Browse
Submit Data
Databases
API
Help

Dataset Information

11 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Direct evidence for ? ether linkage between lignin and carbohydrates in wood cell walls.

ABSTRACT: Cross-linking between lignin and polysaccharide in plant cell-wall determines physical, chemical, and biological features of lignocellulosic biomass. Since Erdmann's first report in 1866, numerous studies have suggested the presence of a bond between hemicelluloses and lignin; however, no clear evidence for this interaction has been reported. We describe the first direct proof of covalent bonding between plant cell-wall polysaccharides and lignin. Nuclear magnetic resonance spectroscopy was used to observe the long-range correlations through an ?-ether bond between lignin and the primary hydroxyl group of a mannose residue in glucomannan. Complete signal assignment of the cognate structural units was also achieved. Thus, we identified lignin-carbohydrate bonds by complete connectivity analysis from the phenylpropane unit to the carbohydrate moiety.

SUBMITTER: Nishimura H

PROVIDER: S-EPMC5916878 | biostudies-other | 2018 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Direct evidence for α ether linkage between lignin and carbohydrates in wood cell walls.

Nishimura Hiroshi H Kamiya Akihiro A Nagata Takashi T Katahira Masato M Watanabe Takashi T

Scientific reports 20180425 1

Cross-linking between lignin and polysaccharide in plant cell-wall determines physical, chemical, and biological features of lignocellulosic biomass. Since Erdmann's first report in 1866, numerous studies have suggested the presence of a bond between hemicelluloses and lignin; however, no clear evidence for this interaction has been reported. We describe the first direct proof of covalent bonding between plant cell-wall polysaccharides and lignin. Nuclear magnetic resonance spectroscopy was used ...[more]

PMID: 29695732

Similar Datasets

Lignin-Retaining Transparent Wood.

Project description:Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30?wt?% of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80?wt?% of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83?%, haze of 75?%, thermal conductivity of 0.23?W?mK-1 , and work-tofracture of 1.2?MJ?m-3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings.

| S-EPMC5601211 | biostudies-literature

Acridine Orange Indicates Early Oxidation of Wood Cell Walls by Fungi.

Project description:Colonization of wood blocks by brown and white rot fungi rapidly resulted in detectable wood oxidation, as shown by a reduced phloroglucinol response, a loss of autofluorescence, and acridine orange (AO) staining. This last approach is shown to provide a novel method for identifying wood oxidation. When lignin was mildly oxidized, the association between AO and lignin was reduced such that stained wood sections emitted less green light during fluorescence microscopy. This change was detectable after less than a week, an interval that past work has shown to be too short for significant delignification of wood. Although fungal hyphae were observed in only a few wood lumina, oxidation was widespread, appearing relatively uniform over regions several hundred micrometers from the hyphae. This observation suggests that both classes of fungi release low molecular weight mild oxidants during the first few days of colonization.

| S-EPMC4959780 | biostudies-literature

Lignin-polysaccharide interactions in plant secondary cell walls revealed by solid-state NMR.

Project description:Lignin is a complex aromatic biopolymer that strengthens and waterproofs plant secondary cell walls, enabling mechanical stability in trees and long-distance water transport in xylem. Lignin removal is a key step in paper production and biomass conversion to biofuels, motivating efforts to re-engineer lignin biosynthesis. However, the physical nature of lignin's interactions with wall polysaccharides is not well understood. Here we show that lignin self-aggregates to form highly hydrophobic and dynamically unique nanodomains, with extensive surface contacts to xylan. Solid-state NMR spectroscopy of intact maize stems, supported by dynamic nuclear polarization, reveals that lignin has abundant electrostatic interactions with the polar motifs of xylan. Lignin preferentially binds xylans with 3-fold or distorted 2-fold helical screw conformations, indicative of xylans not closely associated with cellulose. These findings advance our knowledge of the molecular-level organization of lignocellulosic biomass, providing the structural foundation for optimization of post-harvest processing for biofuels and biomaterials.

| S-EPMC6341099 | biostudies-literature

Linkage Memory in Underivatized Protonated Carbohydrates.

