The following are available online at https://www.mdpi.com/1999-4915/12/10/1092/s1, Figure S1: The chemical structure of tenofovir disoproxil and schematic representation of its metabolic bioactivation, Figure S2: The chemical structure of tenofovir alafenamide and schematic representation of its metabolic bioactivation, Figure S3: The chemical structure of AT-527 and schematic representation of its metabolic bioactivation, Figure S4: The chemical structure of danoprevir and maraviroc, Figure S5: The chemical structures of three natural products that are currently being tested against COVID-19, Figure S6: The chemical structures of various agents with potential antiviral activity attributed to various mechanisms.