Synthesis, bioassay and molecular docking of novel pyrazole and pyrazolone derivatives as acetylcholinesterase inhibitors

Abstract

- Synthesis of pyrazole and pyrazolone derivatives ( 1 ), ( 3 ) and ( 4 ). - In silico study of pyrazole and pyrazolone derivatives as (AChE) inhibitors. - In vitro (AChE) inhibition study of pyrazole and pyrazolone ( 1 ), ( 3 ) and ( 4 ). - pyrazolone derivative ( 1) exhibited good inhibitory activity against AchE. - pyrazolone derivative ( 1) has potential for in vivo anti-Alzheimer evaluations. Pyrazole and pyrazolone derivatives have attracted growing interest over the years because of their versatile applications in various fields. In this work, we describe the condensation of thiosemicarbazide and tosylhydrazine with ethyl acetoacetate using different catalysis. Docking study was performed for the reference compound rivastigmine and the prepared pyrazole and pyrazolones against human acetylcholinesterase (AChE). Based on the binding pose, compound ( 1 ) and ( 3 ) were occupying the site located in the deep cavity of AChE and rivastigmine was occupied the central active site cavity of AChE. While, the compound ( 4 ) was occupied the exterior active site cavity of the enzyme. The detailed interactions between the rivastigmine and the synthesized compounds and human acetylcholinesterase were determined and showed that the AChE- compound ( 1 ) complex was established several interactions with catalytic residues (His 447 and Ser 203) and the critical residue for the inhibition of the human enzyme (Tyr 337). Thus, this compound was predicted to be the most potent compound. The in vitro Acetylcholinesterase (AChE) inhibition studies showed that compound ( 1 ) has a good inhibitory activity against AChE and this activity is similar to that of rivastagmine with an IC 50 value of 0.38 ± 0.019 mg/mL (p < 0.05) and 0.36 ± 0.018 mg/mL (p < 0.05), respectively. These findings confirmed the in silico results and suggest the possibility of using compound ( 1 ) as anti-Alzheimer drug.