Synthetic approaches to modified calixarene ligands for imaging applications

Radionuclides are finding increased use in medical imaging. Two such nuclides are In-111 and Ga-68. If these isotopes are to have applications in brain perfusion imaging, ligands need to be available which will form lipophilic neutral complexes with these metal ions. The authors strategy is to use synthetically modified calix-4-arenes as encapsulating ligands for these trivalent ions. Synthetic approaches to synthesizing such ligands are discussed, along with initial studies on their complexation