灰树花子实体中水溶性碳水化合物的提取与纯化

灰树花中含有丰富的碳水化合物,本文在不同温度下分别提取灰树花中的低聚糖和多糖,以研究灰树花中水溶性碳水化合物的种类和含量。30 ℃提取低聚糖,浸提液先进行脱盐、脱色处理后,再经Sephadex G-25凝胶过滤得单一物质,核磁鉴定为海藻糖,含量占干重的10.89%。因30 ℃提取后,离心得到的渣相中碳水化合物的含量仍然很高(约30%),为充分利用原料,30 ℃处理后的渣相再用130 ℃高温提取多糖,多糖得率为3.42%(占干重),经Sephadex G-75凝胶过滤分离,得到2种组分,相对分子质量分别为300 kDa和16 kDa。采用扫描电镜观察原料和渣相(130 ℃处理)的表面结构,直观地分析多糖提取后物料表面的微观形态及空间构象的变化,实验结果表明:与原料相比,经高温处理的灰树花残渣呈疏松多孔状,直观反映出可溶性碳水化合物在灰树花中所处位置。

Extraction and Purification of Water-soluble Carbohydrates from the Fruit Body of Grifola frondosa

Grifola frondosa contains abundant carbohydrates. Oligosaccharides and polysaccharides were extracted with different temperatures for the research of the types and contents of water-soluble carbohydrates in G. frondosa. Oligosaccharides were isolated and purified, extracted at a low temperature of 30℃. The structure of oligosaccharide was identified by Nuclear magnetic resonance. A single substance was filtered through the Sephadex G-25 gel after desalting and decoloring. The structural identification results showed that the substance was trehalose with a content of 10.89% (dry weight). The carbohydrate content in the slag phase obtained by centrifugation was still very high (about 30%) after extraction at 30℃. In order to make full use of G. frondosa material, the slag phase, treated by low temperature (30℃), was used to extract polysaccharides at 130℃ and alcohol precipitation, The yield of polysaccharides extracted at high temperature was 3.42% (dry weight), and two polysaccharides were separated by Sephadex G-75 gel filtration, whose relative molecular mass was 300 kDa and 16 kDa, respectively. The surface structure of the raw material and slag (130℃) was observed by scanning electron microscope. The three-dimensional image of the material was obtained quickly and effectively to observe the surface modification of the material. The results showed that compared with the original sample, the residue of G. frondosa treated at high temperature was loose and porous, which reflected the position of soluble carbohydrates in G. frondosa obviously.