Journal article
Structural characterization of lignin: a potential source of antioxidants guaiacol and 4-vinylguaiacol
International journal of biological macromolecules, Vol.75, pp.58-66
04/2015
Handle:
https://hdl.handle.net/2376/117129
PMID: 25603142
Abstract
The structure of lignin obtained from the ozone and soaking aqueous ammonia pretreatment of wheat straw has been characterized utilizing chemical analytical methods in order to reveal its antioxidant characteristics, including attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), pyrolysis/tetramethylammonium hydroxide-gas chromatography/mass spectrometry (Py/TMAH-GC/MS), gel permeation chromatography (GPC), ultra violet-visible spectroscopy (UV-vis), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) antioxidant evaluation assay. The results demonstrated that the isolated lignin is a ρ-hydroxyphenyl- guaiacyl-syringyl (H-G-S) lignin, with S/G ratio of 0.35 and significant amounts of phenol 2-methoxy (guaiacol) and phenol 2-methoxy-4-vinyl (4-vinylguaiacol). The Py-GC/MS and Py/TMAH-GC/MS pyrograms indicated that the major units in this lignin are derived from hydroxycinnamic acids. The GPC results revealed the molecular weight of the lignin was considerably low and also the FTIR analysis showed that the lignin possessed hydroxyl and methoxy functional groups; the factors led to the extracted lignin having a comparable antioxidant activity to that of currently used commercial antioxidants. The UV-vis and DPPH antioxidant assay results suggested a percentage of inhibition of the DPPH radicals in the following order: guaiacol (103.6 ± 1.36)>butylated hydroxytoluene (103.3 ± 1)>ferulic acid (102.6 ± 0.79)>pretreated lignin (86.9 ± 0.34).
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Details
- Title
- Structural characterization of lignin: a potential source of antioxidants guaiacol and 4-vinylguaiacol
- Creators
- Mohammadali Azadfar - Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA. Electronic address: mohammadali.azadfar@wsu.eduAllan Haiming Gao - Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USAMahesh V Bule - Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USAShulin Chen - Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA. Electronic address: chens@wsu.edu
- Publication Details
- International journal of biological macromolecules, Vol.75, pp.58-66
- Identifiers
- 99900582325301842
- Language
- English
- Resource Type
- Journal article