Long-lived coherences for the observation of oxidation kinetics on different timescales by NMR.

For non-invasive imaging of biochemical processes, the ability of NMR to follow biomolecular transformations on different time windows needs to be improved. Long-lived coherences (LLC's) are molecular-symmetry-adapted nuclear spin coherences that can be sustained for durations up to an order of magnitude longer compared to classical coherences in high-field magnets. 2D-LLC experiments provide contrast for targeted molecules against cell background, as demonstrated herein for glutathione (GSH), a major antioxidant in immune cells and rapidly-proliferating tumors. We tested the oxidative response of immune B-cells to exogenous incubated glutathione and high-dose-rate laser-driven radiation. We found agreement between biochemical methods and 2D-LLC for detecting GSH production induced by incubation. To also address oxidation on FLASH radiation response-relevant timescales, we demonstrate a direct 1D method, WINDOW-LLC. Using this method, we recorded multiple points of GSH oxidation kinetics within 15 seconds after a single excitation step. Thus, LLC's find potential applications to detect oxido-reduction processes.