Design, synthesis and evaluation of genistein-O-alkylbenzylamines as potential multifunctional agents for the treatment of Alzheimer's disease.

A series of genistein derivatives with carbon spacer-linked alkylbenzylamines were designed, synthesized and tested as multifunctional agents for the treatment of Alzheimer's disease (AD). The results showed that most of these compounds exhibited good acetylcholinesterase (AChE) inhibitory activity, with moderate-to-good anti-oxidative activity. Specifically, compounds 10b, 19d and 25d exhibited significant inhibition of β-amyloid (Aβ) aggregation and exhibited metal chelating properties. In particular, 25d inhibited: self-induced Aβ₁₋₄₂ aggregation, Cu(2+)-induced Aβ₁₋₄₂ aggregation, and human AChE-induced Aβ₁₋₄₀ aggregation by 35%, 77.8%, and 36.2%, respectively. Moreover, both kinetic analysis of AChE inhibition and the molecular modeling study suggested that 25d binds simultaneously to catalytic active site and peripheral anionic site of AChE. More importantly, compound 25d disassembled the well-structured Aβ fibrils generated by Cu(2+)-induced Aβ aggregation by 72.1%. Furthermore, the step-down passive avoidance test showed this compound significantly reversed scopolamine-induced memory deficit in mice. These results suggest that 25d may be a promising multifunctional agent for AD treatment.