紫苏叶多糖分离纯化及体外抗氧化活性

Separation and Purification of Perilla frutescens Polysaccharides and Their Antioxidant Activities in vitro

通过水提醇沉法得到紫苏叶粗多糖(Perilla frutescens leaf polysaccharides,PFP),并用DEAE-52纤维素层析法对其进行分离纯化,获得4个多糖组分PFP-1、PFP-2、PFP-3和PFP-4。PFP-1为中性低聚糖,但总糖含量较低;PFP-2重均分子量为4.7 kDa,峰位分子量为2.2 kDa,主要组成单糖为半乳糖醛酸;PFP-3主要由两种分子量段的多糖组成,主要峰位分子量为5.2 kDa和40.0 kDa,为杂多糖,所含单糖种类较多,主要含半乳糖醛酸和半乳糖;PFP-4分子量较小,主要组成单糖为半乳糖和阿拉伯糖。体外抗氧化活性试验表明,PFP的DPPH自由基清除能力、ABTS+自由基清除活性和Fe3+还原能力较强,具有良好的抗氧化活性,其中组分PFP-3和PFP-4抗氧化活性与PFP接近,是其发挥抗氧化作用的关键组分。

Perilla frutescens polysaccharides(PFP)were obtained by water extraction and alcohol precipitation.Then they were isolated and purified by DEAE-52 cellulose chromatography,and a total of four polysaccharide components PFP-1,PFP-2,PFP-3 and PFP-4 were obtained.PFP-1 was a neutral oligosaccharide,but the total sugar content was lower.PFP-2 had a molecular weight of 4.7 kDa while the peak molecular weight was 2.2 kDa,and the main monosaccharide was galacturonic acid.PFP-3 was mainly composed of two molecular weight segments of polysaccharides,with the main peak molecular weights of 5.2 kDa and 40.0 kDa,and was a heteropolysaccharide,containing many kinds of monosaccharides,mainly galacturonic acid and galactose.PFP-4 had a low molecular weight,and its main monosaccharide components were galactose and arabinose.In vitro antioxidant activity test showed that PFP had strong DPPH radical scavenging activity,ABTS+radical scavenging activity and Fe3+reduction ability,and had good antioxidant activities.The antioxidant activities of components PFP-3 and PFP-4 were close to those of PFP,and they were the key components to play its antioxidant role.