超声提取功率对麦冬多糖结构及抗氧化活性的影响

The effect of ultrasonic power on the structure and antioxidant activity of ophiopogon japonicus polysaccharides

为了揭示超声功率对麦冬多糖结构及活性影响的规律,选用5种功率超声提取麦冬多糖,并利用季铵盐沉淀法对其进行分离,分别得到了5种AP1和AP3多糖.然后利用高效液相色谱法和气相色谱法分别对AP1和AP3多糖的分子量分布、单糖组成进行了分析研究.结果表明:起初随着超声功率的增大,不断有较大分子量的多糖被提取,但随着超声功率的进一步增大,大分子量的多糖分子量减半,被降解为较小分子量的多糖.气相色谱研究表明随着超声提取功率的不断增大,嵌入麦冬原材料中较稳定,利用小功率很难被提取出来单糖组分如鼠李糖、阿拉伯糖和木糖均被提取.AP1和AP3多糖的抗氧化活性结果表明:随着超声功率的增大,麦冬多糖的抗氧化活性呈现出先增大后减小的趋势,且超声功率为400W时其抗氧化活性最高.可见,超声功率对麦冬多糖的结构及活性均有显著影响.

The purpose of our study is to reveal the influence rule of ultrasonic power on the structure and activity of ophiopogon japonicus polysaccharides. Five kinds of ultrasonic power are selected to extract polysaccharides from ophiopogon japonicus root. Precipitation by quaternary ammonium salt was applied to isolate the five kinds of polysaccharides extracted by ultrasound respectively. The polysaccharides of AP1 and AP3 were obtained. Then high performance liquid chromatography and gas chromatography was applied to detect molecular weight distribution and monosaccharide composition of five kinds of polysaccharide AP1 and AP3. Our results show that： as the ultrasonic power increasing larger molecular weight polysaccharides were obtained, however with the further increase of ultrasonic power a large number of high molecular weight polysaccharides are degraded into small molecular weight polysaecharide, and this phenomenon is mainly induced by large molecular weight polysaccharide molecular weight cutting in half. Gas chromatography studies show that： with small ultrosonic power it is a hard work to extract monosaccharide components which are steadily embedded in ophiopogon japonicus raw material. However with the increase of ultrosonic power rhamnose, arabinose and are extracted. Antioxidant activity shows that increasing the ultrasonic power, antioxidant activity of ophiopogon japonicus polysaccharide increased to the maximum and then decreased. The antioxidant activity was highest when the ultrasonic power was 400W. Therefore, ultrasonic power on the structure and activity of ophiopogon japonicus polysaccharide has significant influence.