Preparation and Biodistribution of Technetium-99m Labeled with N2O2 Imine-Phenol Ligand

Abstract

A series of tetradentate imine phenol compounds were synthesized by condensing 1 equiv. of 1,2-diamine derivatives along with four groups of 2 equiv. of salicylaldehyde derivatives. Chemical characteristics of the prepared compounds were analyzed using instruments including proton nuclear magnetic resonance (1H-NMR) and elemental analysis (EA). The above imine phenol compounds were labeled with tracer-level 99mTcO4- to proceed with complex in forming 99mTc-complexes. Labeling yields of the 99mTc-complexes were higher in pH 8~9 than other pH ranges as evaluated using the solvent extraction technique. The complexes studied varied in lipophilicity from Log P = 1.51 to Log P = 2.21, where P was the octanol/water partition coefficient. The electric charges of all the 99mTc-complexes are neutrality. The biodistribution tests present that the metabolic pathway of the 99mTc-complexes on Wistar rats is via hepatobiliary duct. As the highest lipophilicities of 99mTc-(4-MeOsal)2bn and 99mTc-(4-MeOsal)2pt than those of the remaining 99mTc-complexes, the relative activities in hepatobiliary duct at 120 min postinjection also indicate the highest radioactivity as compared with other 99mTc-complexes.