New heterocyclic compounds: Synthesis and antitrypanosomal properties

Area of Science:

• Medicinal Chemistry
• Parasitology
• Drug Discovery

Background:

• Trypanosoma brucei gambiense is the causative agent of human African trypanosomiasis (sleeping sickness).
• Development of novel therapeutic agents is crucial due to emerging drug resistance and limited treatment options.

Purpose of the Study:

• To synthesize and evaluate novel quinoline, quinolone, and benzimidazole derivatives for antitrypanosomal activity.
• To assess the in vitro and in vivo efficacy of these compounds against Trypanosoma brucei gambiense.

Main Methods:

• Chemical synthesis of three new series of heterocyclic compounds.
• In vitro evaluation of antitrypanosomal activity using IC50 assays.
• In vivo efficacy testing in infected mouse models.

Main Results:

• Ferroquine (FQ) and ruthenoquine (RQ) analogs exhibited potent in vitro activity (IC50 ≈ 0.1 μM) but failed in vivo.
• Other heterocyclic derivatives displayed in vitro activity with IC50 values ranging from 0.8 to 34 μM.
• A fluoroquinolone derivative (compound 2) demonstrated a survival benefit of 8 days in vivo after a single dose.

Conclusions:

• The synthesized quinoline, quinolone, and benzimidazole derivatives show potential as leads for antitrypanosomal drug discovery.
• Further structure-activity relationship studies and pharmacomodulations are warranted, particularly for the fluoroquinolone series.