Design, Synthesis, and X-ray Characterization of Benzohydrazide Derivatives as Cholinesterase Inhibitors for the Treatment of Alzheimer’s Disease: An Experimental and Computational Approach to Biological Activity

In this study, a series of new benzohydrazide derivatives (1a-i) were synthesized, and characterized as potential cholinesterase inhibitors for use in the treatment of Alzheimer’s disease (AD). The inhibitory activities of the synthesized compounds against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes were evaluated using in vitro and in silico methods. IC50 values for AChE inhibition ranged from 29.50 to 46.21 nM, with compound 1c exhibiting the highest inhibitory potential at an IC50 of 29.50 nM. For the BChE enzyme, the strongest effect was observed with compound 1d at an IC50 of 55 nM. The synthesized derivatives exhibited higher inhibitory potential compared to the reference tacrine (IC50: 58.73 nM for AChE and 187.30 nM for BChE) against cholinesterase enzymes through both competitive and non-competitive inhibition mechanisms. Molecular docking (ΔG: -10.67 to -9.95 kcal/mol for AChE; -9.80 to -8.69 kcal/mol for BChE) and 100 ns molecular dynamics simulations supported the binding affinities and indicated the dynamic stability of the enzyme-inhibitor complexes, in agreement with the experimental inhibition data. In silico ADMET profiling indicated favourable drug-likeness and high predicted gastrointestinal absorption and blood-brain barrier permeability (TPSA 41.46-61.69 A2), and structural alert screening returned no PAINS matches. The findings suggest that these derivatives may serve as promising lead compounds for further investigation as potential cholinesterase inhibitors relevant to AD, pending experimental cytotoxicity evaluation.