Synthesis and biological evaluation of gallium polyaminothiols (PAT)

Nucl Med Biol. 1993 Feb;20(2):217-23. doi: 10.1016/0969-8051(93)90118-e.

Abstract

Two polyaminothiol ligands, one hexadentate, N,N',N"-tris[2-methyl(2-propanethiol)]-1,4,7-triazacyclononane (TACN), and another potentially heptadentate, tris[2-methyl(2-propanethiol)]aminoethylamine (TMAE), were synthesized and characterized using spectroscopic and analytical methods. Both ligands were labeled with gallium-67 at pH 3.0-3.5 in high yields. The resulting gallium chelates were lipophilic. The biodistribution studies for both the chelates showed hepatic uptake and biliary clearance. The total % ID activity for [67Ga]TACN in liver and intestine at 5 min was 33.86 increasing gradually to 61.4% at 30 min. The chelates were in vivo stable to plasma-transferrin transchelation as confirmed by scintigraphic images obtained by [67Ga]TACN in rats and by plasma incubation of the chelates. These results indicate that Ga-TACN is a potentially useful tracer for hepatobiliary imaging using PET. No brain uptake was found.

MeSH terms

  • Animals
  • Ethylenediamines / chemical synthesis*
  • Ethylenediamines / pharmacokinetics
  • Gallium Radioisotopes / pharmacokinetics*
  • Heterocyclic Compounds / chemical synthesis*
  • Heterocyclic Compounds / pharmacokinetics
  • Humans
  • Injections, Intravenous
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Radionuclide Imaging
  • Rats
  • Rats, Sprague-Dawley
  • Sulfhydryl Compounds / chemical synthesis*
  • Sulfhydryl Compounds / pharmacokinetics
  • Tissue Distribution

Substances

  • Ethylenediamines
  • Gallium Radioisotopes
  • Heterocyclic Compounds
  • Sulfhydryl Compounds
  • N,N',N''-tris(2-methyl-(2-propanethiol))-1,4,7-triazacyclononane
  • tris(2-methyl-(2-propanethiol))aminoethylamine