18F-labeled flavones for in vivo imaging of ƒÀ-amyloid plaques in Alzheimer's
brains.
ABSTRACT
In vivo imaging of ƒÀ-amyloid (AƒÀ) aggregates in the brain may lead to early
detection of Alzheimer's disease (AD) and monitoring of the progression
and effectiveness of treatment. The purpose of this study was to develop
novel 18F-labeled amyloid-imaging probes based on flavones as a core structure.
Fluoropegylated (FPEG) flavone derivatives were designed and synthesized.
The affinity of the derivatives for AƒÀ aggregates varied from 5 to 321nM.
In brain sections of AD model mice, FPEG flavones with the dimethylamino
group intensely stained ƒÀ-amyloid plaques. In biodistrubution experiments
using normal mice, they displayed high uptake in the brain ranging from
2.9 to 4.2%ID/g at 2 min postinjection. The radioactivity washed out from
the brain rapidly (1.3-2.0%ID/g at 30 min), which is highly desirable for
ƒÀ-amyloid imaging agents. FPEG flavones may be potential PET imaging agents
for ƒÀ-amyloid plaques in Alzheimer's brains.