Two bifunctional desferrioxamine chelators for bioorthogonal labeling of biovectors with zirconium-89.

We report two bifunctional chelators, DFO-Cys and DFO-CBT, to label biovectors with zirconium-89 according to the 2-cyanobenzothiazole/1,2-aminothiol cycloaddition. Their features are high labeling yields, rapid and efficient bioconjugation, metabolically stable luciferin-based end products, and applicability to orthogonal two-step labeling of sensitive biomolecules.