皱皮木瓜多糖的分离、纯化及抗氧化活性研究

为了研究木瓜多糖的提取、分离、纯化与抗氧化活性,采用水提醇沉法提取皱皮木瓜中的多糖,得多糖Ⅰ;利用Sevag法除去多糖中的蛋白质后得多糖Ⅱ;以30%H_2O_2脱除色素后再次醇沉得到精制多糖Ⅲ;透析除去小分子后利用AB-8大孔树脂进行分离以水、30%、50%、70%和95%乙醇洗脱,其中水洗脱部分多糖为Ⅳ。用苯酚-硫酸法测定多糖含量。多糖Ⅰ得率为9.83%,多糖含量(纯度,下同)为64.45%;脱蛋白后多糖Ⅱ中多糖含量为78.23%;经脱色后多糖Ⅲ含量达88.39%;大孔树脂水洗脱部分多糖Ⅳ含量为89.74%。以DPPH(2,2-二苯基-1-苦肼基)清除率和Fe~(3+)还原力方法测定木瓜多糖的抗氧化活性,木瓜多糖均体现出一定的抗氧化作用,呈浓度依赖性增强,其中多糖Ⅰ、Ⅱ表现出更好的作用。

Isolation,purification, and antioxidant activity of polysaccharides from Chaenomeles speciosa Nakai

This paper is aimed to study the extraction,separation,purification,and antioxidant capacity of polysaccharides from Chaenomeles speciosa.Polysaccharide Ⅰ was obtained by water extraction and alcohol precipitation with the yield of 9.83 ％.Then,proteins were removed by using Sevag method to obtain polysaccharide Ⅱ.Further ly,30％ H2O2 was used to remove the pigments to get more refined polysaccharide Ⅲ.AB8 macroporous resin was used to obtain the water,30％,50％,70％,95％ ethanol eluting fraction,of which the water fraction was named as polysaccharide Ⅳ.The contents of polysaccharides Ⅰ,Ⅱ,Ⅲ and Ⅳ were determined as 64.45％,78.23％,88.39％ and 89.74％,respectively.It was found that these polysaccharides showed antioxidant activities by DPPH (2,2-diphenyl-1-picrylhydrazyl) clearance and Fe3+ reducing power assays,and polysaccharides Ⅰ and Ⅱ showed better an tioxidant activity.