A supramolecular proposal of lignin structure and its relation with the wood properties

Abreu, H.S.; Latorraca, J. V. F.; Pereira, Regina Paula Willemen; Monteiro, Maria Beatriz de Oliveira; Abreu, Fábio A; Amparado, Kelysson F

doi:10.1590/s0001-37652009000100014

Cited by 30 publications

(18 citation statements)

References 8 publications

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“…Lignin in hardwoods is constituted mainly by guaiacyl and syringyl units (GS-lignin), with a methoxyl content of 21%, and the β-O-4′ as the most common linkage, with a proportion of 71% or higher of the intermonomeric linkages [81,102,103].…”

Section: Wood Of Angiospermsmentioning

confidence: 99%

Compositional Variability of Lignin in Biomass

Lourenço¹,

Pereira²

2018

Lignin - Trends and Applications

100

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The objective of this chapter is to provide a concise overview of lignin composition and structure in different species and materials (wood, barks and nonwood plants). It includes a brief review on the lignin precursors and their polymerization as well as of the analytical tools used for lignin characterization from wet chemical to spectroscopic methods. Wood of gymnosperms is characterized by high lignin content (25-35%) and a HG-type of lignin with more guaiacyl (G) units and a small portion of p-hydroxyphenyl (H) units. Wood of angiosperms has a lignin content of 15-28%, with a GS-lignin having different proportions of syringyl (S) units. Nonwoody monocotyledon species have different lignin content (9-20%) and a HGS type of lignin, characterized by a high proportion of H units. Bark lignin content ranges from 13 to 43% and is of HGS-type with species-specific composition and different in the bark components, phloem and cork. Lignin composition and macromolecular structure are key issues to understand the properties of lignocellulosic materials and to design a lignin-based pathway within biomass biorefineries. The available information on lignin composition is still limited to a few species and plant components. This is certainly an area where more research is needed.

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Section: Wood Of Angiospermsmentioning

confidence: 99%

Compositional Variability of Lignin in Biomass

Lourenço¹,

Pereira²

2018

Lignin - Trends and Applications

100

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“…However, the helical structure of lignin is quite unlike that of DNA, since there is neither sequence-specific complementarity of DNA nor are the bonds similar. Lignins have a high content of β-O-4 (alkyl aryl ether) bonds ( Figure 5) resulting in the polymer adopting a spiral, quasi-helical conformation that is dependent on its syringyl content [139]. Therefore, one might expect guaiacyl-syringyl lignins of angiosperms to display more coiled spiral conformation with a greater longitudinal expansion relative to gymnosperm lignins, which have a higher content of β-β and β-5 bonds ( Figure 5).…”

Section: Lignin Conformationmentioning

confidence: 99%

Supramolecular Self-Assembled Chaos: Polyphenolic Lignin’s Barrier to Cost-Effective Lignocellulosic Biofuels

et al. 2010

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Phenylpropanoid metabolism yields a mixture of monolignols that undergo chaotic, non-enzymatic reactions such as free radical polymerization and spontaneous selfassembly in order to form the polyphenolic lignin which is a barrier to cost-effective lignocellulosic biofuels. Post-synthesis lignin integration into the plant cell wall is unclear, including how the hydrophobic lignin incorporates into the wall in an initially hydrophilic milieu. Self-assembly, self-organization and aggregation give rise to a complex, 3D network of lignin that displays randomly branched topology and fractal properties. Attempts at isolating lignin, analogous to archaeology, are instantly destructive and nonrepresentative of in planta. Lack of plant ligninases or enzymes that hydrolyze specific bonds in lignin-carbohydrate complexes (LCCs) also frustrate a better grasp of lignin. Supramolecular self-assembly, nano-mechanical properties of lignin-lignin, ligninpolysaccharide interactions and association-dissociation kinetics affect biomass deconstruction and thereby cost-effective biofuels production. OPEN ACCESSMolecules 2010, 15 8642

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“…29 In contrast, softwood lignin, containing mainly guaiacyl (G) phenolic units, is of lower -O-4 bond content with a higher abundance of branched structures, making it more cross-linked. Therefore, it is not surprising that the dilute acid pretreatment of hardwood and softwood in ILs offered different results.…”

Section: P Nmr Analyses Of Wood Components Present Within Recycled Iomentioning

confidence: 99%

Acidolysis of Wood in Ionic Liquids

Filpponen

Argyropoulos

2010

Ind. Eng. Chem. Res.

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Three wood species including Eucalyptus grandis (E. grandis), Southern pine (S. pine), and Norway spruce thermomechanical pulp (N. spruce TMP) were dissolved in the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride ([Amim]Cl), and then they were pretreated with small amounts of hydrochloric acid, as a function of time. The materials regenerated from the IL solutions were determined to contain significantly higher amounts of lignin than the original wood. Detailed analyses of the recovered IL revealed the presence of typical wood degradation compounds, such as 5-hydroxymethylfurfural, furan-2-carboxylic acid, catechol, methylcatechol, methylguaiacol, acetoguaiacone, and acetol. The acidic pretreatment of these wood species in IL resulted in not only the near-complete hydrolysis of cellulose and hemicelluloses but also in a significant amount of lignin degradation. Aqueous reactions (under identical acid concentrations) showed a remarkably lower efficiency, demonstrating that ILs offer a unique environment for the acid-catalyzed dehydration chemistry, which is known to occur when polysaccharides and/or wood are subjected to an acid treatment.

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A supramolecular proposal of lignin structure and its relation with the wood properties

Cited by 30 publications

References 8 publications

Compositional Variability of Lignin in Biomass

Compositional Variability of Lignin in Biomass

Supramolecular Self-Assembled Chaos: Polyphenolic Lignin’s Barrier to Cost-Effective Lignocellulosic Biofuels

Acidolysis of Wood in Ionic Liquids

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