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Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
Dissolution DNP-NMR spectroscopy using galvinoxyl as a polarizing agent.
Lloyd L Lumata1, Matthew E Merritt, Craig R Malloy
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, 75390, United States.
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|December 19, 2012
Summary
Galvinoxyl is a feasible polarizing agent for dissolution dynamic nuclear polarization (DNP) NMR spectroscopy, achieving significant (13)C and (15)N nuclear polarization enhancements. Its solubility and ease of removal make it suitable for routine DNP-NMR applications.
Area of Science:
- Chemistry
- Spectroscopy
- Materials Science
Background:
- Dynamic Nuclear Polarization (DNP) NMR spectroscopy enhances sensitivity for low-gamma nuclei.
- Identifying effective and accessible polarizing agents is crucial for routine DNP-NMR applications.
Purpose of the Study:
- To evaluate galvinoxyl as a polarizing agent for dissolution DNP-NMR spectroscopy.
- To determine the optimal conditions for galvinoxyl-based DNP-NMR.
Main Methods:
- Solubility tests in various organic solvents.
- W-band Electron Spin Resonance (ESR) measurements to characterize the radical.
- Dissolution DNP-NMR experiments at 3.35 T and 1.4 K to measure nuclear polarization.
Main Results:
- Galvinoxyl demonstrated good solubility and glass-forming properties.
- ESR linewidth indicated predominant thermal mixing for low-gamma nuclei.
- Optimal concentration of 40 mM yielded ~6% (13)C polarization for ethyl acetate.
- Significant liquid-state NMR enhancements were observed for (13)C and (15)N compounds.
- Hydrophobic galvinoxyl was easily removed when using water as a solvent.
Conclusions:
- Galvinoxyl is a viable and easily accessible polarizing agent for routine dissolution DNP-NMR spectroscopy.
- Its properties facilitate efficient polarization and straightforward post-experiment processing.
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