3-Carboxy-2,2,5,5-tetra(2H3)methyl-[4-2H(1H)]-3-pyrroline-(1-15N)-1-oxyl as a spin probe for in vivo L-band electron paramagnetic resonance imaging

The suitability of 3-carboxy-2,2,5,5-tetra(²H₃)methyl-[4-²H(¹H)]-3-pyrroline-(1-¹⁵N)-1-oxyl and its non-deuterated ¹⁴N-containing nitroxide analogue for L-band EPR in vivo imaging has been demonstrated. Both nitroxides exhibit low rates of reduction with ascorbate and slow decay in mice blood and plasma and, according to the EPR data, accumulate in the liver of a living mice within 10–70min after the injection via tail vein, and then collect in the bladder.