葡聚糖凝胶LH-20分离制备生物碱、无咖啡碱茶多酚和茶色素工艺研究

Study on the method of separation and preparation purine alkaloids , noncaffeine tea polyphenols and tea pigments in one-step by sephadex LH-20

本研究建立了一种环保高效同时分离制备生物碱、无咖啡碱茶多酚和茶色素的葡聚糖凝胶LH-20柱层析方法。第一步使用蒸馏水分离茶色素和生物碱;第二步采用60%(v/v)乙醇溶液反向洗脱得到无咖啡碱茶多酚产品。经定量分析,生物碱得率3.14%,其中含93.87%咖啡碱和6.08%可可碱。茶多酚的得率为12.27%,纯度为98.13%,其中儿茶素含量高达90.28%,抗氧化活性最强的EGCG含量达61.17%,咖啡碱未检出。柱层析对生物碱和茶多酚的回收率分别为98.14%和86.36%。副产的茶色素主要含有一些多酚氧化物以及黄酮苷类混合物,可作为天然色素利用。

A simple and clean method of separation and preparation purine alkaloids,noncaffeine tea polyphenols and tea pigments from green tea by sephadex LH-20 column chromatography was developed. Distilled water was used as the eluting agent for purine alkaloids and tea pigments in the first stepwise elution,and tea polyphenols was eluted with 60%（v/v） ethanol solution by using reversed flow in the second stepwise elution. The yield of purine alkaloids was 3.14% with the 93.87% caffeine and 6.08% theobromine. The yield of tea polyphenols was 12.27% with the purity about 98.13% and the content of catechins was 90.28%. The content of EGCG which had the strongest antioxidant activity was 61.17%,and the content of caffeine in tea polyphenols had not been detected by high-performance liquid chromatography（HPLC）. The recovery of tea polyphenols and purine alkaloids by column chromatography were 98.14% and 86.36% respectively. The byproduct of tea pigment containing polyphenol oxides and flavonoid glycosides mixture,can be used as natural pigments.