Synthesis of novel 6-substituted-3-formyl chromone derivatives as anti-leishmanial agents and their possible mechanism of action in Leishmania donovani

Eleven new compounds, including the hydrazones 4a-h , pyrazole 5 , and pyrazole-oximes 7b-c , were syn-thesized by condensation reaction between 6-substituted (-H,-Me,-F) 3-formylchromones 1a-c with N- substituted hydrazines 2a-d and hydroxylamine hydrochloride 3 . The synthesized compounds were eval-uated for their in vitro antileishmanial activity to determine the IC50 values. Compounds 4b, 4c and 4e exhibited the strongest antileishmanial activity with IC50 values between 1.6 - 4.7 mu m. A plausible mech-anism of action is proposed for the antileishmanial activity of the above-mentioned compounds. We also studied the effect of these three compounds on macrophages, which represent the mammalian host-cell. The results obtained on this system were about one order of magnitude larger when compared to those of L. donovani, thus supporting these compounds potential as precursors of antileishmanial drugs. (c) 2023 Elsevier B.V. All rights reserved.