Synthesis of Novel N-Acylhydrazones Derived from 3,5-Dinitrobenzohydrazide and Evaluation of Their Anticholinesterase and Antioxidant Activities

Objective: In this study, it was aimed to determine the antioxidant activities and enzyme inhibition properties of newly synthesized N- acylhydrazone compounds ( IIIa–IIIp ) bearing an aryl sulfonate moiety. Methods: For this purpose, a series of hydrazone derivatives based on 3,5-dinitrobenzohydrazide ( I ) was synthesized for the first time and characterized by spectrometric methods (FT-IR, 1 H NMR and 13 C NMR) and elemental analysis. In vitro anticholinesterase activities of novel hydrazone derivatives were evaluated against acetyl- and butyrylcholinesterase (AChE and BChE) at 200 µM concentration. Moreover, the antioxidant potentials of the same molecules were determined by 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and cupric ion reducing antioxidant capacity (CUPRAC) assays. Results: The obtained results displayed that some of the tested hydrazone compounds had varying enzyme inhibition and antioxidant activities. Discussion: In enzyme inhibition studies, N ′-[2-{[4-fluorobenzensulfonyl]oxy}benzylidene]-3,5-dinitrobenzohydrazide ( IIIb ) with inhibition value 77.13 ± 0.14% showed the closest activity to the standard compound galanthamine with inhibition value 78.14 ± 0.65%. Compared to DPPH and ABTS assays, all of the molecules tested in CUPRAC assay showed antioxidant activities. The molecules tested in CUPRAC assay did not show as much activity as standard molecules (BHA, BHT and α-TOC). Conclusions: Compounds N ′-[4-{[4-fluorobenzensulfonyl]oxy}benzylidene]-3,5-dinitrobenzohydrazide ( IIIf ) and N ′-[4-{[4-methoxybenzensulfonyl]oxy}benzylidene]-3,5dinitrobenzohydrazide ( IIIh ) in this assay were determined to be the most active molecules.