梨幼果多酚的纯化及其抗氧化性

Purification and Antioxidant Activity of Polyphenols from Young Pear Fruits

采用5种大孔吸附树脂分离纯化梨幼果多酚,并测定其抗氧化性。结果表明,综合分析吸附与解吸效果,NKA-9大孔树脂性能较好,最适合用来纯化梨幼果多酚;NKA-9大孔树脂对梨幼果多酚进行纯化时,最适宜的条件为:将2 mg/m L的多酚提取液调至p H值为5.0,设定进样流速为1 m L/min,充分吸附,然后用70%的乙醇为洗脱液进行动态洗脱,洗脱流速为1 m L/min,用此方法纯化后的梨幼果多酚的纯度从6.23%提高到30.68%;梨幼果多酚粗品对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl radicals,DPPH)自由基、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate)radicals,ABTS^+·)、亚硝酸基的IC50值分别为:151.07、152.48、490.35μg/m L;梨幼果多酚纯品对DPPH自由基、ABTS^+·、亚硝酸基的IC_(50)值分别为:122.12、130.78、392.09μg/m L;纯化后的多酚样品抗氧化能力比粗品有所增强。

The polyphenols from young pear fruits were purified by5kinds of macroporous adsorption resins,and their antioxidant activity was determined.The results indicated that NKA-9resin had better adsorption and desorption properties than four other resins.Therefore,it was the most suitable resin to purify polyphenols from young pear fruits.The optimum conditions for purification were as follows:after pH adjustment to5.0,the polyphenol at2mg/mL was passed throughthe resin at a flow rate of1mL/min,followed by desorption with70%ethanol at a flow rate of1mL/min.Under these conditions,the purity of the polyphenols from young pear fruits increased from6.23%to30.68%.Both the crude and purified samples had the ability to scavenge1,1-diphenyl-2-picrylhydrazyl(DPPH),2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate)(ABTS)radicals and nitrite,with IC50values of151.07,152.48and490.35mg/mL versus122.12,130.78and392.09mg/mL,respectively.Conclusively,the antioxidant capacity of the purified polyphenols was better than that of the crude sample.