Structure-activity relationship of chalcones and related derivatives as ligands for detecting of ƒÀ-amyloid plaques in the brain.
A series of novel chalcones and their related derivatives were synthesized and evaluated as ƒÀ-amyloid imaging probes. In the structure-activity relationship of binding affinities to synthetic AƒÀ(1-42) aggregates, compound 14 displayed the highest binding affinity in vitro. ƒÀ-Amyloid plaques in the Alzheimer's model mouse brain were visualized with 14. In biodistribution studies using normal mice, [125I]14 showed good brain uptake (2.56% ID/g, 2min postinjection) and rapid washout from the brain (0.21% ID/g, 60min postinjection). These results suggest that [125I]14 should be further investigated as a potentially useful ƒÀ-amyloid imaging probe.