In comparison, approved antimalarial mefloquine used as positive control in the same experiment displayed an EC50 of 0.048 µM. Secondly, because the seed molecule from which the two molecules were derived is active against Plasmodium vivax PI(4)K (PvPI(4)K), we investigated whether the proposed molecules recapitulated this mechanism of action or inherited a divergent mechanism of action from other molecules in the training set. In a biochemical PvPI(4)K assay, compounds 1 and 2 were active with EC50 values of 0.0028 µM and 0.0016 µM, respectively (Figure ). PvPI(4)K positive control KDU731 displayed an EC50 of 172 pM within the same experiment. Lastly, we investigated whether there were potential off-targets associated with cytotoxicity.