Synthesis of novel quinine analogs and evaluation of their effects on Trypanosoma cruzi

Chagas disease is a tropical disease caused by the hemoflagellate protozoan Trypanosoma cruzi. There is no vaccine for Chagas disease and available drugs (e.g., benznidazole) are effective only during the acute phase, displaying a variable curative activity in the established chronic form of the disease. New leads with high efficacy and better toxicity profiles are urgently required. Materials & methods: A library of novel quinine derivatives was synthesized using Heck chemistry and evaluated against the various developmental forms of T. cruzi.

Several novel quinine analogs with trypanocidal activity have been identified with the para-nitro-substituted derivative displaying a submicromolar IC₅₀, which is 83-times lower than quinine and three-times lower than benznidazole. Transmission electron microscopy analysis demonstrated that these compounds induced a marked vacuolization of the kinetoplast of intracellular amastigotes and cell-derived trypomastigotes.