Unusual Cyclodextrin Derivatives as a New Avenue to Modulate Self- and Metal-Induced A beta Aggregation

Mounting evidence suggests an important role of cyclodextrins in providing protection in neurodegenerative disorders. Metal dyshomeostasis is reported to be a pathogenic factor in neurodegeneration because it could be responsible for damage involving oxidative stress and protein aggregation. As such, metal ions represent an effective target. To improve the metal-binding ability of cyclodextrin, we synthesized three new 8-hydroxyquinoline-cyclodextrin conjugates with difunctionalized cyclodextrins. In particular, the 3-difunctionalized regioisomer represents the first example of cyclodextrin with two pendants at the secondary rim, resulting in a promising compound. The derivatives have significant antioxidant capacity and the powerful activity in inhibiting self-induced amyloid-beta aggregation seems to be led by synergistic effects of both cyclodextrin and hydroxyquinoline. Moreover, the derivatives are also able to complex metal ions and to inhibit metal-induced protein aggregation. Therefore, these compounds could have potential as therapeutic agents in diseases related to protein aggregation and metal dyshomeostasis.