超声波提取对麦冬多糖结构和抗氧化活性的影响

Effect of the Ultrasonic Extraction on the Structure and Antioxidant Activity of Polysaccharide from Ophiopogon Japonicus

研究了超声波提取法在提取麦冬多糖过程中,对麦冬多糖的结构和抗氧化活性的影响。利用气相色谱法、环境扫描电子显微镜、原子力显微镜对其进行初步结构分析,然后在体外化学模拟条件下,测定它的总还原能力、对羟基自由基的清除作用及对Fe2+诱发的脂质过氧化反应的抑制作用,并与传统热水提取法提取得到的麦冬多糖进行对比。超声波提取得到的麦冬多糖(SBP)和传统热水提取法提取得到的麦冬多糖(WBP)具有相同的单糖组成,都包括阿拉伯糖、甘露糖、葡萄糖及半乳糖,环境扫描电子显微镜的结果显示经超声提取的多糖的片状结构有不同程度的变小;原子力显微镜的扫描分析显示超声波使其糖链的分子片断变小,且SBP的抗氧化活性都要高于WBP。经超声波处理不会影响多糖的单糖组成,但会改变多糖的微观结构同时提高多糖的抗氧化活性。

The effect of the ultrasonic extraction on the structure and biological activity of polysaccharide from Ophiopogon japonicus has been studied in this work.Its chemical structure was analyzed by the techniques of gas chromatography,scanning electron microscopy and atomic force microscopy（AFM）.The total reducing power,scavenging effect on hydroxyl radical（·OH） and inhibiting effect on lip id-peroxidation induced by Fe^2＋ of Ophiopogon japonicus polysaccharide were measured in vitro chemical simulated systems for evaluating its antioxidant activity.Comparing with the Ophiopogon japonicus polysaccharide（WBP） obtained by the conventional hot water extraction method,the Ophiopogon japonicus polysaccharide（SBP） obtained by the ultrasonic extraction has the same monosaccharide components,in which include the arabinose,glucose and galactose.The scanning electron microscopy in vitro showed that the sheet structure of the polysaccharide obtained by the ultrasonic extraction method was become small to varying degrees;while the atomic force microscopy（AFM） showed that the molecular fragment of the Ophiopogon japonicus polysaccharide chains was become small by the ultrasonic.The antioxidant activity of SBP is better than that of WBP at the same concentration.The ultrasonic extraction can not affect the monosaccharide components of the polysaccharide,but the micro-structure of the polysaccharide can be altered and the antioxidant activity of the polysaccharide can be increased.