权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Selective cleavage of ether bonds in lignin

木质素中醚键的选择性断裂

基本信息

批准号：
07456078
负责人：
MESHITSUKA Gyosuke
金额：
$ 4.35万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07456078/
关键词：
lignin lignin structure ether bonds structural heterogeneity ether bond cleavage HASB reagent

项目摘要

Structural heterogeneity of lignin is one of the most important research targets for the full understanding of lignin structure and cell wall formation. In this study, different types of HASB reagents were applied to lignin for the selective and partial cleavage of ehter bonds, particularly beta-ether bonds in lignin. Treatment of periodate lignin with a limited amount of trimethylsilyl iodide gave a very small amount of low molecular weitht lignin fraction which was surprisingly rich in phenylcoumaran structure. In the case of pre-methylated periodate lignin, a very increased amount of low molecular weitht fraction was available which were basically formed by beta-ether linkages. These results strongly indicate the structural heterogeneity of lignin. It is olso interesting to note that the same treatment of a milled wood lignin (MWL) did not give any characteristic lignin fraction. All low molecular weight MWL fractions formed by this treatment tourned out to have quite similar characteristics. This means that MWL itself is a lignin fraction originated from a special morphological region of wood cell walls.Selective cleavage of ether bonds, in particular alpha-ether bonds, was also accomplished for unbleached kraft pulp. It is interesting to note that residual lignin in pulp became more easily extractable after the above treatment. Ether bonds between alpha-carbons of lignin side chains and carbohydrate must be one of the key factors of the resistant nature of lignin in pulp.

木质素的结构异质性是全面了解木质素结构和细胞壁形成的重要研究对象之一。在本研究中，不同类型的HASB试剂被应用于木质素，以选择性和部分切割木质素中的醚键，特别是β -醚键。用一定量的三甲基硅基碘化剂处理高碘酸木质素可以得到极少量的低分子量木质素组分，这些木质素组分惊人地富含苯香豆素结构。在预甲基化高碘酸木质素的情况下，低分子量组分的数量非常多，这些组分基本上是由-醚键形成的。这些结果有力地说明了木质素的结构不均一性。同样有趣的是，对磨木质素（MWL）进行同样的处理并没有给出任何特征木质素分数。经此处理形成的所有低分子量MWL馏分均具有相当相似的特性。这意味着MWL本身是源自木材细胞壁特殊形态区域的木质素组分。对于未漂白的硫酸盐纸浆，也实现了醚键，特别是α -醚键的选择性裂解。有趣的是，经过上述处理，纸浆中的残余木质素变得更容易提取。木质素侧链α -碳与碳水化合物之间的醚键是木质素在纸浆中耐蚀性的关键因素之一。