Project description:Carbohydrates are among the most complex class of biomolecules, and even subtle variations in their structures are attributed to diverse biological functions. Mass spectrometry has been essential for large scale glycomics and glycoproteomics studies, but the gas-phase structures and sometimes anomalous fragmentation properties of carbohydrates present long-standing challenges. Here we investigate the gas-phase properties of a panel of isomeric protonated disaccharides differing in their linkage configurations. Multiple conformations were evident for most of the structures based on their fragment ion abundances by tandem mass spectrometry, their ion mobilities in several gases, and their deuterium uptake kinetics by gas-phase hydrogen-deuterium exchange. Most notably, we find that the properties of the Y-ion fragments are characteristically influenced by the precursor carbohydrate's linkage configuration. This study reveals how protonated carbohydrate fragment ions can retain "linkage memory" that provides structural insight into their intact precursor.

| S-EPMC8136833 | biostudies-literature

Lignin degradation in wood-feeding insects.

Project description:The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of A. glabripennis identified a single species of fungus in the Fusarium solani/Nectria haematococca species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects.

| S-EPMC2529026 | biostudies-literature

Nucleophilic Thiols Reductively Cleave Ether Linkages in Lignin Model Polymers and Lignin.

Project description:Lignin may serve as a renewable feedstock for the production of chemicals and fuels if mild, scalable processes for its depolymerization can be devised. The use of small organic thiols represents a bioinspired strategy to cleave the ?-O-4 bond, the most common linkage in lignin. In the present study, synthetic ?-O-4 linked polymers were treated with organic thiols, yielding up to 90?% cleaved monomer products. Lignin extracted from poplar was also treated with organic thiols resulting in molecular weight reductions as high as 65?% (Mn ) in oxidized lignin. Thiol-based cleavage of other lignin linkages was also explored in small-molecule model systems to uncover additional potential pathways by which thiols might depolymerize lignin. The success of thiol-mediated cleavage on model dimers, polymers, and biomass-derived lignin illustrates the potential utility of small redox-active molecules to penetrate complex polymer matrices for depolymerization and subsequent valorization of lignin into fuels and chemicals.

| S-EPMC7540407 | biostudies-literature

A versatile click-compatible monolignol probe to study lignin deposition in plant cell walls.

Project description:Lignin plays important structural and functional roles in plants by forming a hydrophobic matrix in secondary cell walls that enhances mechanical strength and resists microbial decay. While the importance of the lignin matrix is well documented and the biosynthetic pathways for monolignols are known, the process by which lignin precursors or monolignols are transported and polymerized to form this matrix remains a subject of considerable debate. In this study, we have synthesized and tested an analog of coniferyl alcohol that has been modified to contain an ethynyl group at the C-3 position. This modification enables fluorescent tagging and imaging of this molecule after its incorporation into plant tissue by click chemistry-assisted covalent labeling with a fluorescent azide dye, and confers a distinct Raman signature that could be used for Raman imaging. We found that this monolignol analog is incorporated into in vitro-polymerized dehydrogenation polymer (DHP) lignin and into root epidermal cell walls of 4-day-old Arabidopsis seedlings. Incorporation of the analog in stem sections of 6-week-old Arabidopsis thaliana plants and labeling with an Alexa-594 azide dye revealed the precise locations of new lignin polymerization. Results from this study indicate that this molecule can provide high-resolution localization of lignification during plant cell wall maturation and lignin matrix assembly.

| S-EPMC4401456 | biostudies-literature

Modification of Kraft Lignin with Dodecyl Glycidyl Ether.

