nzenesulfonamide moiety in the N-linker between both adenosines, that blocks the activity of SARS-CoV nsp14 at the submicromolar concentration in the same range than sinefungin but with a significant specificity. Thermal shift assays and molecular modeling indicate that the inhibitory activity is likely due to the binding of 13 to both SAM and mRNA binding pockets of nsp14. It is quite interesting to note that all residues of SARS-CoV nsp14 involved in the binding of 13 are fully conserved in the SARS-CoV-2 nsp14 protein (Fig. S1, Supporting Information). Indeed, the genome sequence of SARS-CoV-2 nsp14