Detection of muconic acid type structures in oxidised lignins using 2D NMR spectroscopy 10<sup>th</sup> EWLP, Stockholm, Sweden, August 25–28, 2008

Evtuguin, Dmitry V.; Rocha, Graça M. S. R. O.; Goodfellow, Brian J.

doi:10.1515/hf.2009.083

Cited by 11 publications

(8 citation statements)

References 16 publications

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“…Compounds 5a (muconic acid derivative) and 5b (o-quinone derivative) were obtained by oxidation of 5 with chlorine dioxide according to the procedure described previously. [8] Birch (Betula pendula) xylan was isolated by the extraction of peracetic holocellulose with 5% KOH. HexA-enriched xylan was obtained by treatment of xylan in 1 M NaOH solution at 150 • C for 30 min.…”

Section: Methodsmentioning

confidence: 99%

“…5‐formyl‐2‐furancarboxylic acid (the only one supplied by TCI Europe). Compounds 5a (muconic acid derivative) and 5b ( o ‐quinone derivative) were obtained by oxidation of 5 with chlorine dioxide according to the procedure described previously 8. Birch ( Betula pendula ) xylan was isolated by the extraction of peracetic holocellulose with 5% KOH.…”

Section: Methodsmentioning

confidence: 99%

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UV‐resonance Raman micro‐spectroscopy to assess residual chromophores in cellulosic pulps

Loureiro

Fernandes

Furtado³

et al. 2010

J Raman Spectroscopy

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Ultraviolet-resonance Raman (UV-RR) micro-spectroscopy is an appropriate and sensitive tool to assess the chromophore structures in bleached cellulosic pulps used for papermaking. The particular selectivity in detection and identification of chromophores in pulps is achieved by acquiring the UV-RR spectra in the solid state with laser excitation at 325 nm. This wavelength corresponds to absorption of poly-unsaturated chromophore structures in partially bleached/fully bleached pulps, and linearly correlated with the signal at ca 1600 cm −1 in the UV-RR spectra. The characteristic vibrations from particular pulp chromophore structures have been assigned from experiments with model compounds, thus allowing the establishment of a UV-RR database. Among the components of bleached pulp, the xylan-lignin complex was suggested to be an important source of chromophores. The monitoring of pulp bleaching by UV-RR allowed us to suggest that it is the formation of new polysaccharide-derived chromophores upon bleaching that hinders development of further brightness and is co-responsible for the brightness reversion of fully bleached pulps.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

UV‐resonance Raman micro‐spectroscopy to assess residual chromophores in cellulosic pulps

Loureiro

Fernandes

Furtado³

et al. 2010

J Raman Spectroscopy

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“…According to [45,54], the absorption band νС=О of α,β-unsaturated carboxylic acids is ~1720 cm −1 . Then, for dimers cis,cis-muconic acid νC=O is 1680-1689 cm −1 [58,60]. Сis,cis-muconic acid can be produced via the oxidative 1,2-cleavage of catechol, a central intermediate in degradation of aromatic compounds in many aromatic-catabolizing microbes [61].…”

Section: Thermal Transformations Of Ca On the Nanoceria Surfacementioning

confidence: 99%

Thermal Transformation of Caffeic Acid on the Nanoceria Surface Studied by Temperature Programmed Desorption Mass-Spectrometry, Thermogravimetric Analysis and FT–IR Spectroscopy

Nastasiienko

Palianytsia

Кartel

et al. 2019

Colloids and Interfaces

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The studies of pyrolysis of caffeic acid (CA) and its surface complexes is important for the development of technologies of heterogeneous catalytic pyrolysis of plant- and wood- based renewable biomass components. In this work, the structure and thermal transformations of the surface complexes of CA on the surface of nanoceria were investigated using Fourier transform–infrared (FT–IR) spectroscopy, thermogravimetric analysis (TGA) and temperature-programmed desorption mass spectrometry (TPD MS). It was found that CA on the surface of cerium dioxide forms several types of complexes: bidentate carboxylates, monodentate carboxylates and complexes formed as a result of interaction with phenolic hydroxyl groups. This is due to the ability of nanosized cerium dioxide to generate basic hydroxyl groups that can deprotonate phenolic groups to form phenolates on the surface. The main pyrolysis products were identified. The possible ways of forming 3,4-dihydroxyphenylethylene, acetylene carboxylic acid, pyrocatechol and phenol from surface complexes of CA were suggested. It was established that on the nanoceria surface effectively occur the decarboxylation, decarbonylation, and dehydration reactions of the CA, which are the desirable processes in biomass conversion technologies.

