Synthesis and comprehensive evaluation of new spiro-dimedone derivatives as cholinesterase and ?-glycosidase inhibitors: X-ray crystallography, in vitro assays, and integrated molecular docking, dynamics, and ADME analysis

Abstract

A series of newly developed spirodimedone derivatives have demonstrated potent multi-target inhibition of cholinesterases and alpha-glucosidase. Among the synthesized compounds, derivative 4b emerged as the most effective dual cholinesterase inhibitor, exhibiting IC50 values of 32.02 +/- 0.57 & micro;M for acetylcholinesterase (AChE) and 3.81 +/- 0.10 & micro;M for butyrylcholinesterase (BChE), significantly outperforming the reference drug galantamine. Compound 4d demonstrated the most potent alpha-glucosidase inhibition (IC50 = 102.57 +/- 0.85 & micro;M), surpassing the activity of acarbose, and also exhibited the highest metal chelation capacity. Structure-activity relationship analysis revealed that substituent-dependent electronic and steric effects governed enzyme selectivity along the spirodimedone skeleton. Molecular docking and molecular dynamics simulations, in strong agreement with in vitro data, confirmed that the most active compounds bind stably to key catalytic and peripheral enzyme sites. These findings reveal spirodimedone derivatives as promising multi-target ligands capable of simultaneously modulating cholinergic dysfunction, carbohydrate metabolism, and metal-related oxidative stress. This study provides a mechanistic perspective and a rational framework for further optimization of multifunctional therapeutics targeting interconnected neurodegenerative and metabolic disorders.