Figure 13

Screening of new derivatives for inhibition of HuNoV (GII.4) RdRp activity. (A) The inhibitory effects of 8 compounds were examined against norovirus RdRp activity using a fluorescent activity assay at 20 μM. Compounds 53 and 54 exhibited almost 60% inhibition. PPNDS (green bar) and compound 1 (black bar) were used as positive controls. Percentage of inhibition was normalised to control DMSO (red bar). The mean values of triplicate datasets with standard error of the mean are shown. (B) A counter-screen-gel- shift assay was used to confirm norovirus RdRp inhibitory activity of 53, the most active compound identified in panel (A). PE44-NoV RNA templates (32 nucleotides) were extended (44 nucleotides) by the RdRp in the absence of any test compounds (0.5% DMSO [vol/vol] negative control) or with test compounds at a fixed concentration of 100 μM. PPNDS and compound 1 and were used as positive controls (100 μM) to demonstrate complete inhibition, and no RdRp was used as a negative control. Full-length gels are presented in Supplementary Fig. S4.