P-32 β-O-4型人工リグニンの合成研究(ポスター発表の部)

概要

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The β-O-4 structure is the most abundant substructure in lignin. Artificial lignin polymers composed exclusively of the β-O-4 structure were prepared from acetophenone derivatives as starting materials. Monomers with two-carbon side chain and with three-carbon side chain were polymerized in the presence of K_2CO_3, and reduced with NaBH_4 to give artificial lignin polymers. Both polymers are linear polymers which resemble natural lignins in their structure. The weight average degree of polymerization (DP_w) was comparable to enzymatically synthesized artificial lignin from p-hydroxycinnamyl alcohols (dehydrogenation polymer, DHP) and some isolated lignins. All artificial lignin polymers were fully characterized by ^1H, ^<13>C and ^1H-^<13>C correlation 2D-NMR spectroscopy. The spectra of guaiacyl-type homopolymer and guaiacyl/syringyl-type heteropolymer with three-carbon side chain were well consistent with β-O-4 substructure in milled wood lignin from Japanese todo fir wood (softwood) and Japanese white birch wood (hardwood), respectively. Using these new lignin model polymers, it will now be possible to reinvestigate the properties and reactivity of the main lignin structure in terms of its polymeric character.
天然有機化合物討論会の論文
2007-08-24