Synthesis of heptadentate (N4O3) amine-phenol ligands and radiochemical studies with technetium-99m

Heptadentate amine-phenol ligands with N4O3 donor atoms for coordination we re synthesized by condensing tris(2-aminoethyl)amine with salicylaldehyde o r acetophenone and reducing the Schiff bases formed with NaBH4. The ligands were characterized by H-1 and C-13 nuclear magnetic resonance spectroscopy . Radiochemical studies were carried out with no-carrier-added Tc-99m and T c-99m spiked with 0.1-100 mu M of Tc-99. Complexation yields were estimated from thin layer chromatography, paper electrophoresis, and solvent extract ion studies. Tc-99m complexes were formed in yields better than 90% with th e amine-phenol ligands. The complexes were found to be neutral and lipophil ic. Biodistribution studies of the Tc-99m complexes showed that clearance w as mainly through the hepatobiliary system. NUCL MED BIOL 26;2: 233-238, 19 99. (C) 1999 Elsevier Science Inc. All rights reserved.