新型木质素模型物平台构建及其调控机制研究

项目名称： 新型木质素模型物平台构建及其调控机制研究

项目编号： No.31470606

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 林学

项目作者： 张学铭

作者单位： 北京林业大学

项目金额： 88万元

中文摘要： 木质素是仅次于纤维素的天然高分子化合物，由苯丙烷单元愈创木基、紫丁香基和对羟苯基主要以β-O-4, β-5和5-5等键连接的网状结构大分子，它可以转化为生物燃料及化工原料。但由于对木质素生物合成途径及其单元间键合机制仍不明确，限制了木质素高值转化及利用。本项目拟开展新型木质素模型物平台构建及其调控机制的研究。以木质素单体松柏醇及阿魏酸为起始物，模拟细胞壁生长环境并结合化学合成法，合成不同结构的木质素多聚体模型化合物。基于GC-MS、HPLC、XRD、1H-NMR，13C-NMR，2D-HSQC和2D-HMBC等分析手段解译合成模型物结构，揭示木质素多聚体的合成途径与机理，阐明其调控反应机制。利用合成的木质素模型化合物，结合全溶二维核磁分析技术，探索天然木质素大分子结构性质及键合机制，解译木质素-碳水化合物单元间连接键类型及数量，建立半纤维素与木质素键合模型，为木质素高值化利用奠定理论基础。

中文关键词： 木质素；模型化合物；合成；核磁共振；机理研究

英文摘要： Lignin is the second abundant and important natural plant biopolymers next to cellulose, which accounts for approximately 30% of the organic carbon in the biosphere. It is an amorphic three-dimensional substance with internal linkage of β-O-4, β-5 and 5-5, which is the phenylpropanoid polymers produced primarily from oxidative polymerization of three 4-hydroxycinnamyl alcohols differing in their degrees of methoxylation. Lignin can be converted into biofuels and chemical materials. As a highly abundant natural polymer, the biosynthesis of lignins and its chemical/mechanical properties, have attracted significant attention for decades. However, because of its complexity and heterogeneity, it has been a most challenging problem for scientists to understand the composition and structure of lignin, to some extent, which also hinders the research of high-value utilization of lignin. Lignin model compounds, which could be used as reference standard compounds, plays essential roles in the lignin structural analysis. In this study, we have synthesized a series of lignin model compound with coniferyl alcohol and ferulic acid as starting materials. The synthetic pathways and reaction mechanism were revealed based on the NMR characterization and analysis of chemical degradation analysis and GC-MS, HPLC and XRD determination. In addition, the virgin lignin structure was also investigated using 2 D NMR based on complete dissolution in DMSO/pyridine or DMSO/NMI. Moreover, the linkages between lignin and hemicelluloses were also studied.

英文关键词： lignin;model compound;synthesis;NMR;mechanism