黑木耳多糖的磷酸化修饰及其抗氧化活性研究

本研究对黑木耳胞外多糖(Auricularia auricular polysaccharide,AAP)进行磷酸化修饰,通过响应面法优化了磷酸化修饰黑木耳多糖的工艺条件,并对磷酸化黑木耳多糖(phosphorylated auricularia auricula polysaccharide,P-AAP)进行抗氧化活性研究。结果显示磷酸化修饰黑木耳多糖的最佳条件为磷酸化试剂中三聚磷酸钠(sodium tripolyphosphate,STPP)与三偏磷酸钠(sodium trimetaphosphate,STMP)质量比为5:2,反应温度88℃,反应时间5 h,反应pH为8.6,此条件下多糖中磷酸根含量为9.93%。抗氧化活性试验结果表明,与AAP相比,经过DEAE-Sepharose Fast Flow柱及葡聚糖凝胶G-100柱纯化后的P-AAP1对DPPH自由基的清除率提高了34.37%,半抑制浓度(IC₅₀)为1.07 mg/mL;对羟基自由基的清除率提高了30.39%,IC₅₀值为0.91 mg/mL;对超氧阴离子自由基的清除率提高了26.40%,IC₅₀值为0.41 mg/mL。因此,黑木耳胞外多糖通过磷酸化修饰后其抗氧化活性能被显著提高。

Study on the Phosphorylation Modification and Antioxidant Activity of Polysaccharides of Auricularia auricular

In this study,phosphorylation modification of Auricularia auricular polysaccharide(AAP)was explored. The conditions for the phosphorylation of Auricularia auricula polysaccharide were optimized by response surface methodology. At the same time,the antioxidant activity for phosphorylated Auricularia auricula polysaccharide(P-AAP)was still explored. The results showed that the optimal conditions for the phosphorylation of Auricularia auricular polysaccharide were the mass ratio of sodium tripolyphosphate(STPP)to sodium trimetaphosphate(STMP)in phosphorylation reagent was 5:2,the temperature 88℃,pH was 8.6 and time was 5 h. Under these conditions,the content of phosphate in polysaccharides was 9.93%.In addition,P-AAP1 were obtained through DEAE-Sepharose Fast Flow and Sephadex G-100 chromatography. And the results of antioxidant activity showed that the DPPH radical scavenging rate of P-AAP1 increased by 34.37% compared with AAP,the half inhibitory concentration(IC₅₀)was 1.07 mg/mL. And the scavenging rate of hydroxyl radical increased by 30.39% compared with AAP,the IC₅₀ was 0.91 mg/mL. The scavenging rate of superoxide anion radicals increased by 26.40% compared with AAP,and the IC₅₀ was 0.41 mg/mL. In conclution,the antioxidant activity of Auricularia auricular polysaccharide can be improved by phosphorylation modification.