蒜皮水溶性多糖的制备及结构表征

Preparation and Structural Characterization of Water-soluble Polysaccharide from Garlic Skin

为制备蒜皮水溶性多糖(water-soluble polysaccharide from garlic skin,GSWSP)并表征其结构,采用水提醇沉法、DEAE-52纤维素层析法和Sephadex G-100凝胶色谱法,从蒜皮中提取和分离纯化出GSWSP;运用色谱、光谱、扫描电镜观察等方法对其一级结构、高级结构、介观结构进行分析。结果表明:GSWSP的分子质量为2969 Da,由果糖、葡萄糖、半乳糖醛酸、半乳糖、甘露糖、阿拉伯糖和鼠李糖组成,其物质的量比为81.8∶17.6∶15.6∶14.5∶6.5∶4.2∶1,存在→1)-β-D-Fruf-(2→、→1,6)-β-D-Fruf-(2→、→6)-β-D-Fruf-(2→、β-D-Fruf-(2→、α-D-Glc-(1→和β-D-Gal-(1→六种糖残基与β-D-GalA、α-D-Man和α-D-Ara三种基团;溶液中具有三股螺旋高级结构,固体粉末有一定的结晶度;原子力显微镜下GSWSP呈现球形结构,扫描电镜下呈现不规则和破碎的块状结构。综上所述,GSWSP为由蒜皮制备的天然来源的水溶性均一的杂果聚糖多糖,为其在食品、食品配料或添加剂、化妆品等领域中的开发利用提供依据。

A water-soluble polysaccharide from garlic skin(GSWSP)was extracted and purified by sequential water extraction and alcohol precipitation,DEAE-52 cellulose chromatography and Sephadex G-100 gel chromatography,and its primary,spatial,and mesoscopic structure of GSWSP were analyzed using chromatography,spectroscopy,and scanning electron microscopy(SEM).The results showed that the molecular mass of GSWSP was 2969 Da,which was composed of fructose,glucose,galacturonic acid,galactose,mannose,arabinose and rhamnose with a molar ratio of 81.8:17.6:15.6:14.5:6.5:4.2:1.Six sugar residues,→1)-β-D-Fruf-(2→;→1,6)-β-D-Fruf-(2→;→6)-β-D-Fruf-(2→;β-DFruf-(2→;α-D-Glc-(1→;andβ-D-Gal-(1→,and three groups,β-D-GalA,α-D-Man andα-D-Ara,were found in GSWSP.GSWSP exhibited a three-strand helical structure in solution.Its solid powder existed in a crystalline state.Spherical conformation of GSWSP was observed under atomic force microscope,and it showed an irregular broken lumpy structure as observed under SEM.In summary,GSWSP can be used as a homogeneous polyfructan in foods and cosmetics.