Synthesis and biological evaluation of 2,3-dihydroimidazo[1,2-a]benzimidazole derivatives against Leishmania donovani and Trypanosoma cruzi.

A high-throughput (HTS) and high-content screening (HCS) campaign of a commercial library identified 2,3-dihydroimidazo[1,2-a]benzimidazole analogues as a novel class of anti-parasitic agents. A series of synthetic derivatives were evaluated for their in vitro anti-leishmanial and anti-trypanosomal activities against Leishmania donovani and Trypanosoma cruzi, which have been known as the causative parasites for visceral leishmaniasis and Chagas disease, respectively. In the case of Leishmania, the compounds were tested in both intracellular amastigote and extracellular promastigote assays. Compounds 4 and 24 showed promising anti-leishmanial activity against intracellular L. donovani (3.05 and 5.29 μM, respectively) and anti-trypanosomal activity against T. cruzi (1.10 and 2.10 μM, respectively) without serious cytotoxicity toward THP-1 and U2OS cell lines.