Bond length of b-O-4 linkage in lignin

• Project/Area Number: 25660130
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Wood science
• Research Institution: The University of Tokyo
• Principal Investigator: Matsumoto Yuji 東京大学, 大学院農学生命科学研究科, 教授 (30183619)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2014: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2013: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: リグニン / バイオマス / 立体構造 / 芳香核 / b-O-4 結合 / 結合様式 / 立体異性体 / 芳香核構造 / 結晶構造解析 / β-エーテル結合 / 反応性 / 結合距離

Outline of Final Research Achievements

The degradation of lignin determines the utilization of woody biomass. As an important factor which controls the lignin degradation, we focused on the cleavage of b-O-4 linkage of lignin. The purpose of this study was to clarify the mechanism of the aromatic structure and side-chain stereo structure of lignin to regulate the cleavage of b-O-4 linkage.
More than 10 kinds of lignin b-O-4 model compounds with different aromatic structure and side-chain structure were synthesized and subjected to alkali treatment under various condition. Results suggested that aromatic structure determines the cleavage of b-O-4 linkage through the degree of ionization of a-hydroxy group and the nucleophilicity of the ionized (dissociated) hydroxy group.