摘要
利用水提醇沉法提取大白桩菇粗多糖,用酸性乙醇分级、Sepharose CL-4B以及Sephadex G-100柱层析分离纯化得到大白桩菇多糖(DBZG_(4-b))。采用高效液相色谱法检测DBZG_(4-b)均一性及相对分子质量。经气相色谱、纸层析、红外光谱、甲基化、气相色谱-质谱、核磁共振方法解析DBZG_(4-b)的结构。结果显示,DBZG_(4-b)为均一性多糖,相对分子质量约为6 864;DBZG_(4-b)为多分支结构多糖,主链由Glc和Gal构成,均以1→6糖苷键连接,Glc在3位上有分支,Gal在4位上有分支;支链由Ara、Glc、Gal构成,其中Ara以1→3连接,Glc以1→3连接,Gal以1→4连接,Ara、Xyl、Rha、Man、Glc、Gal都有一部分构成分子的末端残基。清除·OH与1,1-二苯基-2-三硝基苯肼自由基实验表明,DBZG_(4-b)具有良好的清除自由基能力。
Crude polysaccharide was extracted from the fruit bodies of Leucopaxillus giganteus by water extraction and alcohol precipitation and was purified through sequential steps： acidic ethanol fractionation, Sepharose CL-4B and Sephadex G-100 gel filtration chromatography to homogeneity as confirmed by high performance liquid chromatography（HPLC）. The purified polysaccharide was designated as DBZG（4-b） and its molecular weight was measured by HPLC. Moreover, the structure of DBZG（4-b） was elucidated by means of gas chromatography, paper chromatography, infrared（IR） spectroscopy, gas chromatography-mass spectrometry after methylation, and nuclear magnetic resonance（NMR）. Results showed that the average relative molecular weight of the homogeneous polysaccharide, DBZG（4-b）, was 6 864. Its main chains were composed of Glc and Gal, and both of them were conjugated to 1→6 glycoside bond; Glc was substituted at 3-O while Gal was substituted at 4-O. The side chain was composed of（1→3）-Ara,（1→3）-Glc, and（1→4）-Gal. The terminal residue was made up of Ara, Xyl, Rha, Man, Glc and Gal. Furthermore, DBZG（4-b） had significant scavenging potential against hydrolxyl and DPPH free radicals.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2016年第6期71-76,共6页
Food Science
基金
中央民族大学一流大学一流学科建设项目(YLDX01013)
"111创新引智计划"工程项目(B08044)
准格尔北部生态保育技术集成与示范项目(2014BAC15B04)
北京市大学生科学研究与创业行动计划项目(BEIJ2013110009)
关键词
大白桩菇
多糖
分离纯化
结构
自由基
Leucopaxillus giganteus
polysaccharide
isolation and purification
structure
free radicals
