小叶三点金多糖的提取及抗氧化活性研究

Extraction of Polysaccharide from Desmodium microphyllumand Its Antioxidant Activity

【目的】优化小叶三点金(Desmodium microphyllum)多糖的提取工艺,并对它的体外抗氧化活性进行研究。【方法】在单因素实验的基础上,使用响应面法对小叶三点金多糖的提取工艺进行优化,再利用高效液相色谱和红外光谱对它进行单糖组成和表征分析;采用体外ABTS自由基清除实验和还原能力实验对它的抗氧化活性进行检测。【结果】小叶三点金多糖的最佳提取条件是:提取温度为100℃,提取时间为4.86h,料液比为1g∶60mL;该条件下多糖提取率为5.04%±0.14%。小叶三点金多糖由甘露糖、鼠李糖、氨基葡萄糖、葡糖醛酸、葡萄糖、半乳糖和阿拉伯糖组成,摩尔比为5∶4.2∶3∶1∶24.6∶29.6∶9.8。小叶三点金多糖具有较强的还原能力以及ABTS自由基清除能力。【结论】研究结果为小叶三点金多糖的提取及后续应用提供了一定的理论依据。

[Purposes]To optimize the extraction of polysaccharide fromDesmodium microphyllumand investigate its antioxidant and anticancer activities in vitro.[Methods]Based on the analysis of single-factor experiments,response surface methodology was performed to optimize the extraction of polysaccharide from D.microphyllum.The polysaccharide was characterized by using high performance liquid chromatography and infrared spectroscopy.In vitro,the antioxidant activity of the polysaccharide was tested by free radical scavenging and reducing ability experiments,and its anticancer activity was evaluated according to CCK8 kit.[Findings]The results showed that the optimal conditions were as follows:extraction temperature 100℃,extraction time 4.86 h,solid-liquid ratio 1 g∶60 mL.Under these conditions,the experimental yield of D.microphyllumpolysaccharide was 5.04%±0.14%.The polysaccharide was composed of mannose,rhamnose,glucosamine,glucuronic acid,glucose,galactose and arabinose with a molar ratio of 5∶4.2∶3∶1∶24.6∶29.6∶9.8.Meanwhile,in vitro experiments indicated that D.microphyllum polysaccharide exhibited strong radical scavenging activity on ABTS radical as well as reducing ability.[Conclusions]This study provides a theoretical basis for the extraction and subsequent application of D.microphyllumpolysaccharide.