Several (sub)species of Trypanosoma are responsible for human African trypanosomiasis (HAT), Chagas disease, and Nagana. These (sub)species have different drug susceptibility profiles. This work reports several easily accessed quinolone hydrazides exhibiting sub-micromolar activities against multiple (sub)species of Trypanosoma. The lead compounds are not toxic to normal human cell lines, have optimal logD values (2–3), but suffer from poor aqueous solubility.

Abstract

Nagana and Human African Trypanosomiasis (HAT), caused by (sub)species of Trypanosoma, are diseases that impede human and animal health, and economic growth in Africa. The few drugs available have drawbacks including suboptimal efficacy, adverse effects, drug resistance, and difficult routes of administration. New drugs are needed. A series of 20 novel quinolone compounds with affordable synthetic routes was made and evaluated in vitro against Trypanosoma brucei and HEK293 cells. Of the 20 compounds, 12 had sub-micromolar potencies against the parasite (EC₅₀ values=0.051–0.57 μM), and most were non-toxic to HEK293 cells (CC₅₀ values>5 μM). Two of the most potent compounds presented sub-micromolar activities against other trypanosome (sub)species (T. cruzi and T. b. rhodesiense). Although aqueous solubility is poor, both compounds possess good logD values (2–3), and either robust or poor microsomal stability profiles. These varying attributes will be addressed in future reports.