两种单丛茶多糖的表征及体外抗氧化活性研究

Characterization and in vitro antioxidant activity study of two polysaccharides from Dancong Tea

中文关键词:  单丛茶  多糖  表征  体外抗氧化活性

英文关键词:Dancong tea  polysaccharides  characterization  in vitro antioxidant activity

中文摘要:

      目的 对单丛茶中提取分离得到的两种多糖(分别为TPS-40、TPS-80)进行表征, 并研究其体外抗氧化活性。方法 通过离子交换柱层析、葡聚糖凝胶柱层析、傅里叶变换红外光谱分析、扫描电子显微镜和X射线衍射光谱分析对两种多糖进行初步表征; 测定两种多糖对2,2-联苯基-1-苦基肼基(2,2-diphenyl-1-picrylhydrazyl, DPPH)自由基、羟基自由基的清除能力以及铁离子还原能力, 评价它们的体外抗氧化活性。结果 TPS-40、TPS-80的糖醛酸占比分别为(54.25±0.25)%、(46.39±0.39)%, 说明它们均为酸性多糖。DEAE-52柱层析、葡聚糖凝胶柱层析中两种多糖都洗脱出一个主峰, 说明它们的组分都较为集中。TPS-40、TPS-80的DPPH自由基清除能力和羟基自由基清除能力测定结果的半抑制浓度值分别为157.03 μg/mL、98.71 μg/mL和0.65 mg/mL、0.64 mg/mL; TPS-40、TPS-80的铁离子还原能力分别为72.29 mmol Fe2+/g、77.45 mmol Fe2+/g。结论 两种多糖均具有较好的体外抗氧化活性, TPS-80由于其具有较低的分子量和较高的酸性糖含量, 体外抗氧化活性比TPS-40稍强。

英文摘要:

      Objective To study the preliminary characterization of two kinds of polysaccharides (TPS-40 and TPS-80) extracted and isolated from Dancong tea and their antioxidant activities in vitro. Methods The two kinds of polysaccharides were characterized by ion exchange column chromatography, dextran gel column chromatography, Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction spectroscopy. The scavenging ability of 2, 2-diphenyl -1-picrylhydrazyl (DPPH) free radicals, hydroxyl free radicals and iron reduction capacity of the two polysaccharides were determined, and their antioxidant activities in vitro were evaluated. Results The proportion of uronic acid of TPS-40 and TPS-80 was (54.25±0.25)% and (46.39±0.39)%, respectively, indicating that they were acidic polysaccharides. DEAE-52 column chromatography and dextran gel column chromatography showed that both polysaccharides had a main elution peak, indicating that their components were concentrated. The DPPH scavenging capacity and hydroxyl radical scavenging capacity of TPS-40 and TPS-80 were 157.03 μg/mL, 98.71 μg/mL, 0.65 mg/mL, 0.64 mg/mL, respectively. The iron reduction capacity of TPS-40 and TPS-80 was 72.29 mmol Fe2+/g and 77.45 mmol Fe2+/g, respectively. Conclusion Both polysaccharides has better antioxidant activity in vitro, but TPS-80 had stronger antioxidant activity than TPS-40 because of its lower molecular weight and higher acidic sugar content.