Structural Optimization and Biological Evaluation of Substituted Bisphenol A Derivatives as β-Amyloid Peptide Aggregation Inhibitors

The aggregation of A beta is a crucial step in the etiology of Alzheimer's disease. Our previous work showed that A beta undergoes alpha-helix/beta-sheet intermediate structures during the conformational transition, and an A beta aggregation inhibitor (1) was discovered by targeting the intermediates. Here, structure optimization toward compound 1 was performed and 34 novel derivatives were designed and synthesized. Nine compounds showed more effective inhibitory activity than the hit compound 1 in ThT fluorescence assay. Among them, compound 43 demonstrated more excellent inhibitory potency, which not only can suppress the aggregation of A beta but also can dissolve the preformed fibrils as shown by CD spectroscopy, PICUP and AFM assays. Cellular assay indicated that 43 has no toxicity to neuronal cells, moreover, can effectively inhibit A beta(1-42)-induced neutrotoxicity and increase the cell viability. Together, on the basis of these positive results, these novel chemical structures may provide a promising potential for therapeutic applications in AD and other types of neurodegenerative disorders.