Benzoic acid derivatives with trypanocidal activity: Enzymatic analysis and molecular docking studies toward trans-sialidase

Chagas, or American trypanosomiasis, remains an important public health problem in developing countries. In the last decade, trans-sialidase has become a pharmacological target for new anti-Chagas drugs. In this work, the aims were to design and find a new series of benzoic acid derivatives as trans-sialidase (TS) inhibitors and anti-trypanosomal agents. Three compounds (14, 18, and 19) sharing a para-aminobenzoic acid moiety showed more potent trypanocidal activity than the commercially available drugs nifurtimox and benznidazole in both strains: the lysis concentration of 50% of the population (LC₅₀) was <0.15 μM on the NINOA strain, and LC50 < 0.22 μM on the INC-5 strain. Additionally, compound 18 showed a moderate inhibition (47%) on the trans-sialidase enzyme and a binding model similar to DANA (pattern A).