Aurones serve as probes of ƒÀ-amyloid plaques in Alzheimer's disease.
A novel series of aurone derivatives for in vivo imaging of ƒÀ-amyloid plaques in the brain of Alzheimer's disease (AD) were synthesized and characterized. When in vitro binding studies using AƒÀ(1-42) aggregates were carried out with aurone derivatives, they showed high binding affinities for AƒÀ(1-42) aggregates at the Ki values ranging from 1.2 to 6.8 nM. When in vitro plaque labeling was carried out using double transgenic mice brain sections, the aurone derivatives intensely stained ƒÀ-amyiloid plaques. Biodistribution studies in normal mice after i.v. injection of the radioiodinated aurones displayed high brain uptake (1.9-4.6% ID/g at 2 min) and rapid clearance from the brain (0.11-0.26% ID/g at 60 min), which is highly desirable for amyloid imaging agents. The results in this study suggest that novel radiolabeled aurones may be useful amyloid imaging agents for detecting ƒÀ-amyloid plaques in the brain of AD.