SP-471P is a potent inhibitor of dengue virus (DENV) protease, exhibiting half-maximal effective concentrations (EC50) of 5.9 µM for DENV1, 1.4 µM for DENV2, 5.1 µM for DENV3, and 1.7 µM for DENV4, with a cytotoxic concentration (CC50) greater than 100 µM. Additionally, SP-471P effectively reduces DENV viral RNA synthesis [1].