Abstract
Objective: In this study we aimed to synthesize some hydrazone derivatives of thiazole and to evaluate their anticholinesterase activities.
Method: Pyrrole-2-carboxaldehydes were reacted directly with thiosemicarbazide in ethanol and then obtained thiosemicarbazones were condensed with alpha-bromoacetophenone derivatives (Hantzsch reaction) to give 1-substituted pyrrole-2-carboxaldehyde (4-(4-substituted phenyl)-1,3-thiazol-2-yl) hydrazones. The structures of the obtained compounds were elucidated by using IR, 1H-NMR and FAB+-MS spectral data and elemental analyses results. In the pharmacological studies, anticholinesterase activities of these compounds have been evaluated by using modified Ellman's spectrophotometric method.
Results: The compound (1) can be identified as the most active anticholinesterase molecule due to its inhibitory effect on acetylcholinesterase with inhibition percentages of 64.10 (1 mM) and 33.00 (0.1 mM) % and also IC50 value of 0.59 mM.
Conclusion: The substitutions on phenyl ring at para position and at first position of pyrrole ring have negatively affected anticholinesterase activity.