In vitro antiprotozoal and cytotoxic activities of some alkaloids, quinones, flavonoids, and coumarins.

Twenty-six pure plant-derived compounds including alkaloids, quinones, flavonoids, and coumarins, obtained from five species of Central American plants associated with traditional uses, were tested in vitro for antiprotozoal and cytotoxic activities. The quinone, 1-acetyl-benzoisochromanquinone displayed significant antiprotozoal activity against Leishmania donovani promastigotes and amastigotes, Trypanosoma cruzi amastigotes, and T. brucei brucei bloodstream form trypomastigotes, with IC50 values of 2.32, 1.98, 6.60, and 0.65 muM, respectively. The quinones benzo[g]isoquinoline-5,10-dione had an IC50 value of 4.2 muM against Plasmodium falciparum and 1-hydroxybenzoisochromanquirione an IC50 value of 3.3 muM against T. b. brucei trypomastigotes. The remaining compounds were either weakly active or inactive.