title: On the formation of lignin polysaccharide networks in Norway spruce.
abstract: In this study we were mirroring suggested in vivo phenomena of lignin-hemicellulose complex formation in vitro, by cross-linking Norway spruce (Picea abies) galactoglucomannans, xylans and lignin moieties to high molecular weight complexes by laccase treatment. We were able to observe the oxidation and cross-linking of non-condensed guaiacyl-type phenolic moieties attached to both of the hemicelluloses by (31)P NMR and size-exclusion chromatography. We suggest that hemicelluloses-lignin complexes form covalently linked structural units during the early stages of lignification via radical enzymatic cross-linking catalyzed by laccase. This work shows that the hemicellulose molecules in wood are covalently linked to two or more lignin units thereby making them suited for forming network structures.
authors.affiliation: Wallenberg Wood Science Centre (WWSC), School of Chemistry, KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Petri
authors.initials: P
authors.lastname: Oinonen
authors.affiliation: Wallenberg Wood Science Centre (WWSC), School of Chemistry, KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Wallenberg Wood Science Centre (WWSC), School of Chemistry, KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Lawoko
authors.affiliation: Wallenberg Wood Science Centre (WWSC), School of Chemistry, KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden. Electronic address: ghenrik@kth.se.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Henriksson
mesh_terms: D042845:Laccase / Q000378:metabolism; D008031:Lignin / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D008351:Mannans / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D009664:Norway; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D028222:Picea / Q000737:chemistry* / Q000378:metabolism; D011134:Polysaccharides / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D008351:Mannans; D011134:Polysaccharides; C443804:galactoglucomannan; C007916:hemicellulose; D008031:Lignin; D042845:Laccase
keywords: Arabinoxylan; Crosslinking; Galactoglucomannan; Laccase; Lignification; Lignin–carbohydrate networks; Norway spruce