Monoquaternary ammonium derivatives inhibit growth of protozoan parasites

The phospholipid metabolism of Plasmodium falciparum-infected erythrocytes has been shown to be an effective pharmacological target for novel chemotherapy. Thirty-seven monoquaternary ammonium derivatives analogous to choline were screened for their potential antiprotozoal activity against P. falciparum and Leishmania braziliensis. Twenty-three compounds inhibited chloroquine resistant and sensitive P. falciparum strains with inhibitory concentrations ranging from 0.001 microM to 47 microM. Among the inhibitors were six compounds with nanomolar activity containing at least one ethyl group in the polar head and a hydrophobic alkyl chain with 10 to 14 methylene groups. Four compounds also exhibited in vitro antileishmanial properties in the micromolar range.