RESULTS AND DISCUSSION
Figure 1 illustrates the IC50s for the tested alkylamides, spilanthol and UDA on P. falciparum in vitro. For the Brazilian mildy chloroquine resistant strain PFB (Figure 1A), the IC50s for spilanthol and UDA are 16.5 and 41.4 μg/mL, respectively. While for the Thailanese chloroquine resistant strain K1 (Figure 1B), the effect of the alkylamides is significantly greater, with IC50s of 5.8 and 16.3 μg/mL, respectively.