Di-macrocyclic terephthalamide ligands as chelators for the PET radionuclide zirconium-89

The development of bifunctional chelators (BFCs) which can stably chelate zirconium-89 (Zr-89) while being conjugated to targeting molecules is an area of active research. Herein we report the first octadentate terephthalamide ligands, which are easily radiolabeled with Zr-89 and are highly stable in vitro. They represent a novel class of chelators, which are worthy of further development as BFCs for Zr-89.