白簕多糖的分离纯化及抗氧化活性研究

目的提取、分离和纯化白簕多糖(ATP),测定单糖组成和相对分子质量(M)分布,并进行体外抗氧化活性检测。方法通过水提醇沉、Sevage法、DEAE-cellulose 52和Sephadex G-50柱色谱法分离、纯化ATP。采用HPLC和高校凝胶渗透色谱(HPGPC)法对多糖的单糖组成和相对分子质量分布进行测定。通过体外清除DPPH·、ABTS~+·、羟基自由基(·OH)和超氧阴离子(O_2~-·)自由基的方法,评价ATP的抗氧化活性。结果获得1个量较高的中性均一多糖(ATP1-1)以及2个酸性多糖组分ATP2、ATP3。ATP1-1主要由葡萄糖和少量半乳糖、甘露糖、鼠李糖组成。ATP2主要由葡萄糖醛酸、葡萄糖、半乳糖、阿拉伯糖和少量甘露糖、鼠李糖组成。ATP3主要由鼠李糖、葡萄糖醛酸、葡萄糖、半乳糖和阿拉伯糖组成。ATP1-1的重均相对分子质量(Mw)为2 310。抗氧化实验表明ATP1-1对DPPH·、ABTS~+·、·OH和O_2~-·自由基均有明显的清除作用,半数抑制浓度(IC_(50))分别为0.042 4、0.007 9、2.313 6、1.753 0 mg/m L。结论 ATP1-1有较好的抗氧化活性并呈现出良好的量效关系。

Isolation, purification and anti-oxidant activity of polysaccharides from Acanthopanax trifoliatus

Objective To extract, isolate and purify the polysaccharides from Acanthopanax trifoliatus (ATP), determine the monosaccharide composition and molecular weight distribution of ATP, and evaluate its anti-oxidant activity in vitro. Methods ATPs were prepared by water extraction ethanol precipitation. Sevage deproteinization, DEAE-cellulose 52, and Sephadex G-50 column chromatography were applied for the further isolation and purification of polysaccharides. Then, the monosaccharide composition and mean molecular mass of ATP were analyzed by HPLC and HPGPC. The antioxidant activity of ATP was evaluated through the scavenging capabilities of DPPH·, ABTS⁺·,·OH and O₂^· free radicals. Results A neutral homogeneous polysaccharide (ATP1-1) and two acidic polysaccharides (ATP2 and ATP3) were obtained by column chromatography. According to the HPLC analysis, ATP1-1 consists of glucose, galactose, mannose and rhamnose. ATP2 consists of glucuronic acid, glucose, galactose, arabinose, mannose, and rhamnose. ATP3 was composed of rhamnose, glucuronic acid, glucose, galactose, and arabinose. ATP1-1 with the average molecular mass of 2 310, had obvious effect on scavenging ability of DPPH·, ABTS⁺·,·OH and O₂^· free radicals, with IC₅₀ values of 0.042 4, 0.007 9, 2.313 6, and 1.753 0 mg/mL, respectively. Conclusion ATP1-1 displayed obvious anti-oxidant activity with a good dose-effect relationship.