Synthesis, characterization and determination of antioxidant activities of some new hydrazon compounds

In this research, some new heterocyclic hydrazone compounds bearing an aryl sulfonate moiety (2a-i) were facilely synthesized for the first time and elucidated by some spectroscopic techniques (FT-IR, 1H- and 13C NMR). The inhibitory potentials of all synthesized molecules on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase enzymes were investigated. Also, DPPH, ABTS and CUPRAC antioxidant activities of all molecules were examined. In BChE assay, it was determined that 2-formylphenyl 4-chlorobenzenesulfonate (1a) (IC50=10.45 μM), 5-(diethylamino)-2-formylphenyl 4-chlorobenzenesulfonate (1h) (IC50=10.12 μM), and 1-((2-nicotinoylhydrazono)methyl)naphthalen-2-yl 4-chlorobenzenesulfonate (2i) (IC50=9.89 μM) were found to be more effective than the standard compound galanthamine and donepezil. In DPPH assay, 2-((2-nicotinoylhydrazono)methyl)phenyl 4-chlorobenzenesulfonate (2a) (IC50=361.03 μM) and 5-methoxy-2-((2-nicotinoylhydrazono)methyl)phenyl 4-chlorobenzenesulfonate (2e) (IC50=348.9 μM) indicated the highest antioxidant activities. On the other hand, the molecular electrostatic potential (MEP) maps of compounds 1a, 1h, 2i and galanthamine molecules were investigated.