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Updated: Jun 14, 2025
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Quantitative 31P NMR Analysis of Lignins and Tannins
Published on: August 2, 2021
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Lignin Structural Characterization and Its Antioxidant Potential: A Comparative Evaluation by EPR, UV-Vis
Tina Ročnik Kozmelj1, Maxim A Voinov2, Miha Grilc1
1Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1001 Ljubljana, Slovenia.
International Journal of Molecular Sciences
|August 29, 2024
Summary
Lignin and its fragments exhibit significant antioxidant and free radical scavenging properties. This study confirms their potential for industrial applications using advanced spectroscopic methods.
Area of Science:
- Polymer Chemistry
- Biomaterials Science
- Analytical Chemistry
Background:
- Lignin, a natural aromatic polymer, is recognized for its antioxidant properties.
- Lignin-derived oligomers also show potential as antioxidants.
- Understanding their radical scavenging activity is crucial for application development.
Purpose of the Study:
- To evaluate the antioxidant capacity and free radical scavenging activity of fractionated organosolv lignin and its oligomeric fragments.
- To compare results obtained from electron paramagnetic resonance (EPR) and UV-Vis spectroscopy.
- To provide reliable data on lignin's antioxidant potential for industrial use.
Main Methods:
- Utilized a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.
- Employed electron paramagnetic resonance (EPR) spectroscopy to measure free radical quenching.
- Applied UV-Vis spectroscopy to determine radical scavenging activity (RSA).
- Analyzed EPR data to derive kinetic rate constants.
Main Results:
- Both lignin and its oligomeric fragments demonstrated significant antioxidant activity.
- EPR measurements confirmed efficient free radical quenching by lignin.
- UV-Vis spectroscopy provided comparable RSA values, validating the EPR findings.
- Kinetic rate constants for radical scavenging were successfully derived.
Conclusions:
- Fractionated organosolv lignin and its oligomers possess notable antioxidant and radical scavenging capabilities.
- The combined EPR and UV-Vis spectroscopic approach enhances the reliability of antioxidant assessment.
- Lignin derivatives show promise for applications in pharmaceuticals, food preservation, and cosmetics.
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