English: 3D molecular structure (Jmol) of remdesivir (RDV). RDV is an antiviral compound with a broad spectrum of antiviral activities (e.g. SARS-CoV and MERS-CoV) and currently being used in clinical trials against the novel coronavirus COVID-19 to test its clinical efficiacy. Chemical formula C27H35N6O8P. Legend: carbon atom grey; hydrogen, white; nitrogen, blue; oxygen, red; phosphorous, yellow. IUPAC name (2S)-2-{(2R,3S,4R,5R)-[5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxy-tetrahydro-furan-2-ylmethoxy]phenoxy-(S)-phosphorylamino}propionic acid 2-ethyl-butyl ester. The molecule contains several aromatic rings with delocalized π bonding. RDV is a prodrug which is metabolized to the nucleoside analog GS-5734 that targets viral RNA polymerase. An effective nucleoside analog must evade proofreading (by 3′-5′ exoribonuclease) to successfully interfere with CoV RNA synthesis for better clinical efficiacy.