Novel Spin Adduct for Free Radical Elimination

5-carbamoyl-5-methyl-1-pyrroline N-oxide (AMPO) as an improved cyclic spin trap, especially in mitigating superoxide radicals.

The Need

The linear PBN-type nitrones are limited by their ability to discern different radicals while the cyclic DMPO-type nitrones are limited by the stability of the adducts they form. Enolized DMPO-type spin adducts have been shown to dimerize and produce a six-line electron paramagnetic resonance (EPR) spectrum independently1. Ideal spin traps should minimize EPR absorption in the absence of ROS sources.

  1. Hideg | 16:Direct Detection of Free Radicals and Reactive Oxygen Species in Thylakoids | 2011

The Technology

The Ohio State University researchers, led by Dr. Jay Zweier, have shown that AMPO and its spin adduct AMPO-OH have similar or potentially better electronic and thermodynamic properties than phosphorylated or carboxylated nitrones and their adducts. AMPO is a solid spin trap that is easy to purify without generating paramagnetic impurities which occurs in many commercially available spin traps. Also, the rate of superoxide trapping in AMPO is faster than DEPMPO, EMPO and DMPO.

Commercial Applications

  • Antioxidant industry
  • Chemical research
  • Biological research
  • Paramagnetic resonance spectroscopy


  • Easy to purify without giving paramagnetic impurities
  • Half-life of about 8-9 minutes and suitable as a probe for superoxide radical

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