新疆红肉苹果多酚的纯化、组成分析与抗氧化活性

本文以新疆红肉苹果为原料,在超声辅助提取红肉苹果多酚的基础上筛选大孔吸附树脂纯化多酚提取物,用高效液相色谱分析纯化后多酚的组成,并以V_C为对照采用体外试验分析其抗氧化活性。结果表明,在5种大孔树脂中NKA-Ⅱ树脂对新疆红肉苹果多酚的吸附和解析效果最好,其静态吸附与解析平衡时间分别为6和10 h;动态吸附和解析试验的最佳纯化工艺为:上样浓度为0.8 mg/mL,上样流速为4.0 BV/h,上样体积为3.5 BV,洗脱液乙醇的浓度为75%;在此条件下,纯化后的新疆红肉苹果多酚的纯度由原来的35%提高至84%。高效液相色谱分析确定纯化后的新疆红肉苹果多酚主要含有10种单酚类物质,其中绿原酸的含量最高(123.15 μg/mL),其次是槲皮苷和原花青素B₂(25.28、21.96 μg/mL)。体外抗氧化试验结果表明,不同浓度多酚对DPPH自由基、羟基自由基、超氧阴离子均具有明显的清除作用,清除率分别达到93.99%(0.1 mg/mL)、99%(0.8 mg/mL)、98%(0.4 mg/mL),并且对脂质过氧化具有明显的保护作用。该试验结果为进一步研究红肉苹果多酚的抗癌活性奠定了基础。

Purification,Composition Analysis and Its Antioxidant Activity of Polyphenols from Red-Flesh Apple of Xinjiang

The red-flesh apple of Xinjiang(Malus niedzwetzkyana Dieck)was used as raw materials in this paper,the red-flesh apple polyphenols was purified through macroporous adsorptive resin method based on the polyphenols extraction with ultrasonic-assisted methodology,and the composition of purified polyphenols from red-flesh apple of Xinjiang was analyzed with HPLC. Using VC as a control,the antioxidant capacity of polyphenols from red-flesh apple in Xinjiang was examined by an antioxidant test in vitro. The results showed that the NKA-II resin behavior of static adsorption and desorption on the polyphenols purification was best in five macroporous resins for red-flesh apple polyphenol,and its absorption and desorption equilibrium time was 6 and 10 h respectively. The optimal process parameters of dynamic adsorption and desorption for apple polyphenols purification were as follows: The concentration of polyphenols and the sampling rate were 0.8 mg/mL and 4.0 BV/h respectively,and the elution concentration and sampling volume were 75% ethanol and 3.5 BV respectively. In this optimal condition,the purity of red-flesh apple polyphenols was increased from 35% to 84%. 10 kinds of phenolic compounds were identified in purified polyphenols by HPLC,which were protocatechuic acid,epigallocatechin,quercitrin,catechinic,procyanidin B2,chlorogenic acid,4-hydroxybenzoic acid,hyperoside,rutin and quercetin. Among them,the contents of chlorogenic acid was the highest with 123.15 μg/mL,followed by quercitrin and proanthocyanidin B2 with 25.28 and 21.96 μg/mL.The results of antioxidant test in vitro showed that the different concentrations of polyphenols from red-flesh apple of Xinjiang had significant free radical-scavenging effect on the DPPH free radical,hydroxyl radicals,superoxide anion,while the clearances ratio were 93.99%(0.1 mg/mL),99%(0.8 mg/mL),and 98%(0.4 mg/mL),respectively. The polyphenols from red-flesh apple of Xinjiang also had obvious protective effect for the lipid peroxidation. This experimental results laid the foundation for further study on the anticancer activity of red-flesh apple polyphenols.