Antiparasitic activity of marine pyridoacridone alkaloids related to the ascididemins

A series of pyridoacridone alkaloids, including the marine alkaloid ascididemin were tested in vitro for antiparasitic activity against P. falciparum (K1, NF54), L. donovani, T. cruzi, T. b. rhodesiense and two mammalian cell lines (L6, RAW 264.7). Most compounds showed high antiplasmodial activity, moderate antileishmanial activity against both extra- and intracellular forms, and significant trypanocidal effects against T. cruzi and T. b. brucei. However, when tested against mammalian cell lines, most of the compounds were also toxic for macrophage-like RAW 264.7 cells and skeletal muscle myoblast L6 cells. Correlations between molecular structures and antiparasitic activity are discussed in detail. Specific compounds are illustrated with emphasis on their potential as new antiparasitic drug leads.