Bispidines for Dual Imaging. Issue 51 (24th October 2014)

• Record Type: Journal Article
• Authors: Stephan, Holger; Walther, Martin; Fähnemann, Silke; Ceroni, Paola; Molloy, Jennifer K.; Bergamini, Giacomo; Heisig, Fabian; Müller, Christa E.; Kraus, Werner; Comba, Peter
• Is Part Of: Chemistry. Volume 20:Issue 51(2014)
• Page Start: 17011
• Page End: 17018
• Publication Date: 2014-10-24
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201404086
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The efficient transformation of the hexadentate bispidinol <bold>1</bold> into carbamate derivatives yields functional bispidines enabling convenient functionalization for targeted imaging. The BODIPY‐substituted bispidine <bold>3</bold> combines a coordination site for metal ions, such as radioactive <sup>64</sup>Cu<sup>II</sup>, with a fluorescent unit. Product <bold>3</bold> was thoroughly characterized by standard analytical methods, single crystal X‐ray diffraction, radiolabeling, and photophysical analysis. The luminescence of ligand <bold>3</bold> was found to be strongly dependent on metal ion coordination: Cu<sup>II</sup> quenches the BODIPY fluorescence, whereas Ni<sup>II</sup> and Zn<sup>II</sup> ions do not affect it. It follows that, in imaging applications with the positron emitter <sup>64</sup>Cu<sup>II</sup>, residues of its origin from enriched <sup>64</sup>Ni and the decay products <sup>64</sup>Ni<sup>II</sup> and <sup>64</sup>Zn<sup>II</sup>, efficiently restore the fluorescence of the ligand. This allows for monitoring of the emitted radiation as well as the fluorescence signal. The stability of the <sup>64</sup>Cu<sup>II</sup><bold>3</bold> complex is investigated by transmetalation experiments with Zn<sup>II</sup> and Ni<sup>II</sup>, using fluorescence and radioactivity detection, and the results confirm the high stability of <sup>64</sup>Cu<sup>II</sup><bold>3</bold>. In addition, metal complexes of ligand <bold>3</bold> with the lanthanide ions Tb<sup>III</sup>, Eu<sup>III</sup>, and Nd<sup>III</sup> are shown to exhibit emission of the BODIPY ligand and the lanthanide ion, thus enabling dual emission detection.</p> </abstract>