Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employ...Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employed to obtain the best possible combination of extraction time,pressure,temperature and ethanol content of modifier for maximum production.The optimum conditions were as follows:extraction time of 170 min,pressure of45 MPa,temperature of 75 ℃,and 50% aqueous ethanol solution as modifier.Under these conditions,the experimental yield was 6.56 ± 0.37%,which was similar to the value predicted by the model.Monosaccharide composition of TFPS was fucose,rhamnose,arabinose,xylose,galactose,glucose,mannose,fructose,ribose,galacturonic acid and glucuronic acid in a molar percent of 31.69,0.21,0.49,1.29,35.82,0.97,1.63,18.34,7.88,1.06 and 0.63.Compared to other extraction methods,SFE could achieve higher yield and gain more types of monosaccharide.展开更多
为探究香茶中多糖的组成及其结构特征,通过热水、草酸铵和NaOH对香茶进行浸提,经分级醇沉后,分别得到水提纯化香茶多糖(water-extracted Xiangcha tea polysaccharide at 40%ethanol concentration,WTP-40)、草酸铵提纯化香茶多糖(ammon...为探究香茶中多糖的组成及其结构特征,通过热水、草酸铵和NaOH对香茶进行浸提,经分级醇沉后,分别得到水提纯化香茶多糖(water-extracted Xiangcha tea polysaccharide at 40%ethanol concentration,WTP-40)、草酸铵提纯化香茶多糖(ammonium oxalate-extracted Xiangcha tea polysaccharide at 60%ethanol concentration,OTP-60)和碱提纯化香茶多糖(alkali-extracted of Xiangcha tea polysaccharides at 40%ethanol concentration,ATP-40),对3种多糖的理化特性、红外光谱、单糖组成及甲基化进行分析,并通过1D和2D核磁共振(nuclear magnetic resonance spectroscopy,NMR)对OTP-60进行结构解析。结果表明,3种香茶多糖均属于酸性糖,其中WTP-40(584 kDa和5 kDa)和ATP-40(1279 kDa和148 kDa)均含有2个不同相对分子质量的多糖片段,而OTP-60的相对分子质量分布较为均一,为869 kDa;3种多糖均属于低酯果胶,其中OTP-60的酯化度最高(41.9%)。单糖组成结果显示,3种多糖的主要成分均为半乳糖醛酸,且OTP-60的糖醛酸含量最高(87.33%)。甲基化和NMR结果表明,3种多糖的连接方式基本一致,OTP-60是具有同型半乳糖醛酸聚糖(homogalacturonan,HG)和鼠李半乳糖醛酸聚糖I型(rhamnogalacturonan-Ⅰ,RG-I)2种结构域的果胶,其中HG由→4)-α-Gal p A-(1→和→4)-α-Gal p A-6-O-Me-(1→组成。RG-I含有→4)-α-Gal p A-(1→和→2)-α-Rha p-(1→连接而成的主链,以及由Ara和Gal组成侧链分支。该文研究结果为香茶多糖的开发利用及构效关系研究提供了理论依据。展开更多
基金supported by a key research grant "The application and Utilization of Tea (Camellia sinensis) Flowers" from the 2013 Zhejiang Province
文摘Polysaccharide production from tea flower(TFPS) was carried out using supercritical fluid extraction(SFE).Response surface methodology(RSM),based on a five level,four variable small central composite design,was employed to obtain the best possible combination of extraction time,pressure,temperature and ethanol content of modifier for maximum production.The optimum conditions were as follows:extraction time of 170 min,pressure of45 MPa,temperature of 75 ℃,and 50% aqueous ethanol solution as modifier.Under these conditions,the experimental yield was 6.56 ± 0.37%,which was similar to the value predicted by the model.Monosaccharide composition of TFPS was fucose,rhamnose,arabinose,xylose,galactose,glucose,mannose,fructose,ribose,galacturonic acid and glucuronic acid in a molar percent of 31.69,0.21,0.49,1.29,35.82,0.97,1.63,18.34,7.88,1.06 and 0.63.Compared to other extraction methods,SFE could achieve higher yield and gain more types of monosaccharide.
文摘为探究香茶中多糖的组成及其结构特征,通过热水、草酸铵和NaOH对香茶进行浸提,经分级醇沉后,分别得到水提纯化香茶多糖(water-extracted Xiangcha tea polysaccharide at 40%ethanol concentration,WTP-40)、草酸铵提纯化香茶多糖(ammonium oxalate-extracted Xiangcha tea polysaccharide at 60%ethanol concentration,OTP-60)和碱提纯化香茶多糖(alkali-extracted of Xiangcha tea polysaccharides at 40%ethanol concentration,ATP-40),对3种多糖的理化特性、红外光谱、单糖组成及甲基化进行分析,并通过1D和2D核磁共振(nuclear magnetic resonance spectroscopy,NMR)对OTP-60进行结构解析。结果表明,3种香茶多糖均属于酸性糖,其中WTP-40(584 kDa和5 kDa)和ATP-40(1279 kDa和148 kDa)均含有2个不同相对分子质量的多糖片段,而OTP-60的相对分子质量分布较为均一,为869 kDa;3种多糖均属于低酯果胶,其中OTP-60的酯化度最高(41.9%)。单糖组成结果显示,3种多糖的主要成分均为半乳糖醛酸,且OTP-60的糖醛酸含量最高(87.33%)。甲基化和NMR结果表明,3种多糖的连接方式基本一致,OTP-60是具有同型半乳糖醛酸聚糖(homogalacturonan,HG)和鼠李半乳糖醛酸聚糖I型(rhamnogalacturonan-Ⅰ,RG-I)2种结构域的果胶,其中HG由→4)-α-Gal p A-(1→和→4)-α-Gal p A-6-O-Me-(1→组成。RG-I含有→4)-α-Gal p A-(1→和→2)-α-Rha p-(1→连接而成的主链,以及由Ara和Gal组成侧链分支。该文研究结果为香茶多糖的开发利用及构效关系研究提供了理论依据。
