19

We performed density functional theory (DFT) calculations for ribonucleotides and active triphosphate metabolites of candidate drugs against Coronavirus disease 2019 (Covid-19). Frontier orbitals (highest occupied molecular orbital and lowest unoccupied molecular orbital) at optimized structure of each molecule were obtained. T-705RTP (active triphosphate metabolite of favipiravir) and cytidine triphosphate (CTP) have similar shapes of frontier orbitals. We also obtained similar shapes of frontier orbitals among dihydroxy GS-441524 triphosphate (GS-441524 is an active triphosphate metabolite of remdesivir) and adenosine triphosphate (ATP). From a theoretical viewpoint, we suggest T-705RTP is a CTP analogue and dihydroxy GS-441524 triphosphate is an ATP analogue.