Fractional isolation and characterization of lignin and hemicelluloses from Triploid of Populus tomentosa Carr.
Fractional isolation and characterization of lignin and hemicelluloses from Triploid of Populus tomentosa Carr.
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DOI：
10.1016/j.indcrop.2009.12.003
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发表时间：
2010-03
影响因子：
5.9
通讯作者：
A. Zhang;Chuanfu Liu;R. Sun
中科院分区：
文献类型：
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作者：
A. Zhang;Chuanfu Liu;R. Sun
以三倍体毛白杨（Populus tomentosa卡尔.）用96：4的二氧六环：水、50：50的二氧六环：水和80：20的二氧六环：水（含有1% NaOH）在85°C下处理产生基于白杨干质量的11.41%木质素和14.78%半纤维素。通过硝基苯氧化、FT-IR、~（31）P NMR和~ 1H-~（13）C ~（2D）NMR等方法对三种木质素组分的结构特征进行了比较研究。结果表明，经中性和碱性二氧六环分离得到的3种木质素组分均为GSH型木质素。在96：4的二氧六环：水、50：50的二氧六环：水和碱性二氧六环木质素提取物中，非缩合的二氧六环基与愈创木基的比率分别为2.7、3.2和1.3。用~（31）PNMR谱测得三个木质素级分的酚羟基含量分别为1.2、0.7和0.87mmol/g。结果还表明，50：50的二氧六环：水木质素提取物含有相对较高量的脂肪族羟基和较低量的非缩合双辛基羟基基团，而不是其他两个级分。
The sequential three-step extraction procedure performed on fast-growing poplar, Triploid of Populus tomentosa Carr., with 96:4 dioxane:water, 50:50 dioxane:water and 80:20 dioxane:water containing 1% NaOH at 85°C yielded 11.41% lignin and 14.78% hemicelluloses based on poplar dry mass. The structural features of the three isolated lignin fractions were comparatively examined by nitrobenzene oxidation, FT-IR,31P NMR and1H–13C 2D NMR spectroscopies. The results showed that the three lignin fractions, isolated sequentially with neutral and alkaline dioxane, were all GSH-type lignin. The ratio of non-condensed syringyl to guaiacyl was 2.7, 3.2, and 1.3 in the 96:4 dioxane:water, 50:50 dioxane:water, and alkaline dioxane lignin extracts, respectively. The contents of phenolic hydroxyl groups in the three lignin fractions obtained from31P NMR spectra were 1.2, 0.7, and 0.87mmol/g, respectively. The results also indicated that the 50:50 dioxane:water lignin extracts contained a relatively higher amount of aliphatic hydroxyls and a lower amount of non-condensed syringyl hydroxyl groups than the other two fractions.