Blocking activity of four derivatives against in vitro conversion of PrP^C by RT-QuIC. The conversion of PrP^C was observed in the wells treated with (A) BMD42-2908, (B) BMD42-2909, (C) BMD42-2910, and (D) BMD42-2914 at concentrations of 1.2, 2.5, 5, 10, and 20 μM. RT-QuIC reaction buffer was mixed with the brain homogenate of sCJD patient and each compound, and then it was incubated for 72 h at 44°C, with intermittent shaking. Each condition was performed in quadruplicate. The mean ThT fluorescence values were plotted against time.