超声波处理对柴胡多糖提取率、微观形貌特征及生物活性的影响

为了研究超声波辅助提取柴胡多糖的过程中超声波对柴胡多糖的提取率及外观形貌、生物活性的影响，在单因素（超声波功率、超声波作用时间、料液比）的基础上，通过正交实验确定超声波辅助提取最佳工艺条件，并与传统提取方法所得到的结果进行了比较：利用原子力显微镜（AFM）研究超声波作用对柴胡多糖的形貌特征的影响；用邻二氮菲-金属铁离子-H2O2体系检测柴胡多糖对羟基自由基的清除作用。实验结果表明：超声波辅助提取的最佳提取条件为超声功率360W，超声时间15min，料液比1：35，水浴温度90℃，水浴时间1h，提取率为2．58％．所获得的柴胡多糖（SBR）的纯度为44．14％，与传统提取方法相比．不仅节约了时间，而且提高了提取效率。原子力显微镜观察的结果表明，柴胡多糖分子主要以螺旋结构形态存在，超声波作用使得柴胡多糖的分子降解成较小的分子片段。柴胡多糖能有效清除羟自由基，在相同浓度下SBP。的清除效果要优于水提柴胡粗多糖（WBP0），且质量浓度在80～100ug／mL的范围清除效果最佳，并高于同浓度下抗坏血酸的清除效果。

Effect of ultrasound on extraction yields,morphology,and biological activity of polysaccharide from Bulpeurum

To study the effect of ultrasound on extraction yields and morphology of polysaecharides from Bulpeurum,single factor tests and orthogonal test were imployed to optimize the extraction process conditions of ultrasound-assisted and the traditional methods. Atomic force microscope （AFM） was used to characterize the morphology of the polysaccharides extracted in the untrasound-assisted process （SBP0） and the polysaccharides extracted by traditional method （WBP0 ）. The phenanthroline-Fe^2＋ reaction system was used to estimate the activity of Bulpeurum polysacchafide against hydroxyl radicals. The best conditions of ultrasound-assisted extraction were shown as follows： ultrasonic power of 360 W for 15 rain, feed to liquid ratio at 1 ： 35,temperature at 90 ℃ for 1 h. The extraction yield reached 2.58% and the the purity was 44.14%. AFM images showed that the Bupleurum polysaccharides mainly existed in spiral form. Ultrasonic degradation diminished the linear scale of the Bupleurum polysaccharide molecular chains. The scavenging activity against hydroxyl radicals in vitro was positive. The activity of SBP0 was better than that of WBP0 at the same concentration. Within concentration of 80 to 100 ug/mL, the olysaccharide exhibited higher acitivity than that of ascorbic acid.