A robust approach to generate high polarization levels of metabolites within seconds with para-hydrogen

Synopsis

Hyperpolarization of metabolites is a promising approach for in vivo disease detection and observation of treatment responses.^1-4 Among hyperpolarization techniques, para-hydrogen induced polarization (PHIP) represents an inexpensive approach to generate polarization within a few seconds.^5-11 Here, we are introducing a pulsed magnetic resonance method to polarize metabolites that enables us to efficiently transfer proton polarization to a ¹³C nucleus of interest. This becomes especially possible by attaching an optimized molecular sidearm to a metabolite of choice (here: acetate, glycine and pyruvate) which is para-hydrogenated and the polarization subsequently transferred. We have achieved high levels of metabolite precursor polarization (P >10%) with para-hydrogen within 15 seconds. Cleavage of the sidearm yields hyperpolarized metabolites.