FIG. 3.

Effects of candidate compounds on the viabilities of sorbitol-lysed synchronized P. falciparum merozoites in tissue culture. P. falciparum cultures were exposed to various concentrations of a candidate compound for 48 h before the degree of parasite viability was determined by an LDH assay (see Materials and Methods). The percentage of the control activity was determined by comparing the values obtained in treated wells to those obtained in untreated wells. The datum points indicate the results obtained with compound 4 (•), compound 7 (▾), no treatment (▿), and compound 1 (○), with lines of best fit shown. Compounds 4 and 7 had IC₅₀s greater than 1 mg/ml. The IC₅₀ of compound 1 was 0.2 μM.