白背毛木耳多糖APP3a磷酸化修饰工艺及其抗氧化活性

Phosphorylation Modification Process of a Novel Polysaccharide APP3a from Auricularia polytricha and Its Antioxidant Activity

以白背毛木耳为原料,采用热水浸提法提取白背毛木耳多糖(polysaccharides from Auricularia polytricha,APP),通过离子交换柱层析和凝胶柱层析对APP进行纯化,得到1个单一组分APP3a,以磷酸根含量为指标,探讨磷酸化试剂比例、反应温度、时间、p H对APP3a磷酸化修饰的影响,在单因素试验基础上,采用响应面Box-Behnken试验设计优化APP3a磷酸化修饰工艺,并通过对羟基自由基、超氧阴离子自由基和DPPH自由基的清除作用研究APP3a磷酸化前后抗氧化活性。结果表明, APP3a磷酸化修饰工艺为磷酸化试剂比例3︰4、反应温度50℃、反应时间5 h、pH 9,在最佳工艺条件下,磷酸根含量为7.41%。抗氧化试验研究表明,与APP3a相比,磷酸化APP3a对羟基自由基、超氧阴离子自由基清除能力增强,对DPPH自由基的清除能力有所减弱。

Auricularia polytricha was used as raw materials,and the polysaccharides from A.polytricha(APP) were extracted by hot water extraction.The APP was purified by ion exchange column chromatography and gel column chromatography to obtain a novel polysaccharide coded APP3 a.The phosphate content was used as an indicator to explore effect of phosphorylation reagent ratio,reaction temperature,time,and pH on APP3 a phosphorylation.Based on single factor experiments,the response surface Box-Behnken test design was used to optimize APP3 a phosphorylation.Antioxidant activity of APP3 a before and after phosphorylation was tested by scavenging hydroxyl radicals,superoxide anion radicals and DPPH radicals.The results showed that the optimal APP3 a phosphorylation modification process was phosphorylation reagent ratio of 3︰4,reaction temperature of 50 ℃,reaction time of 5 h and pH of 9.Under the optimal process condition,the phosphate content was 7.41%.Compared with APP3 a,phosphorylated APP3 a had stronger scavenging ability of hydroxyl free radicals and superoxide anion free radicals.The scavenging ability of DPPH free radicals weakened in a degree.