Biological J‐Coupling Spectroscopy at Low Magnetic Field

Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for investigating biological systems. In particular, low‐field NMR offers advantages for studying cellular metabolism in their native environment. This is especially relevant for in vitro studies, where low‐field NMR can be used to analyze biological samples with reduced equipment size and cost, potentially enabling high‐throughput benchtop research. However, the study of cellular metabolism at low, milli‐Tesla, magnetic fields remains an unsolved challenge due to reduced chemical shifts and dominant spin‐spin couplings ( J ‐couplings) that complicate spectral analysis. Herein, this problem is tackled by combining J ‐coupling spectroscopy and parahydrogen‐induced polarization with a multinuclear scanner built in‐house. The results demonstrate the ability to resolve pyruvate metabolism of cancer cells in regular NMR tubes at milli‐Tesla fields using [2‐ 13 C]pyruvate. This work concludes that low‐field biological J ‐coupling spectroscopy can be a valuable tool for studying cellular metabolism, enabling new insights into biological systems.