Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89

PLoS One. 2017 Jun 2;12(6):e0178767. doi: 10.1371/journal.pone.0178767. eCollection 2017.

Abstract

The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. Herein we report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. While both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. Differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimization is necessary to enhance 89Zr chelation.

MeSH terms

  • Amides / chemistry*
  • Carbon-13 Magnetic Resonance Spectroscopy
  • Chelating Agents / chemistry*
  • Macrocyclic Compounds / chemistry*
  • Phthalic Acids / chemistry*
  • Proton Magnetic Resonance Spectroscopy
  • Spectrometry, Mass, Electrospray Ionization
  • Zirconium / chemistry*

Substances

  • Amides
  • Chelating Agents
  • Macrocyclic Compounds
  • Phthalic Acids
  • phthalic acid
  • Zirconium