紫芝子实体细胞壁多糖的特征分析

Characterization of cell wall polysaccharides from Ganoderma sinense fruit bodies

多糖是紫芝中重要的活性成分,具有抗肿瘤、免疫调节等多种药理作用。为提高紫芝多糖的利用率,以紫芝子实体的水提残渣为原料,经过超微粉碎、热水浸提、分级醇沉(30%、50%、70%),得到紫芝子实体细胞壁粗多糖,并对其得率、多糖含量、单糖组成和分子量分布特征进行了分析。结果表明:紫芝细胞壁粗多糖的总得率为2.0%;分级醇沉后各组分多糖含量在75.33%-98.99%,其中30%乙醇沉淀组分多糖含量最高,为98.99%;各多糖组分主要由葡萄糖组成,另外还含有少量的木糖、甘露糖、半乳糖、葡萄糖醛酸、岩藻糖和葡萄糖胺等;紫芝细胞壁多糖的重均分子量分布为0.8×10~4—135.7×10~4 g/mol。

Polysaccharides,as the important bioactive components in Ganoderma sinense,possess lots of pharmacological effects,such as antitumor and immune regulation.In order to improve the development and utilization of G.sinense,cell wall polysaccharides were extracted from the superfine pulverized powder of hot water extraction residues of G.sinense fruit bodies at 100℃with double-distilled water for two hours.Three polysaccharide fractions,GSCW30 E,GSCW50 E and GSCW70 E,were obtained by stepwise ethanol precipitation with final concentration of 30%,50%and 70%,respectively.The supernatant fraction of 70%ethanol precipitation was coded as GSCW70 EU.The yields,polysaccharide contents,monosaccharide compositions and molecular weight distributions of four fractions were studied.Results showed that the total yield of extracts was 2.0%and the polysaccharide contents of four fractions were between 75.33%and 98.99%.The 30%ethanol extract possessed the highest polysaccharide content with the value of 98.99%.The monosaccharide compositional analysis showed that glucose was the main component in G.sinense cell wall polysaccharides,while some other monosaccharides including xylose,mannose,galactose,glucuronic acid,fucose and glucosamine were also detected in different fractions.The weight average molecular weight of these cell wall polysaccharide fractions ranged from 0.8×10~4 g/mol to 135.7×10~4 g/mol.