转基因西洋参冠瘿组织中多糖的分离和纯化

目的分离纯化转基因西洋参冠瘿组织中多糖组分,为从该转基因材料中寻找重要生物活性前体多糖药物提供科学依据。方法用水醇提取法,以DEAE Sepharose FF和Sephacryl S-100柱色谱进行多糖的分离纯化,采用高效液相色谱测定单糖组成,色谱和光谱学方法鉴定其纯度和化学结构。结果分离得到4个精多糖(PPQ50-1、PPQ50-2、PPQ70-1和PPQ70-2),凝胶色谱法(Sephadex G-200)和旋光法证实了它们为化学均一性多糖;凝胶色谱法测得4种精多糖的相对分子质量分别为4.7×104,2.9×105,7.5×104和1.3×105;对得量较多的PPQ50-2和PPQ70-2进行了结构分析,证明二者均为葡聚糖;并利用NaIO4氧化反应和核磁共振谱等方法对PPQ50-2的化学结构进行了初步的糖基键合分析。结论首次从转基因西洋参冠瘿组织中分离得到4种化学均一性多糖成分,其中PPQ50-2和PPQ70-2均为葡聚糖。

Isolation and purification of polysaccharides from transgenic crown gall cultures of Panax quinquefolium

Objective To investigate the polysaccharides constituents from the transgenic crown gall cultures of Panax quinquefolium. Methods The crude polysaccharides PPQ50 and PPQ70 were extracted by water-ethanol method from the crown gall of P. quinquefolium. Four polysaccharides, named PPQ50-1, PPQ50-2, PPQ70-1, and PQ70-2, were isolated and purified by DEAE Sepharose and Sephacry S-100 column chromatography. Results The homogeneity of four polysaccharides was examined by gel chromatography and polarimetry. Their molecular weights were determined by gel filtration chromatography. They were 4.7×10⁴, 2.9×10⁵, 7.5×10⁴, and 1.3×10⁵, respectively. The sugar composition was analyzed by HPLC. The polysaccharides are mainly composed of neutral sugar particularly of D-glucose. The structure elucidation of PPQ50-2 was also supported by ¹H-NMR and ¹³C-NMR spectroscopy. Conclusion All of the four polysaccharides are first isolated and purified from the transgenic crown gall cultures of P. quinquefolium.The result shows the PPQ50-2 and PPQ70-2 are both glucans.