New cross-bridged cyclam derivative CB-TE1K1P, an improved bifunctional chelator for copper radionuclides

Abstract

A new cross-bridged cyclam chelator, CB-TE1K1P, was developed for copper-based radiopharmaceuticals, and this chelator can be labelled with ⁶⁴Cu under mild conditions in high specific activity. DBCO–PEG₄–CB-TE1K1P was synthesized for conjugation to proteins, while Dde–CB-TE1K1P(^tBu₂)–OH was synthesized for solid-phase peptide synthesis. Examples of the conjugation chemistry, radiolabelling and serum stability of each are presented.