中文摘要：

超声提取技术对多糖结构和生物活性的影响具有重要的生物学意义和潜在的应用价值.研究了超声对鸡腿菇多糖结构和生物活性的影响机理.通过HPLC,GC,GC-MS等技术鉴定了热水提取鸡腿菇多糖（WCP3a）和超声波提取鸡腿菇多糖（UCP3a）的一级结构,采用邻苯三酚自氧化法检测了二者的体外抗氧化活性,并对两者一级结构及生物活性的异同进行了比较.结果显示,（1）WCP3a的单糖组成为甘露糖、葡萄糖和半乳糖三种,而UCP3a的单糖组成为甘露糖和葡萄糖两种;（2）WCP3a的糖苷键型为1→4,6甘露糖、1→甘露糖、1→3葡萄糖和1→2,6半乳糖;UCP3a的糖苷键型为1→4,6甘露糖、1→甘露糖、1→3葡萄糖和1→4葡萄糖;（3）WCP3a和UCP3a均能有效清除超氧阴离子,并且UCP3a对超氧阴离子的清除效果更显著;（4）首次发现超声波可引起化学断键及原子重排,导致多糖的组成单位单糖结构发生变化——半乳糖转化为葡萄糖,其转化率随超声功率呈先增大后减小的趋势;随着超声时间的延长,转化率同样呈先增大后减小的趋势.

英文摘要：

The effect of ultrasonic extraction on the structure and biological activity of polysccharides exert important biological significance and potential value.In this paper,the effect mechanism of ultrasonic ex-traction on the structure and biological activity of polysccharides was studied.The chemical structures of WCP3a and UCP3a were analyzed by HPLC,GC,GC/MS and their antioxidant activity in vitro were also measured.The results indicated that（1） The WCP3a was composed of mannose,glucose and galactose,but UCP3a was composed of mannose and glucose;（2） WCP3a contained（1→4,6）-linked-α-D-mannose,（1→）-linked-α-D-mannose,（1→3）-linked-α-D-glucose,and（1→2,6）-linked-α-D-galactose residues,com-paring with UCP3a which containing（1→4,6）-linked-α-D-mannose,（1→）-linked-α-D-mannose,（1→ 3）-linked-α-D-glucose,and（1→4）-linked-α-D-glucose residues;（3） WCP3a and UCP3a can remove the su-peroxide anion effectively,and the antioxidant activity of UCP3a in vitro was higher than that of WCP3a;（4） Galactose,the monosaccharide composition of polysaccharide isolated from Coprinus comatus,was trans-formed to glucose treated by the ultrasound,and the conversion rate first increase and then drop with in-creasing of ultrasound power and treatment time.