Biological and In Silico Evaluation of Novel Methoxyphenol–1,2,3-Triazole Hybrids as Multifunctional Anti-Alzheimer's and Anticancer Agents

Abstract

The development of multifunctional small molecules capable of simultaneously modulating multiple pathological pathways represents a rational strategy in medicinal chemistry for complex disorders such as Alzheimer's disease (AD) and cancer. Herein, a novel series of methoxyphenol-based 1,2,3-triazole hybrids (5a–h) was designed and synthesized via Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC). All derivatives were fully characterized by FT-IR, ¹H/¹³C NMR spectroscopy, and elemental analysis. Biological evaluation encompassed in vitro antioxidant screening (DPPH•, ABTS•⁺, and CUPRAC), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition (modified Ellman method), and antiproliferative activity against the PC3 prostate cancer cell line using HDF-1 healthy fibroblasts as a selectivity control. Compound 5c proved the most potent AChE inhibitor (IC₅₀ = 1.44 ± 0.33 μM; SI = 16.77), while 5h exhibited preferential BuChE inhibition (IC₅₀ = 11.40 ± 1.25 μM). Enzyme kinetic studies confirmed a mixed-type inhibition mechanism for both lead compounds, suggesting dual-site engagement within the cholinesterase gorge. In the antiproliferative assay, 5e and 5c surpassed the reference drug methotrexate (IC₅₀ = 4.42 ± 0.15 μM) with IC₅₀ values of 3.57 ± 0.11 μM and 3.89 ± 0.20 μM, respectively, alongside favorable selectivity over healthy fibroblasts. In silico ADMET profiling confirmed drug-likeness for all derivatives, and DFT calculations at the B3LYP/6-311++G(d,p) level provided electronic rationale for observed reactivity trends. Molecular docking against human AChE (PDB: 4EY7) and BuChE (PDB: 4BDS) rationalized key stabilizing interactions including π–π stacking with Trp86/Trp286 and hydrogen bonding with active-site residues. Collectively, these findings identify the methoxyphenol–triazole scaffold as a promising lead platform warranting further optimization for multitarget therapeutic applications in neurodegenerative and oncological disorders.