Antiparasitic Lead Discovery: Toward Optimization of a Chemotype with Activity Against Multiple Protozoan Parasites.

Human African trypanosomiasis (HAT), Chagas disease, and leishmaniasis present a significant burden across the developing world. Existing therapeutics for these protozoal neglected tropical diseases suffer from severe side effects and toxicity. Previously, NEU-1045 () was identified as a promising lead with cross-pathogen activity, though it possessed poor physicochemical properties. We have designed a library of analogues with improved calculated physicochemical properties built on the quinoline scaffold of incorporating small, polar aminoheterocycles in place of the 4-(3-fluorobenzyloxy)aniline substituent. We report the biological activity of these inhibitors against (HAT), (Chagas disease), and (cutaneous leishmaniasis) and describe the identification of -(5-chloropyrimidin-2-yl)-6-(4-(morpholinosulfonyl)phenyl)quinolin-4-amine () as a promising inhibitor of proliferation and 6-(4-(morpholinosulfonyl)phenyl)--(pyrimidin-4-yl)quinolin-4-amine (), a potent inhibitor of proliferation with improved drug-like properties.