中文摘要：

本文利用热水提取法与超声提取法提取麦冬多糖,并利用傅里叶变换红外光谱法、原子力显微镜（AFM）及扫描电子显微镜（SEM）对两种方法提取的麦冬多糖的官能团及表面形貌进行了比较研究。结果表明,热水提取的麦冬多糖（WPOJ-DS）与超声提取的麦冬多糖（UPOJ-DS）的官能团存在明显差别,在WPOJ-DS中检测到β-葡萄吡喃糖,而UPOJ-DS中没有。两种多糖的AFM观测结果表明,相对于WPOJ-DS,UPOJ-DS的分散性更好,能观察到多糖单分子链形态以及明显的螺旋结构,说明超声处理可能对麦冬多糖的分子间及分子内氢键产生影响。SEM结果表明,UPOJ-DS相对于WPOJ-DS大片状结构减少,且出现很多棒状及小球状颗粒,说明超声处理使麦冬多糖产生了降解。因此,超声提取法会对麦冬多糖的分子结构及聚集行为产生影响。

英文摘要：

In this paper,different extraction methods including hot water and ultrasound were used to extract polysaccharides in ophiopogon japonicus.The functional group distribution and surface morphology of polysaccharides extracted by the two methods were studied by FT-IR spectroscopy,atomic force microscopy（AFM） and scanning electron microscopy（SEM）.The results showed that the difference of functional group between ophiopogon japonicus polysaccharides extracted by hot water（WPOJ-DS） and ultrasound（UPOJ-DS） was obvious.β-glucopyranoside was detected in WPOJ-DS using infrared spectroscopy,but not in UPOJ-DS.The results of AFM showed that the dispersion of UPOJ-DS was significantly higher than that of WPOJ-DS.Single molecule chain and helical structure were observed in UPOJ-DS by AFM,indicating that intermolecular and intramolecular hydrogen bonds of polysaccharides were affected by ultrasound.The results of SEM showed that less of bigger schistose structures were observed in UPOJ-DS compared to WPOJ-DS,and a lot of rod-shaped and small globular aggregates were observed in UPOJ-DS,indicating that supersonic treatment created degradation on ophiopogon japonicus polysaccharides.Therefore,ultrasonic extraction has an effect on molecular structure and aggregation behavior of ophiopogon japonicus polysaccharides.