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Updated: May 7, 2026
09:37
Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR
Published on: February 12, 2019
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Fluorinated Biradicals for 19F Magic-Angle Spinning Dynamic Nuclear Polarization-Enhanced NMR Spectroscopy.
Judith Schlagnitweit1, Annabelle Peyronnet1, Gilles Casano2
1ENS Lyon, CNRS, Univ Claude Bernard Lyon 1, CRMN (Centre de RMN Très Hauts Champs de Lyon UMR 5082), 5 rue de la Doua, 69100 Villeurbanne, France.
Journal of the American Chemical Society
|May 6, 2026
Summary
New fluorinated radicals significantly boost 19F Dynamic Nuclear Polarization (DNP) NMR sensitivity and speed. This advance enables better detection of active pharmaceutical ingredients (APIs) in complex drug formulations and biological samples.
Area of Science:
- Nuclear Magnetic Resonance Spectroscopy
- Solid-State NMR
- Pharmaceutical Analysis
Background:
- Dynamic Nuclear Polarization (DNP)-enhanced solid-state NMR is crucial for studying low-concentration systems like APIs.
- 19F NMR offers selective detection of fluorine in APIs, but its DNP application is limited by hardware and polarizing agents.
Purpose of the Study:
- To develop and evaluate novel fluorinated biradicals for enhanced direct 19F DNP performance.
- To overcome limitations in current 19F DNP techniques for pharmaceutical analysis.
Main Methods:
- Synthesis of fluorinated analogs of TEKPol and bCTbK biradicals.
- Testing of these radicals using two model fluorinated drugs in various formulations.
- Comparison of 19F DNP performance against protonated counterparts.
Main Results:
- Fluorinated biradicals achieved superior signal enhancements (up to 330-fold in solution, 53-fold in a tablet).
- Significantly reduced polarization build-up times were observed with fluorinated radicals.
- Robust detection of APIs in challenging matrices was enabled.
Conclusions:
- Fluorinated radicals substantially improve sensitivity and acquisition speed in 19F DNP NMR.
- This advancement facilitates broader application of 19F DNP in pharmaceutical analysis.
- Enables API detection in settings where indirect polarization transfer is not feasible.
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