Design, synthesis and identification of novel molecular hybrids based on naphthoquinone aromatic hydrazides as potential trypanocide and leishmanicidal agents

In pursuit of potential agents to treat Chagas disease and leishmaniasis, we report the design, synthesis, and identification novel naphthoquinone hydrazide-based molecular hybrids. The compounds were subjected to in vitro trypanocide and leishmanicidal activities. N’-(1,4-Dioxo-1,4-dihydronaphthalen-2-yl)-3,5-dimethoxybenzohydrazide (13) showed the best performance against Trypanosoma cruzi (IC₅₀ 1.83 µM) and Leishmania amazonensis (IC₅₀ 9.65 µM). 4-Bromo-N’-(1,4-dioxo-1,4-dihydronaphthalen-2-yl)benzohydrazide (16) exhibited leishmanicidal activity (IC₅₀ 12.16 µM). Regarding trypanocide activity, compound 13 was low cytotoxic to LLC-MK2 cells (SI = 95.28). Furthermore, through molecular modeling studies, the cysteine proteases cruzain, rhodesain and CPB2.8 were identified as the potential biological targets.

Key words
Neglected diseases; Trypanocide activity; Leishmanicidal activity; Lawsone; Naphthoquinone hydrazide hybrids