不同分子量条斑紫菜多糖体外抗氧化活性研究

Study on antioxidant activity of polysaccharides with different molecular weights from Pyropia yezoensis in vitro

摘要:

采用4种不同截留分子量(MWCO)的超滤膜对条斑紫菜多糖(Pyropia yezoensis Polysaccharide,PP)进行分离,得到分子量分别为PPⅠ(MW≥100 000)、PPⅡ(MW:50 000-100 000)、PPⅢ(MW:10 000-50 000)、PPⅣ(MW:5 000-10 000)和PPⅤ(MW≤5 000)5种不同分子量的多糖,进一步对5种多糖进行体外抗氧化活性研究。结果表明,在实验浓度范围内,不同分子量的PP都具有较强的抗氧化能力,对羟自由基(·OH)、超氧阴离子(·O₂^-)、DPPH·自由基都具有较好的清除作用,自由基清除率均随多糖浓度的增加而增大,呈现量效关系;抗氧化能力与其相对分子质量大小相关,分子量较小的PPⅤ(MW ≤ 5 000)抗氧化能力最佳,明显高于分子量较大的PPⅠ(MW≥100 000)。超滤能够实现不同分子量PP的良好分离,可作为条斑紫菜多糖活性成分开发利用的一种新方法。总多糖中,MW在5 000以下的PP为主要功效成分,开发利用价值较大。

Abstract:

In this research,polysaccharides from Pyropia yezoensis were separated by four ultrafitration membranes in different molecular weight cut-off(MWCO) to obtain five parts of relative molecular weight :PPⅠ(MW≥100 000), PPⅡ(MW:50 000-100 000), PPⅢ(MW:10 000-50 000), PPⅣ(MW:5 000-10 000) and PPⅤ(MW≤5 000),for further study,the antioxidant activity of PP with different molecular weights was determined. The results showed that PP with different molecular weights all have antioxidant capacity in the experimental concentration range of PP,they all have good hydroxyl radical(·OH) scavenging activity, superoxide anion(·O₂^-) radical scavenging effects and DPPH radical scavenging activity, and scavenging rate increased with increasing concentration of polysaccharides, showing a dose-effect relationship; antioxidant activity was related to the size of its relative molecular weight, and the antioxidant activity of small molecular polysaccharide PPⅤ(MW≤ 5 000) was best, significantly higher than the greater molecular weight PPⅠ(MW≥100 000). Ultrafiltration technology could achieve good separation of PP, it could be used as a new method for the development and utilization of the active component from Pyropia yezoensis, and the PP of MW below 5 000 was the main active component and worthy of exploitation in future.