Aryl-alkyl Ether Linkages in Lignin
نویسندگان
چکیده
منابع مشابه
Restricted Mass Transport Effects on the Pyrolysis Pathways for Lignin Model Compounds. Aryl Ether Linkages
Aryl ethers are important linking units in the structure of lignins and low rank coals that are thermally labile at 375°C. Mass transport limitations experienced in these cross-linked macromolecular solids can lead to alterations in thermochemical processing kinetics and product yields. The molecular level details of these alterations on reaction pathways are revealed through studies of model c...
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This study concerns the structural change of lignin during auto-catalyzed ethanol-water pulping of aspen by 1H-NMR. The results showed that the linkages of alkyl-aryl ether of lignin, such as the α-ether linkages (α-O-4) and the β-ether linkages (β-O-4), were broken and the alkyl part formed carbenium at the Cα and Cβ of the aliphatic branch. Meanwhile, the aryl part of ether accepted one H and...
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Lignin biosynthesis occurs via radical coupling of guaiacyl and syringyl hydroxycinnamyl alcohol monomers (i.e., "monolignols") through chemical condensation with the growing lignin polymer. With each chain-extension step, monolignols invariably couple at their β-positions, generating chiral centers. Here, we report on activities of bacterial glutathione-S-transferase (GST) enzymes that cleave ...
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An efficient tandem synthesis of alkyl aryl ethers, including valuable building blocks of dialdehyde and dinitro groups under microwave irradiation and solvent free conditions on potassium carbonate as a mild solid base has been developed. A series of alkyl aryl ethers were obtained from alcohols in excellent yields by following the Williamson ether synthesis protocol under practical mild condi...
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Lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lign...
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ژورنال
عنوان ژورنال: Communications, Faculty Of Science, University of Ankara Series B Chemistry and Chemical Engineering
سال: 1969
ISSN: 1303-6017
DOI: 10.1501/commub_0000000313