Synthesis, characterization and evaluation of a Cu-labeled macrocyclic-porphyrin as a potential chelator for 64Cu-based radiopharmaceuticals

• Published in: Journal of radioanalytical and nuclear chemistry 2019-04, Vol.320 (1), p.79-86
• Main Authors: Aguilar-Ortiz, Edgar, Jalilian, Amir R., Avila-Rodriguez, Miguel A.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Coordination compounds; Cyclotrons; Diagnostic Radiology; Hadrons; Heavy Ions; Image acquisition; Inorganic Chemistry; NMR; Nuclear Chemistry; Nuclear magnetic resonance; Nuclear Physics; Physical Chemistry; Radiolabelling; Receptors; Synthesis
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-019-06454-4

Synthesis of 5-(4-aminophenyl)-10,15,20-triphenyl porphyrin ( B ) was performed using the Lindsey method and characterized by 1 H NMR. Cu-porphyrin complexation conditions were tested using nat Cu and UV–Vis analysis confirmed metallation. High specific activity 64 Cu was produced via cyclotron using the 64 Ni(p,n) reaction. For radiolabeling, 64 CuCl 2 dissolved in acetate buffer (pH 5.6) was mixed with compound ( B ) in DMSO, and incubated for 60 min at 37 °C, obtaining a labeling yield > 95% at 60 min. The labeled complex [ 64 Cu]-5-(4-aminophenyl)-10,15,20-triphenyl porphyrin ( C ) showed good stability (> 95%) for up 48 h when incubated in human serum. MicroPET images were acquired in rats and mice using 64 Cu-porphyrin ( C ) and 64 CuCl 2 in order to compare their biodistribution. Results suggest that ( C ) is an excellent candidate to prepare stable metal complexes suitable for the development of novel 64 Cu-based radiopharmaceuticals using biological moieties to target specific receptors.