摘要
采用聚酰胺柱层析和乙醇多次沉淀的方法分离纯化,获得燕麦β-葡聚糖主要组分Oglu-1,经HPLC、UV、IR、1HNMR和13CNMR证实Oglu-1为β-D-均聚线型葡聚糖,糖基之间通过β-D-(1→4)和(1→3)糖苷键连接,二者之比为2.1:1,激光光散射测定多糖的相对分子质量为4.49×105。通过测定特性黏度和激光光散射分析建立了Oglu-1水溶液中的Mark-Houwink方程([η]=0.161Mw0.585)和均方根旋转半径-相对分子质量关系模型,证实了Oglu-1分子在溶液中的形态为柔顺性线型高分子链;利用AFM直接观测到Oglu-1是分子链长度约250nm,宽度约为5～10nm,高2～3nm的无支链线型柔顺高分子;CD分析表明,多糖分子量、多糖浓度及pH值、温度等环境因素的改变均可导致溶液中燕麦β-葡聚糖立体构象和非对称性的变化。
Oglu-1, a main constituent of Oglu, was obtained by multiple ethond precipitation and column chromatography. It was found that Oglu-1 is composed of glucose units only and joined by β-D-（1→~4） and β-D-（1→3） linkage with the linkage number ration 2.1：1 by using the methods of UV, IR, ^1HNMR,^13CNMR and HLPC. The average molecular weight of Oglu-1 is 4.49 × 10^5 determined by GPC-LLS. The Oglu-1 is semi-flexible chain,which was proved by the Mark-Houwink equation （[ η ]=0. 161Mw^0.585） and the relation model of Mw-〈S^2〉^1/2. The molecular chain conformation of Oglu-1 was observed directly by AFM, and its length（250 nm）, width（5- 10 nm） and high （2-3 nm） obtained respectively. The CD spectrogram showed that the asymmetry, conformation of Oglu- 1 may be influenced by average molecular weight, pH, and temperature etc.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2008年第10期80-84,共5页
Food Science
基金
湖北省稻谷加工工程技术研究中心基金项目(2007016)
