Anticholinesterase and antioxidant activities of novel heterocyclic Schiff base derivatives containing an aryl sulfonate moiety

In this research, nine novel heterocyclic Schiff base derivatives (10-18) bearing an aryl sulfonate moiety were designed, synthesized for the first time, and characterized. Then, their inhibitory effects on acetyl- and butyrylcholinesterase (AChE and BChE) were investigated in vitro conditions. Moreover, their antioxidant activities were examined by DPPH and ABTS methods. The results indicated that some of the tested molecules had varying enzyme inhibition and antioxidant activities. We determined that compounds 8, 9, 14, 17, and 18 indicated inhibitory effects with IC50 values ranging from 89.30 to 111.28 mu M against BChE, respectively compared to standard compound galanthamine (IC50 = 125.88 mu M). On the other hand, of the molecules tested, only compound 5 (IC50 = 36.64 mu M) displayed inhibitory activity higher than galanthamine against AChE. In DPPH assay, compounds 15 (IC50 = 161.93 mu M), 16 (IC50 = 191.76 mu M) and 17 (IC50 = 107.55 mu M) showed higher antioxidant activity than BHT (IC50 = 203.50 mu M). On the other hand, it was determined in ABTS assay that Schiff bases 10-17 (except for compound 18) indicated higher antioxidant activity than BHT.