Fig. 5

Secondary screen and evaluation of RBF98 analogs. A A total of 34 compounds that inhibited Luciferase signal by ≥ 50% compared to control were identified. Luciferase activity results are expressed relative to values obtained in the presence of vehicle controls. Percentage inhibition was calculated and plotted in a scatter plot, n = 3 biological replicates performed Mean ± SEM. B Structures of RBF197, RBF203, and RBF208, potent candidate inhibitors. C Representative plots of percentage inhibition values of luciferase activity on the treatment of RBF 197, RBF203, and RBF208 at 0.1, 1, and 10 µM in eIF4A1-3X-Luciferase in Hek293T/17 cell lines for 24 h (n = 3). Statistical analysis was performed using one-way ANOVA followed by Bonferroni’s correction analysis. ^ap < 0.05; ^cp < 0.001, ^dp < 0.0001 vs DMSO control groups, ^αp < 0.05, ^βp < 0.001, ^¥p < 0.0001 vs 10 μM treatment groups. D Concentration–response curves of percentage inhibition of human eIF4A1 in-vitro activity on the treatment of RBF197, RBF203, and RBF208, compared to DMSO control by measurement of inorganic phosphate released (SensoLyte Kit). IC₅₀ values observed were 55.2, 208.8, and 74.1 pM, respectively. E Hill coefficient values for the concentration–response curves