Project description:Kraft lignin (KL) is extensively produced in industry but is mainly burned as fuel. To broaden its use, KL was grafted with dodecyl glycidyl ether to alter its thermal properties. The reaction of KL with dodecyl glycidyl ether (DGE) was analyzed using nuclear magnetic resonance (NMR), Fourier infrared spectroscopy (FT-IR) and elemental analysis. Alternatively, KL was methylated to mask its phenolic hydroxy groups to investigate how phenolic hydroxy groups impact the grafting of the alkyl chain of DGE onto lignin (methylated Kraft lignin, MKL). The methylation facilitated the molecular weight enhancement and thermal stability reduction of Kraft lignin via grafting with DGE. The influence of grafting alkyl chains on the structural and thermal properties of KL and MKL was studied using thermogravimetric analysis and differential scanning calorimetry analysis. Our data suggest that, due to their high molecular weights and lower glass transition temperatures, the produced lignin derivatives may be promising feedstocks for composite production.

| S-EPMC6786095 | biostudies-literature

Epigallocatechin gallate incorporation into lignin enhances the alkaline delignification and enzymatic saccharification of cell walls.

Project description:BACKGROUND:Lignin is an integral component of the plant cell wall matrix but impedes the conversion of biomass into biofuels. The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic monomers such as flavonoids into cell wall lignins that are consequently less recalcitrant to biomass processing. In the present study, epigallocatechin gallate (EGCG) was evaluated as a potential lignin bioengineering target for rendering biomass more amenable to processing for biofuel production. RESULTS:In vitro peroxidase-catalyzed polymerization experiments revealed that both gallate and pyrogallyl (B-ring) moieties in EGCG underwent radical cross-coupling with monolignols mainly by ?-O-4-type cross-coupling, producing benzodioxane units following rearomatization reactions. Biomimetic lignification of maize cell walls with a 3:1 molar ratio of monolignols and EGCG permitted extensive alkaline delignification of cell walls (72 to 92%) that far exceeded that for lignified controls (44 to 62%). Alkali-insoluble residues from EGCG-lignified walls yielded up to 34% more glucose and total sugars following enzymatic saccharification than lignified controls. CONCLUSIONS:It was found that EGCG readily copolymerized with monolignols to become integrally cross-coupled into cell wall lignins, where it greatly enhanced alkaline delignification and subsequent enzymatic saccharification. Improved delignification may be attributed to internal trapping of quinone-methide intermediates to prevent benzyl ether cross-linking of lignin to structural polysaccharides during lignification, and to the cleavage of ester intra-unit linkages within EGCG during pretreatment. Overall, our results suggest that apoplastic deposition of EGCG for incorporation into lignin would be a promising plant genetic engineering target for improving the delignification and saccharification of biomass crops.

| S-EPMC3477100 | biostudies-literature

The Effect of High Lignin Content on Oxidative Nanofibrillation of Wood Cell Wall.

Project description:Wood from field-grown poplars with different genotypes and varying lignin content (17.4 wt % to 30.0 wt %) were subjected to one-pot 2,2,6,6-Tetramethylpiperidin-1-yl)oxyl catalyzed oxidation and high-pressure homogenization in order to investigate nanofibrillation following simultaneous delignification and cellulose oxidation. When comparing low and high lignin wood it was found that the high lignin wood was more easily fibrillated as indicated by a higher nanofibril yield (68% and 45%) and suspension viscosity (27 and 15 mPa·s). The nanofibrils were monodisperse with diameter ranging between 1.2 and 2.0 nm as measured using atomic force microscopy. Slightly less cellulose oxidation (0.44 and 0.68 mmol·g-1) together with a reduced process yield (36% and 44%) was also found which showed that the removal of a larger amount of lignin increased the efficiency of the homogenization step despite slightly reduced oxidation of the nanofibril surfaces. The surface area of oxidized high lignin wood was also higher than low lignin wood (114 m2·g-1 and 76 m2·g-1) which implicates porosity as a factor that can influence cellulose nanofibril isolation from wood in a beneficial manner.

| S-EPMC8146676 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data