Synthesis and characterization of natural lanthanum labelled DOTA-Peptides for simulating radioactive Ac-225 labeling

Highlights: • DOTATATE and PSMA-617 chelator peptides were labelled with using La metal for simulating ²²⁵Ac. • The materials were characterized by UV-VIS, fluorescence spectroscopy, and LC-ESI-MS techniques. • The purification procedure was optimized by using two different column. - Abstract: This research aimed to assess the labeling procedure of Lanthanum to DOTATATE and PSMA-617 peptide for simulating Actinium-225 (²²⁵Ac) labeling. For this purpose labeling procedure, purification and characterization conditions were optimized. Results showed that for the high reaction yield labeling, microwave heating should be preferred and Sephadex G10 column was found to be more suitable as a purification system compared to Toyopearl column. For the characterization of complex, more precise and reliable results were obtained by the chromatographic system.