title: NMR Assignment for Diaryl Ether Structures (4-O-5 Structures) in Pine Wood Lignin.
abstract: A 4-O-5-tetramer lignin model compound carrying β-O-4 linkages on each of the side-chain moieties was synthesized, as well as 4-O-5-coupled dehydrodiconiferyl alcohol. By comparison with their NMR data, two cross-signals in the HSQC spectrum of pine milled wood lignin recorded in DMSO-d6 were assigned to H2/C2 and H6/C6 correlations on the aromatic rings of 4-O-5-linked units. Although the H2/C2 correlation peak appeared in the same region as syringyl units, nitrobenzene oxidation of the pine lignin did not yield any syringyl-type product, but did release a 4-O-5-type product.
authors.affiliation: Wood Chemistry Laboratory, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yanding
authors.initials: Y
authors.lastname: Li
authors.affiliation: Wood Chemistry Laboratory, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.|Japan Science and Technology Agency (JST), PRESTO, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: Wood Chemistry Laboratory, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Wood Chemistry Laboratory, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsumoto
mesh_terms: D029662:Betula / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004987:Ethers; D008031:Lignin / Q000138:chemical synthesis / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000191:economics; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D028223:Pinus / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014934:Wood / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D004987:Ethers; D009578:Nitrobenzenes; D012997:Solvents; D008031:Lignin; C036077:nitrobenzene