Design, Synthesis, and Structure-Activity Relationship of N-Arylnaphthylamine Derivatives as Amyloid Aggregation Inhibitors

Dyes like CR are able to inhibit the aggregation of A beta fibrils. Thus, a screening of a series of dyes including ABBB (1) was performed. Its main component 2 tested in an in vitro assay (i.e., ThT assay) showed good potency at inhibiting fibrils association. Congeners 4-9 have been designed and synthesized as inhibitors of A beta aggregation. A nurnber of these newly synthesized compounds have been found to be active in the ThT assay with IC50 of 1-57.4 mu M. The most potent compound of this series, 4k, showed micromolar activity in this test. Another potent derivative 4q (IC50 = 5.6 mu M) rapidly crossed the blood-brain barrier, achieving whole brain concentrations higher than in plasma. So 4q could be developed to find novel potent antiaggregating beta A agents useful in Alzheimer disease as well as other neurological diseases characterized by deposits of amyloid aggregates.