¹⁹F PARASHIFT Probes for Magnetic Resonance Detection of H₂O₂ and Peroxidase Activity

Elevated levels of reactive oxygen species and peroxidase expression are often associated with inflammation and inflammatory diseases. We developed two novel Co­(II) complexes that can be used to detect oxidative activity associated with inflammation using 19F magnetic resonance imaging (MRI). These agents display a large change in 19F chemical shift upon oxidation from Co­(II) to Co­(III), facilitating selective visualization of both species using chemical shift selective pulse sequences. This large chemical shift change is attributed to a large magnetic anisotropy in the high spin Co­(II) complexes. Importantly, the differing reactivity of the two agents allows for detection of either H2O2 production and/or the activity of peroxidase enzymes, providing two useful platforms for 19F MR hot spot imaging of oxidative events associated with biological inflammation.