A novel series of aurone derivatives for in vivo imaging of beta-amyloid plaques in the brain of Alzheimer's disease (AD) were synthesized and characterized. When in vitro binding studies using A beta(1-42) aggregates were carried out with aurone derivatives, they showed high binding affinities for A beta(1-42) aggregates at the K-i 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 beta-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 P-amyloid plaques in the brain of AD. (c) 2007 Elsevier Inc. All rights reserved.