滑菇多糖wPNP-a1的制备及结构分析

Preparation and Structural Characterization of wPNP-a1 from Pholiota nameko

利用传统热水浸提法提取滑菇粗多糖(wPNP),进而用季铵盐沉淀法和Sephadex G-150凝胶色谱柱层析对wPNP进行纯化,得滑菇多糖wPNP-a1。以高效液相色谱(HPLC)、傅里叶变换红外光谱(FTIR)、气相色谱(GC)、核磁共振(NMR)、环境扫描电子显微镜(ESEM)和原子力显微镜(AMF)等方法分析wPNP-a1的结构,结果表明,滑菇多糖wPNP-a1的分子量为419310 Da,具有一般类多糖的特征吸收峰,糖苷键为β-型,不含乙酰基,由木糖、甘露糖、半乳糖和葡萄糖组成,其摩尔比为3.91∶2.77∶1.91∶1;wPNP-a1的分子间排斥力较大,分子间吸引力较小,在云母表面呈直链状分布,链宽23 nm左右,链高0.7～0.8 nm。

Water-soluble crude polysaccharide （wPNP） was extracted from cultured mycelium of the fungus Pholiota nameko by hot water extraction. The extraction rates of polysaccharide were 2. 463%. The content of total polysaccharide was determined by the phenol-sulphuric acid method,and the value was 64.98%. The crude polysaccharides were purified by CTAB and Sephadex-150 in sequence,with the obtained one designated as wPNP-al. The structure of wPNP-al was analysed by HPLC, FTIR, GC, NMR, ESEM, and AFM. The results showed that the average molecular weight of wPNP-al was 419310 Da. It had the general characteristics of polysaccharide absorption peaks,β-glycoside linkage, and no acetyl. The GC analysis indicated wPNP-al was composed of xylose, mannose, galactose, and glucose in molar ratios of 3.91：2.77：1.91：1. The repelling forces between the molecules were stronger than the attractive forces. The wPNP-al formed a linear chain on the surface of mica,the width was 23 nm, and the height was 0.7-0.8 nm.