A viral RNA-dependent RNA polymerase (RdRp) inhibitor that acts as a non-obligate RNA chain terminator; exhibits broad-spectrum antiviral activity against negative-sense RNA viruses representing the Filoviridae, Arenaviridae, Bunyaviridae,Orthomyxoviridae,Picornaviridae and Paramyxoviridae families, and positive-sense RNA viruses of the Flaviviridae and Coronaviridae families (EC50=5-60 uM).
