title: Dehydrogenative polymerization of coniferyl alcohol in artificial polysaccharides matrices: effects of xylan on the polymerization.
abstract: To elucidate the influence of wood polysaccharide components on lignin formation in vitro, models for polysaccharide matrix in wood secondary cell wall were fabricated from two types of bacterial cellulosic films, flat film (FBC) and honeycomb-patterned film (HPBC), as basic frameworks by depositing xylan onto the films. An endwise type of dehydrogenative polymerization, "Zutropfverfahren", of coniferyl alcohol was attempted in the films with/without xylan. The resultant dehydrogenation polymer (DHP) was generated inside and outside xylan-deposited films, whereas DHP was deposited only outside the films without xylan. The amount of the generated DHP in the xylan-deposited films was larger than that in the films without xylan. The frequency of 8-O-4' interunitary linkage in DHP was also increased by the xylan deposition. These results suggest that xylan acts as a scaffold for DHP deposition in polysaccharides matrix and as a structure regulator for the formation of the 8-O-4' linkage. In addition, mechanical properties, i.e., tensile strength and modulus of elasticity (MOE), of both cellulosic films were found to be augmented by the deposition of xylan and DHP. Especially, DHP deposition remarkably enhanced MOE. Such effects of xylan on DHP formation and augmentation of mechanical strength were clearly observed for HPBC, revealing that HPBC is a promising framework model to investigate wood cell wall formation in vitro.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Keiichi
authors.initials: K
authors.lastname: Koda
authors.affiliation: §Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Arata
authors.initials: A
authors.lastname: Yoshinaga
authors.affiliation: §Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Takabe
authors.affiliation: ⊥Faculty of Photonic Science, Chitose Institute of Science and Technology, 758-65 Bibi, Chitose 066-8655, Japan.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Shimomura
authors.affiliation: ⊥Faculty of Photonic Science, Chitose Institute of Science and Technology, 758-65 Bibi, Chitose 066-8655, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hirai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tamai
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Uraki
mesh_terms: D004548:Elasticity; D008031:Lignin / Q000737:chemistry*; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013718:Tensile Strength; D014990:Xylans / Q000737:chemistry*
chemical_list: D010636:Phenols; D011108:Polymers; D014990:Xylans; D008031:Lignin; C010559:coniferyl alcohol
keywords: 8-O-4′ linkage; dehydrogenation polymer; honeycomb-patterned bacterial cellulose film; mechanical property; xylan