双水相法分离黑穗醋栗果实多糖及其结构和活性研究

Isolation of Polysaccharides from Black Currant Fruit by Aqueous Two Phase System and It's Structure and Activities

本文探讨了双水相体系分离黑穗醋栗果实多糖的最优条件,采用红外光谱、气相色谱及高效液相色谱对分离得到的黑穗醋栗果实多糖(BCP)的结构进行初步表征;测定黑穗醋栗果实多糖清除自由基(DPPH·、·OH和O_2^-·)的活性及总还原能力。结果表明,双水相体系分离黑穗醋栗果实多糖最佳条件是:曲拉通X-114质量浓度0.6 mg/mL、温度50℃、pH 3.5、氯化钠浓度0.003 mol/mL。在此条件下,黑穗醋栗果实多糖的回收率为(94.22±1.22)%,蛋白的清除率为(95.36±1.16)%,多糖的纯度达(90.13±0.002)%,与分离前相比高出1.59倍。BCP的分子质量为1.52×10~4 ku,单糖组成及物质量比为鼠李糖∶阿拉伯糖∶木糖∶甘露糖∶葡萄糖∶半乳糖=1.7∶6.6∶1.3∶1.1∶0.6∶4.8。红外光谱结果显示:其含有多糖的特征吸收峰,并可能含有α-糖苷键及吡喃糖环;黑穗醋栗多糖对自由基有一定的清除作用和还原能力,且抗氧化能力和还原能力随浓度的增加而增强,呈量效关系。

This paper discussed the optimal isolation conditions of the aqueous two-phase system for polysaccharides from black currant.The basic structure and composition analysis of BCP were identified by using infrared spectroscopy,gas chromatography and high performance liquid chromatography.In addition,the antioxidant activity of BCP was investigated by measuring its scavenging ability on DPPH,hydroxyl radicals,superoxide radical and reducing power.The results indicated the optimal extraction conditions for the polysaccharides from black currant were determined as follows,Triton X-114 0.6 mg/mL,temperature 50 ℃,pH 3.5,NaCl 0.003 mol/mL.The highest recovery yield of BCP was（94.22±1.22）% and the removal rate of protein was（95.36±1.16）%.Its purity was up to（90.13±0.002）%,which was 1.59 multiple higher than before.The average molecular weight of BCP was measured to be 1.52×10^4ku,and Gas chromatography analysis indicated that BCP was comprised of rhamnose,arabinose,xylose,mannose,glucose,galactose with molar ratio of 1.7∶6.6∶1.3∶1.1∶0.6∶4.8.Characteristic absorption peaks of BCP were shown in IR spectrum and BCP might have α-pyranose and pyran ring.The antioxidant activities and reducing power of polysaccharides increased with the increase of concentration,in a concentration effect manner.