毛薯多糖提取分离工艺优化及抗氧化活性研究

Extraction,Isolation,Process optimization and Anti-oxidant Activity of Polysaccharides from Dioscorea esculenta

毛薯是海南的传统杂粮,富含植物多糖。本研究以毛薯块茎粉末为材料探究毛薯多糖的提取工艺和抗氧化活性。采用热水提取法分别进行单因素和三因素三水平L_(9)(3^(3))正交实验,优化毛薯多糖提取工艺。毛薯粗多糖溶液经Sveag法除蛋白、透析、DEAE-52纤维素柱和SephadexG-100凝胶柱层析分离纯化得到毛薯精多糖。采用DPPH法、羟自由基法、超氧阴离子法和还原法检测毛薯多糖的抗氧化活性。结果表明:热水提取法最佳工艺条件为温度70℃、料液比1∶15、提取时间3 h,毛薯多糖提取率为1.94%;毛薯多糖经过多次分离纯化后,得到纯度均一的中性多糖;毛薯精多糖DPPH自由基清除能力较弱,1~5 mg/mL的清除率保持在10%左右,且随着多糖浓度的升高,清除能力逐渐下降;毛薯精多糖羟自由基活性随着多糖浓度的升高,活性逐渐增加,在5 mg/mL时清除率最高达到34.74%;毛薯精多糖超阴氧离子自由基活性随着多糖浓度的升高,活性逐渐降低,在1 mg/mL时清除率最高达67.35%;毛薯精多糖还原能力较弱,1~5 mg/mL的还原力最高为0.17。该研究优化了毛薯多糖的提取工艺,毛薯多糖具有一定的抗氧化活性,为后续毛薯功能性产品的开发和药物功能机理的研究奠定基础。

Dioscorea esculenta(Lour.)brukill is a traditional miscellaneous grain in Hainan,and it is rich in polysac-charides.This study investigated the extraction process and anti-oxidant activity of the polysaccharides from D.escu-lenta by using the D.esculenta tuber powder as the raw material.The hot water extraction was used to optimize the extraction process of polysaccharides from D.esculenta by single factor experiments and three-factor and three-level L_(9)(3^(3))orthogonal tests.The crude polysaccharides from D.esculenta were purified by the Sveag method,dialysis,DEAE-52 cellulose column and SephadexG-100 gel column chromatography.The anti-oxidant activity of polysaccha-ride from D.esculenta was detected by DPPH method,hydroxyl radical method,superoxide anion method and reduction method.The optimal extraction method of the hot water extraction included temperature 70℃,solid-liquid ratio 1∶15,and extraction time 3 h.The polysaccharides extraction rate of D.esculenta was 1.94%.After multipleseparation and purification,neutral polysaccharides with uniform purity were obtained.The expriments of anti-oxidant activity of polysaccharides from D.esculenta showed that the DPPH radical scavenging capacity of polysaccharide from D.escu-lenta was weak.The polysaccharide from D.esculenta and scavenging rate of 1-5 mg/mL was maintained at about 10%,and with the increase of polysaccharide concentration,the scavenging capacity gradually decreased.The hydroxyl radi-cal activity increased with the increase of polysaccharide concentration,and the scavenging rate reached 34.74%at 5 mg/mL.The superoxide anion free radical activity decreased gradually with the increase of polysaccharide concentra-tion,and the scavenging rate reached 67.35%at 1 mg/mL.The reduction capacity of polysaccharides was weak,and the reduction capacity of 1-5 mg/mL remained 0.17.In this study,the extraction process of polysaccharides from D.escu-lenta was optimized,and it had certain antioxidant activity.It would lay the foundation for the functional product de-velopment and the mechanism research of drug function of D.esculenta.