Aurones serve as probes of β-amyloid plaques in Alzheimer’s disease

A novel series of aurone derivatives for in vivo imaging of β-amyloid plaques in the brain of Alzheimer’s disease (AD) were synthesized and characterized. When in vitro binding studies using Aβ(1−42) aggregates were carried out with aurone derivatives, they showed high binding affinities for Aβ(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 β-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 β-amyloid plaques in the brain of AD.