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Isolation of lignin-carbohydrate bonds in wood

木材中木质素-碳水化合物键的分离

基本信息

批准号：
15380124
负责人：
HOSOYA Shuji
金额：
$ 6.72万
依托单位：
Forestry and Forest Products Research Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

Mostly lignin, it is about 96% lignin in wood meal, was degraded to very low molecular weight structures which could not give acid insoluble lignin after ozonation for 16 hours with 20 times molar ozone. On the other hand, LCC products which contain a benzyl ether type LCC bond in a molecular were isolated from red pine wood after ozonation followed by acid hydrolysis. LCC products were included in the Acidic fraction after anion exchange chromatography, the Acidic fraction was mixture of many products such as organic acids from lignin and acidic sugars from polysaccharides. Many products gave similar retention time compare with that of LCC products on GC chromatogram after trimethylsilylation, identification of LCC products was very difficult. However, it was improved after acetylation instead of trimethylsilylation. LCC products were isolated from both glucose and mannose bonded LCC model compounds and some products which give same retention time on GC chromatogram with these LCC products were also isolated from red pine wood. These products isolated from red pine wood gave same retention time on total ion chromatogram and showed similar mass fragment pattern, compared with LCC products isolated from LCC model compounds. Therefore, these results suggested that benzyl ether type LCC bonds between lignin and hexoses, such as glucose and mannose, were isolated from red pine wood by ozonation followed acid hydrolysis without LCC bond cleavage.

在20倍摩尔臭氧作用16小时后，木粉中木质素含量约为96%，大部分木质素被降解为不能产生酸不溶性木质素的极低分子量结构。另一方面，从红松木材中分离出含有苄基醚型LCC键的LCC产物，该产物经臭氧氧化和酸水解得到。经阴离子交换层析后，LCC产品被纳入酸性组分，酸性组分是木质素的有机酸和多糖的酸性糖等多种产物的混合物。经三甲基硅化处理后，许多产品在GC色谱上的保留时间与LCC产品相似，这给LCC产品的鉴定带来了很大的困难。然而，在乙酰化而不是三甲基硅基化后得到了改进。从葡萄糖和甘露糖键合的LCC模型化合物中都分离到了LCC产物，并且从红松木材中也分离到了一些与这些LCC产物具有相同GC色谱保留时间的产物。与从LCC模型化合物中分离得到的LCC产品相比，从红松木中分离得到的产品在总离子色谱上的保留时间相同，质量片段模式相似。因此，这些结果表明，通过臭氧化和酸水解，可以在不破坏LCC键的情况下分离出木质素与己糖（如葡萄糖和甘露糖）之间的苯醚型LCC键。