白术多糖WAM-1结构的色谱分析和原子力显微镜观察

通过热水浸提法从草本植物白术根茎提取的水溶性粗多糖,经DEAE-52纤维素柱层析分离和Sephadex G-200凝胶过滤柱层析纯化,得到组分WAM-1.采用高效液相色谱(HPLC)检测WAM-1的纯度,气相色谱(GC)对其单糖组分进行分析,原子力显微镜(AFM)对其分子外貌进行观测.结果显示:WAM-1为均一多糖,由葡萄糖和半乳糖以3.01:1摩尔比构成；在不同浓度溶液条件下,WAM-1分子以不同形态存在,多糖溶液的浓度对WAM-1的分子链构象及链间相互作用形式产生影响,推测可能与WAM-1分子内、分子间的氢键缔合作用有关.多糖浓度为10μg/mL时,可清晰的观察到WAM-1是以刚性链状形态存在,且具有多分支结构.

Chromatographic Analysis and Atomic Force Microscope Observation of Polysaccharide Extracted from Atractylodes macrocephala Koidz.

Polysaccharides extracted from the stem of Atractylodes macrocephala Koidz by hot water,were fractionated by DEAE-52 cellulose chromatography,and purified by Sephadex G-200 gel filtration chromatography to obtain a fraction,named WAM-1.HPLC and GC analysis showed that WAM-1 was a homogeneous and consisted of glucose and galactose in the molar ratio of 3.01∶ 1.The molecular morphology of WAM-1 was observed under an atomic force microscope(AFM).The results showed that WAM-1 existed in different forms with different concentrations.The concentration of polysaccharide had effects on the conformation and form of chain interactions,which might be related to the interaction of intramolecular and intermolecular hydrogen bonds.At 10 μg/mL,the morphology of WAM-1 was observed clearly in rigid chains with many branches.