Institute of Biomass Chemistry and Technology, College of Material Science and Technology, Beijing Forestry University, Beijing 100083, China.
Carbohydr Polym. 2013 Feb 15;92(2):2224-31. doi: 10.1016/j.carbpol.2012.11.098. Epub 2012 Dec 10.
Sweet sorghum stem was successively extracted with water at 90 °C, 0.3, 0.6, 1.0, 1.5, and 2.0% KOH aqueous solution, and 60% ethanol containing 2.5% KOH at 75 °C for 3 h, yielding 76.3% of the original hemicelluloses. Chemical composition and structural characterization of the seven hemicellulosic fractions obtained were comparatively investigated by a combination of HPAEC, GPC, FT-IR, (1)H-, (13)C-, HSQC NMR and TGA techniques. According to the spectral analysis, hemicelluloses from sweet sorghum stem are assumed to L-arabino-4-O-methyl-D-glucurono-D-xylan. In addition, the higher molecular weights of hemicelluloses resulted in a higher thermal stability of the samples. The present study suggests that successive alkali extraction is a promising approach for fractionation of hemicelluloses from sweet sorghum stem and to prepare hemicellulosic polymers with different branching and molecular weights.
甜高粱秸秆依次用 90°C 的水、0.3%、0.6%、1.0%、1.5%和 2.0%KOH 水溶液以及 75°C 下含 2.5%KOH 的 60%乙醇进行提取，得到 76.3%的原半纤维素。通过 HPAEC、GPC、FT-IR、（1）H-、（13）C-、HSQC NMR 和 TGA 技术，比较研究了从甜高粱秸秆中获得的七种半纤维素级分的化学组成和结构特征。根据光谱分析，甜高粱秸秆中的半纤维素假定为 L-阿拉伯糖-4-O-甲基-D-葡萄糖醛酸-D-木聚糖。此外，较高的半纤维素分子量导致样品具有更高的热稳定性。本研究表明，连续碱提取是从甜高粱秸秆中分离半纤维素和制备具有不同支化和分子量的半纤维素聚合物的一种很有前途的方法。
