毛竹竹青和竹黄半纤维素的提取与结构表征  

Isolation and Characterization of Hemicellulose from Moso Bamboo Green and Bamboo Yellow

作　　者：黄曹兴[1] 何娟[1] 闵斗勇[2] 李鑫[1] 勇强[1] 

机构地区：[1]南京林业大学化学工程学院,江苏南京210037 [2]南京林业大学轻工科学与工程学院,江苏南京210037

出　　处：《林产化学与工业》2015年第5期29-36,共8页Chemistry and Industry of Forest Products

基　　金：'十二五'国家科技支撑计划资助项目(2015BAD15B09);江苏省高校优势学科建设工程资助项目(无编号);江苏省属高校自然科学研究项目(14KJB220006)

摘　　要：以毛竹加工剩余物为原料,分离出竹青和竹黄。经粉碎过筛、苯/乙醇脱蜡和次氯酸钠脱木质素3个过程得到相应的综纤维素,然后用1%、5%和10%的KOH依次提取综纤维素得到半纤维素,竹青、竹黄半纤维素的总提取率分别为81.74%和85.36%。对所提取的半纤维素进行成分分析、分子量测定、红外光谱和核磁共振分析,结果表明,竹青、竹黄半纤维素成分主要为木糖,分别占61.02%~73.76%和65.22%~80.00%。竹黄半纤维素的重均分子质量为44 870~48 560 g/mol,高于竹青半纤维素的重均分子质量（43 970~46 245 g/mol）。竹青、竹黄碱溶半纤维素都是典型的阿拉伯糖基木聚糖结构,主链为β-D-吡喃木糖形成的木聚糖,在木糖基的C-2位连接着4-O-甲基-α-D-葡萄糖醛酸,C-3位连有α-L-呋喃阿拉伯糖,同时部分木质素通过苯苷键与半纤维素中的糖基相连。Bamboo green and bamboo yellow separated from Moso bamboo residues were delignified by Na Cl O2 after grinded,sifted and dewaxed by toluene-ethanol to achieve holocellulose. The resulted holocellulose was constantly extracted with 1%,5%and 10% KOH to obtain hemicellulose. The yields of hemicellulose acquired from bamboo green and bamboo yellow were calculated as 81. 74% and 85. 36%,respectively. Then,the chemical compositions and structures of these hemicelluloses were characterized by HPAEC,GPC,FT-IR,1H NMR and 2D HSQC techniques. The results indicated that the proportions of xylose in the bamboo green and bamboo yellow hemicellulose preparations were 61. 02%- 73. 76% and 65. 22%- 80. 00%,respectively. The weight average molecular weight of hemicellulose preparations of bamboo yellow were 44 870- 48 560 g / mol,which were higher than that of bamboo green hemicellulose preparations（ 43 970- 46 245 g / mol）. It was demonstrated that the back chain of hemicelluloses were composed of β-D-xylan. Meanwhile,α-L-arabinofuranose and 4-O-methyl-α-D-glucuronic acid were linked to back chain of hemicellulose at C-3 and C-2 of xylan,respectively,and part of lignins were linked to hemicelluloses by phenyl glucoside bond.

关 键 词：竹青 竹黄 半纤维素 结构表征 核磁共振 

分 类 号：TQ35[化学工程]