Invited Speaker 23rd International Society of Magnetic Resonance Conference 2023

Hyperpolarized 13C NMR metabolomics at natural abundance (#91)

Patrick Giraudeau 1
  1. Nantes Université, Nantes Cedex 3, PAYS DE LA LOIRE, France

Nuclear Magnetic Resonance (NMR) spectroscopy is a major analytical tool for metabolomics, and has shown great promises in many areas of science in complementarity with mass spectrometry.1,2 Most NMR metabolomics studies rely on 1D 1H spectroscopy, which provides an acceptable sensitivity, but strongly suffers from ubiquitous overlap between complex metabolite patterns. In contrast, 13C NMR spectroscopy has many advantageous features such as narrow singlets and a broad spectral range. It would be ideal for metabolomics, were it not for the fact that its low sensitivity is not compatible with the detection of low-concentrated analytes at natural abundance.

Dissolution Dynamic Nuclear Polarization (d-DNP) provides a unique and general way to detect 13C NMR signals with a sensitivity enhanced by several orders of magnitude.3 We showed that thanks to the excellent repeatability of a prototype d-DNP equipment, 13C NMR at natural abundance can be applied to plant extracts and incorporated in a full untargeted metabolomics workflow, providing efficient sample group separation and biomarker identification after statistical analysis.4 However, the initial experimental setting remained limited to relatively concentrated samples. Therefore, we systematically optimized the parameters involved in our d-DNP setting, leading to major sensitivity and resolution improvements.5 Thanks to this optimization, we recently reported the first d‑DNP-enhanced 13C NMR analysis of a biofluid -urine- at natural abundance, offering unprecedented resolution and sensitivity for this challenging type of sample.6 We also showed that accurate quantitative information on multiple targeted metabolites could be retrieved through a standard addition procedure.

These results open many perspectives for 13C NMR-based metabolomics at natural abundance, but also raise a number of analytical challenges in terms of metabolite identification, cost and throughput. We will discuss the potential of this new approach, as well as undergoing methodological developments to further improve its performance, such as the acquisition of hyperpolarized ultrafast 2D heteronuclear spectra or the simultaneous acquisition of 1H and 13C spectra with parallel receivers following a single d-DNP experiment.

  1. Letertre, M. P. M., Dervilly, G., Giraudeau, P., Anal. Chem., 2021, 93, 500-518.
  2. Letertre, M. P. M., Giraudeau, P., de Tullio, P., Front. Mol. Biosci., 2021, 8.
  3. Ardenkjaer-Larsen, J. H., Fridlund, B., Gram, A., Hansson, G., Hansson, L., Lerche, M. H., Servin, R., Thaning, M., Golman, K., Proc. Natl. Acad. Sci. U. S. A., 2003, 100, 10158-10163.
  4. Dey, A., Charrier, B., Martineau, E., Deborde, C., Gandriau, E., Moing, A., Jacob, D., Eshchenko, D., Schnell, M., Melzi, R., Kurzbach, D., Ceillier, M., Chappuis, Q., Cousin, S. F., Kempf, J. G., Jannin, S., Dumez, J.-N., Giraudeau, P., Anal. Chem., 2020, 92, 14867-14871.
  5. Dey, A., Charrier, B., Lemaitre, K., Ribay, V., Eshchenko, D., Schnell, M., Melzi, R., Stern, Q., Cousin, S. F., Kempf, J. G., Jannin, S., Dumez, J. N., Giraudeau, P., Magn. Reson., 2022, 3, 183-202.
  6. Ribay, V., Dey, A., Charrier, B., Praud, C., Mandral, J., Dumez, J.-N., Letertre, M. P. M., Giraudeau, P., Angew. Chem. Int. Ed., 2023, in press.