FIG. 4.

G25 in vitro antimalarial activity as a function of the parasite stage. P. falciparum-infected RBC were synchronized with 5% d-sorbitol as described in the legend to Fig. 3. Drug was added for 4 h when the parasites were in the ring (•), trophozoite (▴), or schizont (▪) stage. At the end of the incubation, media were replaced by fresh complete medium, and the suspensions were further cultured for 20 h before the addition of [³H]hypoxanthine.