Structural and physicochemical characterization of hemicelluloses isolated by alkaline peroxide from barley straw
Structural and physicochemical characterization of hemicelluloses isolated by alkaline peroxide from barley straw
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DOI：
10.1002/pi.815
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发表时间：
2002-02
影响因子：
3.2
通讯作者：
R. Sun;X.F Sun;G.-Q. Liu;P. Fowler;J. Tomkinson
中科院分区：
文献类型：
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作者：
R. Sun;X.F Sun;G.-Q. Liu;P. Fowler;J. Tomkinson
通过用1.5%H2O2在pH 12.0下在45 °C下提取14小时从大麦杆获得七种半纤维素制剂，其中提取剂与麦杆的比率为10：1、13：1、15：1、18：1、20：1、25：1和30：1。溶解的半纤维素的相应产率为28.4重量%、28.8重量%、29.7重量%、30.1重量%、30.6重量%、30.8重量%和30.8重量%或干大麦秆，对应于原始半纤维素的78.7%、79.8%、82.3%、83.4%、84.8%、85.3%和85.3%的释放。聚合物主要由木糖、阿拉伯糖、葡萄糖、半乳糖和4-O-甲基-D-葡萄糖醛酸组成（59.3- 62.6%，19.7- 22.0%，8.8- 12.5%，5.6-6.9%和5.8- 6.7%，重均分子量在38 470和41 050 g mol-1之间。13 CNMR光谱证实了通过化学方法获得的结果，半纤维素组分主要由L-阿拉伯-（4-O-甲基-D-葡萄糖醛酸）-D-木聚糖组成。更重要的是，发现木质素为大麦秆中的半纤维素提供了一些保护，以防止过氧化氢的攻击。© 2002化学工业协会
Seven hemicellulosic preparations were obtained from barley straw by extraction with 1.5% H2O2 at pH 12.0 for 14 h at 45 °C with extractant to straw ratios of 10:1, 13:1, 15:1, 18:1, 20:1, 25:1 and 30:1. The respective yields of dissolved hemicelluloses were 28.4 wt%, 28.8 wt%, 29.7 wt%, 30.1 wt%, 30.6 wt%, 30.8 wt% and 30.8 wt% or dry barley straw, corresponding to release of 78.7%, 79.8%, 82.3%, 83.4%, 84.8%, 85.3% and 85.3% of the original hemicelluloses. The polymers were mainly composed of xylose, arabinose, glucose, galactose and 4-O-methyl-D-glucuronic acid (59.3–62.6%, 19.7–22.0%, 8.8–12.5%, 5.6–6.9% and 5.8–6.7%, respectively) and had weight-average molecular weights of between 38 470 and 41 050 g mol−1.13 CNMR spectroscopy confirmed the results obtained by chemical methods, and showed that the hemicellulosic fraction was mostly by L-arabino-(4-O-methyl-D-glucurono)-D-xylan. More importantly, it was found that lignin provides some protection for the hemicelluloses in barley straw against attack by hydrogen peroxide. © 2002 Society of Chemical Industry