ACHE and neuroblastoma: Most of these compounds demonstrated strong and selective inhibition towards AChE and MAO B. Notably, the four-carbon-atom linker provided compound C21a exhibiting well-balanced dual inhibitory activity against both AChE (IC50 = 0.11 μM, mixed-type inhibition) and MAO B (IC50 = 0.10 μM, reversible and competitive binding mode) along with good BBB penetration in PAMPA experiments and negligible toxicity in SH-SY5Y neuroblastoma cells.