PDF(Pubmed)
Abstract：
Tea is a popular beverage with a long history of safe and healthy use. Tea polysaccharide is a bioactive component extracted from tea, which has attracted more and more attention in recent decades. In this article, an acidic polysaccharide Gougunao tea polysaccharide (GPS) was isolated from Gougunao green tea by hot water extraction and ethanol precipitation. After purification by a diethylaminoethyl (DEAE) Sepharose Fast Flow column and a Sephacryl S-400 column, several homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) fractions were obtained. Fraction GPS2b with the highest yield was selected for structural characterization by methylation and nuclear magnetic resonance (NMR) analysis. GPS2b was found to be an HG-type pectic polysaccharide (degree of methyl esterification [DE], 51.6%) with low molecular weight (M w , 36.8 kDa). It was mainly composed of →4)-α-GalpA- (1→ and →4)-α-GalpA-6-OMe-(1→. In addition, a minor highly branched RG-I domain was identified in this fraction. The investigation of structural features of tea polysaccharides can provide insights to understand their structure-bioactivity relationship.
摘要：
茶是一种受欢迎的饮料，具有悠久的安全和健康使用历史。茶多糖是从茶叶中提取的一种生物活性成分,近几十年来引起了越来越多的关注。在这篇文章中,通过热水提取和乙醇沉淀法从高古脑绿茶中分离出酸性多糖高古脑茶多糖（GPS）。通过二乙基氨基乙基（DEAE）SepharoseFastFlow柱和SephacrylS-400柱纯化后，获得了几种高半乳糖醛酸（HG）和鼠李糖半乳糖醛酸-I（RG-I）级分。通过甲基化和核磁共振(NMR)分析选择具有最高产率的级分GPS2b用于结构表征。发现GPS2b是HG型果胶多糖(甲酯化程度[DE]，51.6%)，具有低分子量(Mw，36.8kDa)。它主要由→4）-α-GalpA-（1→和→4）-α-GalpA-6-OMe-（1→。此外,在该部分中鉴定出次要的高度分支的RG-I结构域。研究茶多糖的结构特征可以为理解其结构-生物活性关系提供见解。
