分心木酸性多糖SJP-2的理化性质及其抗氧化活性研究

Physicochemical properties and antioxidant activity of acid polysaccharide sjp-2 from Semen Juglandis

以分心木为原料进行热水浸提,经过醇沉、脱色素、脱蛋白以及DEAE-Sepharose Fast Flow离子交换柱色谱和Sephadex-G50凝胶柱色谱分离纯化得到一种酸性多糖组分（SJP-2）,再对该组分进行理化性质及抗氧化活性分析。结果表明：SJP-2不含蛋白,是一个低分散度,分子量较为均一的多糖,分子量为3.239×10^3g/mol;HPLC分析得知SJP-2为一种酸性多糖,其单糖组成及摩尔比例为阿拉伯糖∶半乳糖∶葡萄糖∶半乳糖醛酸=1∶2.62∶4.45∶18.53;抗氧化活性测得SJP-2清除DPPH自由基、羟自由基以及ABTS自由基的IC50分别为0.094、0.945、0.591 mg/m L,还原能力在1.0 mg/m L时达到1.158,ORAC值为（1217.99±31.22）μmol TE/g,说明SJP-2具有较高的体外抗氧化能力。

The polysaccharide SJP-2 from Semen Juglandis was obtained by hot water extraction and alcohol precipitation, and purified using DEAE-Sepharose Fast Flow chromatography and Sephadex-G50 gel column chromatography.The physicochemical properties and antioxidant activity of SJP-2 were determined.The result showed that SJP-2 without proteins, was a lower dispersion polysaccharide with uniform molecular of 3.239×10^3g/mol, and the purity was 99.61%.The SJP-2 was acid polysaccharide determined by HPLC,and composed of arabinose,galactose,glucose, and galacturonic acid with a molar ratio of 1： 2.62： 4.45： 18.53.The IC50 of DPPH scavenging activity, hydroxyl radical scavenging activity, and ABTS scavenging activity were 0.094, 0.945, 0.591 mg/mL,respectively.At 1 mg/mL, the reducing power was 1.158. The ORAC of SJP-2 was （ 1217.99±31.22） μmol TE/g.lt was demonstrated that SJP-2 had higher antioxidant activity.