99mTc/Re complexes based on flavone and aurone as SPECT probes for imaging cerebral β-amyloid plaques

Two (99m)Tc/Re complexes based on flavone and aurone were tested as potential probes for imaging β-amyloid plaques using single photon emission computed tomography. Both (99m)Tc-labeled derivatives showed higher affinity for Aβ(1-42) aggregates than did (99m)Tc-BAT. In sections of brain tissue from an animal model of AD, the Re-flavone derivative 9 and Re-aurone derivative 19 intensely stained β-amyloid plaques. In biodistribution experiments using normal mice, (99m)Tc-labeled flavone and aurone displayed similar radioactivity pharmacokinetics. With additional modifications to improve their brain uptake, (99m)Tc complexes based on the flavone or aurone scaffold may serve as probes for imaging cerebral β-amyloid plaques.