Amyloid Beta-Binding Bifunctional Chelators With Favorable Lipophilicity For Cu-64 Positron Emission Tomography Imaging In Alzheimer'S Disease

Herein, we report a new series of bifunctional chelators (BFCs) with a high affinity for amyloid aggregates, a strong binding affinity toward Cu(II), and favorable lipophilicity for potential blood-brain barrier penetration. The alkyl carboxylate ester pendant arms offer up to 3 orders of magnitude higher binding affinity toward Cu(II) and enable the BFCs to form stable Cu-64-radiolabeled complexes. Among the five compounds tested, the Cu-64-YW-7 and Cu-64-YW-10 complexes exhibit strong and specific staining of amyloid plaques in ex vivo autoradiography studies. Importantly, these BFCs have promising partition coefficient (log D-oct) values of 0.91-1.26 and show some brain uptake in biodistribution studies using CD-1 mice. Overall, these BFCs could serve as lead compounds for the development of positron emission tomography imaging agents for AD diagnosis.