13C NMR detection of metabolic mixtures enhanced by Dynamic Nuclear Polarization

Dynamic Nuclear Polarization (DNP) shows a high potential to boost the sensitivity of NMR experiments. Particularly promising is the dissolution DNP approach, which can increase the sensitivity of certain liquid-state NMR experiments by factors in excess of 104. Usual applications of this promising technique rely on polarizing a 13C-labeled tracer, and following the latters metabolic fate after injection into an MRI scanner. This paper explores a different aspect pertaining the use of hyperpolarized metabolites, with a preliminary report exploring the potential of dissolution DNP in metabolomics analyses. To this end synthetic samples involving several common metabolites were hyperpolarized, and the analytical performance of the ensuing DNP NMR experiment was evaluated under a variety of different experimental conditions. These analyses revealed average signal enhancements of ~5000x to 10000x for non-protonated 13C sites, with a repeatability better than 10% on the 13C NMR peak areas. These are promising results, opening interesting application perspectives in the field of metabolomics analyses of biological extracts.