Proposed supramolecular structure of lignin in softwood tracheid compound middle lamella regions
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Abstract
The structure of lignin in the compound middle lamella (CML) of softwood tracheids differs from that in the secondary wall (SW) in regard to the content of condensed structures (5-5′-biphenyl, dibenzodioxocin and 4-O-5′-diphenyl ether). In an early stage of cell wall formation, random coarse networks composed of thin cellulose microfibrils (CMFs), hemicelluloses, and pectin are formed in the CML, then globular p-hydroxyphenyl/guaiacyl lignin (HG-lignin) is deposited quickly into the network. The globular lignin is assumed to be a micellar aggregate of oligolignols folded at the β-O-4 bond with their phenolic ends on the outer part of the aggregate. When 3D clusters of the globules are deposited on the preformed network of polysaccharides, further growth of the oligolignols by endwise addition of new monolignols is spatially limited, so frequent condensation occurs between growing aromatic ends of adjacent HG-oligolignols within the globule and between the wide contact boundaries of the 3D clustered globules to produce a highly condensed supramolecule in CML. In SW, the folded G-oligolignols are deposited slowly in the narrow tubular space surrounding thick CMFs coated with hemicelluloses. Condensation occurs mostly between adjacent growing ends of the oligolignols within the tubular aggregates. Spatial regulation of condensation of folded polylignols is one of the factors producing a different supramolecular structure for CML lignin than for SW lignin.
©2012 by Walter de Gruyter Berlin Boston
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- Masthead
- Masthead
- Original Papers
- Proposed supramolecular structure of lignin in softwood tracheid compound middle lamella regions
- Degradation products of lignocellulosics in pulp mill effluents – comparison and evaluation of different gas chromatographic techniques for a comprehensive analysis
- Analysis of DCM extractable components from hot-pressed hybrid poplar
- Pretreatment of softwood dissolving pulp with ionic liquids
- Probing the chemical and surface chemical modification of vessel cell walls during bleaching of eucalyptus pulp
- Chemotaxonomical identification of Holocenic bogwood recovered after 2007 Niigataken Chuestsu-oki Earthquake
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- Solvent-free chemical modification of wood by acetic and butyric anhydride with iodine as catalyst
- Synchrotron-based tomographic microscopy (SbTM) of wood: development of a testing device and observation of plastic deformation of uniaxially compressed Norway spruce samples
- Effects of polymeric matrix on accelerated UV weathering properties of wood-plastic composites
- Nano- and microstructures in stretched and non-stretched blend gels of cellulose and hemicelluloses
- Dimensional and hygroexpansive behaviors of cellulose microfibrils (MFs) from kraft pulp-based fibers as a function of relative humidity
- Effect of quat- and amino-silicones on fungal colonisation and decay of wood
- Copper precipitation of Cu-monoethanolamine preservative in wood
- Short Note
- Mode II critical stress intensity factor of wood measured by the asymmetric four-point bending test of single-edge-notched specimen while considering an additional crack length
- Erratum
- Treating birch wood with a switchable 1,8-diazabicyclo-[5.4.0]-undec-7-ene-glycerol carbonate ionic liquid
- Meetings
- Meetings
Articles in the same Issue
- Masthead
- Masthead
- Original Papers
- Proposed supramolecular structure of lignin in softwood tracheid compound middle lamella regions
- Degradation products of lignocellulosics in pulp mill effluents – comparison and evaluation of different gas chromatographic techniques for a comprehensive analysis
- Analysis of DCM extractable components from hot-pressed hybrid poplar
- Pretreatment of softwood dissolving pulp with ionic liquids
- Probing the chemical and surface chemical modification of vessel cell walls during bleaching of eucalyptus pulp
- Chemotaxonomical identification of Holocenic bogwood recovered after 2007 Niigataken Chuestsu-oki Earthquake
- Tensile creep and recovery of Norway spruce influenced by temperature and moisture
- Solvent-free chemical modification of wood by acetic and butyric anhydride with iodine as catalyst
- Synchrotron-based tomographic microscopy (SbTM) of wood: development of a testing device and observation of plastic deformation of uniaxially compressed Norway spruce samples
- Effects of polymeric matrix on accelerated UV weathering properties of wood-plastic composites
- Nano- and microstructures in stretched and non-stretched blend gels of cellulose and hemicelluloses
- Dimensional and hygroexpansive behaviors of cellulose microfibrils (MFs) from kraft pulp-based fibers as a function of relative humidity
- Effect of quat- and amino-silicones on fungal colonisation and decay of wood
- Copper precipitation of Cu-monoethanolamine preservative in wood
- Short Note
- Mode II critical stress intensity factor of wood measured by the asymmetric four-point bending test of single-edge-notched specimen while considering an additional crack length
- Erratum
- Treating birch wood with a switchable 1,8-diazabicyclo-[5.4.0]-undec-7-ene-glycerol carbonate ionic liquid
- Meetings
- Meetings
