In vitro activity of chloroquine, the two enantiomers of chloroquine, desethylchloroquine and pyronaridine against Plasmodium falciparum

A 48 h in vitro test was conducted to compare the susceptibility of two strains of Plasmodium falciparum to chloroquine, the two enantiomers of chloroquine, desethylchloroquine and the new antimalarial drug pyronaridine. The five compounds similarly inhibited the chloroquine sensitive strain. However, desethychloroquine was less active and pyronaridine was much more active than chloroquine and its enantiomers against the chloroquine resistant strain.