皱皮木瓜多糖的分离、纯化及抗氧化活性研究

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

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。

This paper is aimed to study the extraction, separation, purification, and antioxidant capacity of poly- saccharides 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 H. Further- ly, 30%H2O2 was used to remove the pigments to get more refined polysaccharide [1I. AB-8 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 polysaccharidesⅠ, 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-di- phenyl-l-picrylhydrazyl） clearance and Fea＋ reducing power assays, and polysaccharides I and Ⅱ showed better an- tioxidant activity.