Synthesis of [(125)I]iodoDPA-713: a new probe for imaging inflammation

Biochem Biophys Res Commun. 2009 Nov 6;389(1):80-3. doi: 10.1016/j.bbrc.2009.08.102. Epub 2009 Aug 22.

Abstract

[(125)I]IodoDPA-713 [(125)I]1, which targets the translocator protein (TSPO, 18 kDa), was synthesized in seven steps from methyl-4-methoxybenzoate as a tool for quantification of inflammation in preclinical models. Preliminary in vitro autoradiography and in vivo small animal imaging were performed using [(125)I]1 in a neurotoxicant-treated rat and in a murine model of lung inflammation, respectively. The radiochemical yield of [(125)I]1 was 44+/-6% with a specific radioactivity of 51.8 GBq/micromol (1400 mCi/micromol) and >99% radiochemical purity. Preliminary studies showed that [(125)I]1 demonstrated increased specific binding to TSPO in a neurotoxicant-treated rat and increased radiopharmaceutical uptake in the lungs of an experimental inflammation model of lung inflammation. Compound [(125)I]1 is a new, convenient probe for preclinical studies of TSPO activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides / chemical synthesis
  • Acetamides / chemistry*
  • Acetamides / pharmacokinetics
  • Animals
  • Brain / diagnostic imaging
  • Female
  • Inflammation / diagnostic imaging*
  • Mice
  • Mice, Inbred Strains
  • Molecular Probes / chemical synthesis
  • Molecular Probes / chemistry*
  • Molecular Probes / pharmacokinetics
  • Pneumonia / diagnostic imaging
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry*
  • Pyrazoles / pharmacokinetics
  • Pyrimidines / chemical synthesis
  • Pyrimidines / chemistry*
  • Pyrimidines / pharmacokinetics
  • Radiopharmaceuticals / chemical synthesis
  • Radiopharmaceuticals / chemistry*
  • Radiopharmaceuticals / pharmacokinetics
  • Rats
  • Receptors, GABA / analysis*
  • Receptors, GABA / metabolism
  • Tomography, Emission-Computed

Substances

  • Acetamides
  • Molecular Probes
  • N,N-diethyl-2-(2-(4-methoxyphenyl)-5,7-dimethyl-pyrazolo(1,5-a)pyrimidin-3-yl)-acetamide
  • Pyrazoles
  • Pyrimidines
  • Radiopharmaceuticals
  • Receptors, GABA
  • TSPO protein, human
  • N,N-diethyl-2-(2-(3-iodo-4-methoxyphenyl)-5,7-dimethylpyrazolo(1,5-a)pyrimidin-3-yl)acetamide