Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, 100083, China.
Int J Biol Macromol. 2020 Feb 1;144:596-602. doi: 10.1016/j.ijbiomac.2019.12.080. Epub 2019 Dec 16.
To maximize the utilization of Abaca lignin in the current biorefinery, structural characteristics of native lignin from Abaca were firstly comprehensively investigated. Parallelly, effective delignification of Abaca was achieved by alkaline hydrogen peroxide (AHP) process, which facilitated the production of specialty paper in industry. The structural changes of lignin macromolecules during the AHP delignification were illustrated by comparing the structural differences of the released lignin fraction and corresponding native lignin, which were analyzed via the advanced analytical methods, such as 2D-HSQC NMR, P NMR, pyrolysis-GC/MS, and GPC techniques. It was found that Abaca lignin is a HGS-type lignin, which is overwhelmingly composed of β-O-4 linkages and abundant hydroxycinnamic acids (mainly p-coumaric acid). In addition, partial cleavage of β-O-4 linkages and p-coumarate in lignin occurred during the AHP delignification process. Meanwhile, AHP process also led to the elevation of H-type lignin units in AHPL. Considering that β-O-4 bond is vulnerable in the catalytic degradation process of lignin, the lignin with abundant β-O-4 linkages is beneficial to the downstream conversion of lignin into aromatic chemicals.
为了在当前的生物炼制厂中最大限度地利用麻纤维木质素，首先全面研究了麻纤维木质素的结构特征。同时，通过碱性过氧化氢（AHP）工艺实现了麻纤维的有效脱木质素，这有助于工业特种纸的生产。通过比较释放的木质素馏分和相应的天然木质素的结构差异，说明了木质素大分子在 AHP 脱木质素过程中的结构变化，并用 2D-HSQC NMR、P NMR、热解-GC/MS 和 GPC 等先进分析方法对其进行了分析。结果表明，麻纤维木质素是一种 HGS 型木质素，主要由β-O-4 键和丰富的羟基肉桂酸（主要是对香豆酸）组成。此外，在 AHP 脱木质素过程中，木质素中的β-O-4 键和对香豆酸发生了部分断裂。同时，AHP 工艺还导致 AHPL 中 H 型木质素单元的增加。考虑到β-O-4 键在木质素的催化降解过程中很脆弱，富含β-O-4 键的木质素有利于木质素下游转化为芳香族化学品。
