Synthesis of (13) C2 (15) N2 -labeled anti-inflammatory and cytoprotective tricyclic bis(cyanoenone) ([(13) C2 (15) N2 ]-TBE-31) as an internal standard for quantification by stable isotope dilution LC-MS method

J Labelled Comp Radiopharm. 2014 Aug;57(10):606-10. doi: 10.1002/jlcr.3230. Epub 2014 Sep 5.


Tricyclic bis(cyanoenone), TBE-31, one of the most potent activators of the Keap1/Nrf2/antioxidant response element pathway, has been developed as a new anti-inflammatory and cytoprotective agent. (13) C2 (15) N2 -labeled TBE-31 ([(13) C2 (15) N2 ]-TBE-31), which has two (13) C and two (15) N atoms in two cyano groups, was designed to develop a method for quantification of cell, tissue, and plasma levels of TBE-31 that involves chromatography/mass spectrometry coupled with the use of a stable isotope-labeled internal standard. [(13) C2 (15) N2 ]-TBE-31 was successfully synthesized in four steps from a previously reported intermediate, which is prepared in 11 steps from cyclohexanone, by introduction of two (13) C atoms with ethyl [(13) C]formate and two (15) N atoms with hydroxyl[(15) N]amine. The stable isotope dilution liquid chromatography-mass spectrometry method for quantification of TBE-31 was successfully developed using [(13) C2 (15) N2 ]-TBE-31 to compensate for any variables encountered during sample processing and analysis.

Keywords: Keap1/Nrf2/ARE activator; anti-inflammatory; carbon-13; cytoprotective; isotopically labeled synthesis; nitrogen-15; stable isotope dilution LC-MS method.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / chemical synthesis*
  • Anti-Inflammatory Agents / pharmacokinetics
  • Carbon Isotopes / chemistry
  • Carbon Isotopes / pharmacokinetics
  • Cell Line, Tumor
  • Chromatography, Liquid / standards
  • Mass Spectrometry / standards
  • Mice
  • Nitrogen Radioisotopes / chemistry
  • Nitrogen Radioisotopes / pharmacokinetics
  • Phenanthrenes / chemical synthesis*
  • Phenanthrenes / pharmacokinetics
  • Radioisotope Dilution Technique / standards
  • Radiopharmaceuticals / chemical synthesis*
  • Radiopharmaceuticals / pharmacokinetics
  • Reference Standards


  • Anti-Inflammatory Agents
  • Carbon Isotopes
  • Nitrogen Radioisotopes
  • Phenanthrenes
  • Radiopharmaceuticals
  • TBE 31