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“…However, the recovery procedure used in these experiments fails to recover the whole amount of lignin removed in AWO delignification of PT/E MK PT. This might be attributed to the lignin conversion to compounds, which are not extractable by selected organic solvents (e.g., the formation of hydrophilic compounds, such as carboxyl acids resulting from the cleavage of aromatic ring [46]). A higher lignin content of E MK PTL 1 than of PTL 1 determined in these experiments (88.0% vs. 81.8%) demonstrates the beneficial effect of HWE on the purity of lignin recovered: the cleavage of lignin-carbohydrate bonds occurs to some extent during HWE [8,40,43].…”

Section: Lignin Isolation From the Spent Liquor Of Awo Delignificatiomentioning

confidence: 99%

“…The lignin isolated in these experiments has undergone an oxidative acidic treatment, leading to substantial changes of lignin structure. A decrease in the lignin absorption in UV area is expected as a result of these changes and might offer evidence for decrease in lignin aromaticity/aromatic cleavage during AWO [46,51]. Additionally, the main cross-signals from syringyl (S) and guaiacyl (G) lignin units can be observed in both PTL 1 and E MK PTL 1 in the aromatic region of the HSQC spectra.…”

Section: Lignin Characterization By 2d Hsqc Nmrmentioning

confidence: 99%

Impact of Hot-Water Extraction on Acetone-Water Oxygen Delignification of Paulownia Spp. and Lignin Recovery

Gong

Bujanovic

2014

Energies

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A hardwood-based biorefinery process starting with hot-water extraction (HWE) is recommended in order to remove most of the hemicelluloses/xylans before further processing. HWE may be followed by delignification in acetone/water in the presence of oxygen (AWO) for the production of cellulose and lignin. In this study, the HWE-AWO sequence was evaluated for its effectiveness at removing lignin from the fast-growing species Paulownia tomentosa (PT) and Paulownia elongata (PE), in comparison with the reference species, sugar maple (Acer saccharum, SM). HWE might lead to a remarkable increase in lignin accessibility, and as a result, a greater AWO delignification degree was observed for extracted PT, PE, and SM than for unextracted ones. Organosolv lignin was recovered from the spent liquor of AWO delignification of PT with/without prior HWE and characterized to evaluate the benefits of HWE on the lignin structure and purity. The lignin recovered from the spent liquor of HWE-AWO sequence is of higher purity and lighter color than that recovered from the AWO spent liquor. These properties along with low sulfur content are desirable for lignin high-value applications.

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Detection of muconic acid type structures in oxidised lignins using 2D NMR spectroscopy 10^th EWLP, Stockholm, Sweden, August 25–28, 2008

Cited by 11 publications

References 16 publications

UV‐resonance Raman micro‐spectroscopy to assess residual chromophores in cellulosic pulps

UV‐resonance Raman micro‐spectroscopy to assess residual chromophores in cellulosic pulps

Thermal Transformation of Caffeic Acid on the Nanoceria Surface Studied by Temperature Programmed Desorption Mass-Spectrometry, Thermogravimetric Analysis and FT–IR Spectroscopy

Impact of Hot-Water Extraction on Acetone-Water Oxygen Delignification of Paulownia Spp. and Lignin Recovery

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Detection of muconic acid type structures in oxidised lignins using 2D NMR spectroscopy 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Cited by 11 publications

References 16 publications

UV‐resonance Raman micro‐spectroscopy to assess residual chromophores in cellulosic pulps

UV‐resonance Raman micro‐spectroscopy to assess residual chromophores in cellulosic pulps

Thermal Transformation of Caffeic Acid on the Nanoceria Surface Studied by Temperature Programmed Desorption Mass-Spectrometry, Thermogravimetric Analysis and FT–IR Spectroscopy

Impact of Hot-Water Extraction on Acetone-Water Oxygen Delignification of Paulownia Spp. and Lignin Recovery

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Detection of muconic acid type structures in oxidised lignins using 2D NMR spectroscopy 10^th EWLP, Stockholm, Sweden, August 25–28, 2008