Design, synthesis and evaluation of thiazole derivatives as cholinesterase inhibitors and antioxidant agents

Abstract

This study aimed to synthesize 11 new potential anti-Alzheimer agents via cholinesterase inhibition and antioxidant activity. In order to obtain new thiazole derivatives, first the reaction of thiosemicarbazide with 5-methyl-thiophene-2-carbaldehyde was performed, then the cyclization of the obtained compounds with 2-bromoacetophenone derivatives was performed and the target compounds (2a-2k) were obtained. The acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzyme inhibitory effects and antioxidant properties of newly synthesized thiazole derivatives were evaluated. According to cholinesterase inhibition assay, all synthesized compounds were weak inhibitors of AChE and BuChE. Generally, compounds were more effective against AChE than BuChE. Among the compounds, compound 2e has the highest AChE inhibition with a percentage inhibition value of 27.73 +/- 0.008 mu M. According to DPPH radical scavenging activity assay, compounds 2d and 2 g were most potent antioxidant agents with IC50 values of 29.12 +/- 0.008 mu M and 25.14 +/- 0.003 mu M, while that of gallic acid was found 29.48 +/- 0.014 mu M.