Design, Synthesis, and Biological Evaluation of Novel Multitarget 7-Alcoxyamino-3-(1,2,3-triazole)-coumarins as Potent Acetylcholinesterase Inhibitors.

Background: Multitarget-directed ligands (MTDLs), particularly those combining cholinesterase inhibition with additional mechanisms, are promising candidates for Alzheimer's disease (AD) therapy. Based on our previous identification of a dual-active coumarin derivative, we designed a new series of 7-alkoxyamino-3-(1,2,3-triazole)-coumarins. Methods: These compounds were synthesized by a new Sonogashira protocol and evaluated for AChE and BChE inhibition, enzymatic kinetics, molecular docking, neurotoxicity in SH-SY5Y cells, neuroprotection against H₂O₂-induced oxidative stress, and additional interactions with H₃R and MAOs. Results: All derivatives inhibited AChE with IC₅₀ values of 4-104 nM, displaying high selectivity over BChE (up to 686-fold). Kinetic and docking studies indicated mixed-type inhibition involving both CAS and PAS. The most potent compounds (1h, 1j, 1k, 1q) were non-neurotoxic up to 50 µM, while 1h and 1k also showed neuroprotective effects at 12.5 µM. Selected derivatives (1b, 1h, 1q) demonstrated multitarget potential, including H₃R affinity (K_i as low as 32 nM for 1b) and MAO inhibition (IC₅₀ of 1688 nM for 1q). Conclusions: This series of coumarin-triazole derivatives combines potent and selective AChE inhibition with neuroprotective and multitarget activities, highlighting their promise as candidates for AD therapy.