Isolation and fractionation of hemicelluloses by graded ethanol precipitation from Caragana korshinskii
Isolation and fractionation of hemicelluloses by graded ethanol precipitation from Caragana korshinskii
复制标题
通过分级乙醇沉淀从柠条中分离和分级半纤维素
DOI：
10.1016/j.carres.2010.01.014
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发表时间：
2010-04-19
影响因子：
3.1
通讯作者：
Sun, Run-Cang
中科院分区：
文献类型：
--
作者：
Bian, Jing;Peng, Feng;Sun, Run-Cang
锦鸡儿半纤维素用10%KOH在25℃下脱木素10h后分离得到。在乙醇浓度分别为10%、20%、30%、45%、60%和80%的条件下，用分级沉淀法对碱提半纤维素进行分级分级。6个半纤维素亚组分的中性糖和相对分子质量分析表明，在不同乙醇浓度下得到的半纤维素组分的相对分子质量和沿木聚糖主干的支链分布是不同的。乙醇浓度越低，大分子支化半纤维素越少，而乙醇浓度越高，得到的小分子支化半纤维素越多。H-1和C-13核磁共振研究表明，在乙醇浓度为45%时沉淀的半纤维亚组分含有D-木糖残基，并主要通过4-O-甲基-α-D-吡喃葡萄糖基支化。(C)2010爱思唯尔有限公司。保留所有权利。
Caragana korshinskii hemicelluloses were isolated with 10% KOH at 25 degrees C for 10 h from the delignified materials. The alkali-extractable hemicelluloses were then successively sub-fractionated by graded precipitation at final ethanol concentrations of 10%, 20%, 30%, 45%, 60%, and 80%, respectively. Neutral sugars and molecular weight analyses of the six hemicellulosic subfractions revealed that the molecular weights and the distribution of branches along the xylan backbone are different among the hemicellulosic fractions obtained in various ethanol concentrations. The less branched hemicelluloses with large molecules were precipitated in lower ethanol percentages, while with the increasing ethanol concentrations, more branched hemicelluloses with low molecular weights were obtained. H-1 and C-13 NMR studies revealed that the hemicellulosic subfraction precipitated at an ethanol concentration of 45% had a backbone of D-xylose residues and were branched mainly through 4-O-methyl-alpha-D-glucopyranosyl units. (C) 2010 Elsevier Ltd. All rights reserved.