儿茶素单体分离制备方法

茶叶中含有丰富的儿茶素类物质,占茶叶干重12%～24%,是茶叶中最具生理活性和保健功效的物质。文中对目前国内外纯化制备儿茶素的常见方法进行了综述。常见的儿茶素制备方法包括纤维素柱层析、葡聚糖凝胶(Sephadex LH—20)、硅胶柱层析、吸附树脂柱层析和高速逆流色谱等方法。通过这些方法制备的儿茶素单体纯度不高,仍需结合结晶、制备型液相色谱技术或膜分离技术进行进一步纯化,从而才能获得高纯度的儿茶素单体。在儿茶素单体的制备方法中,每种方法都有相应的优缺点。Sephadex LH—20柱层析分离的量较大,但是分离时间较长,而且Sephadex LH—20柱填料昂贵;高速逆流色谱分离效果较好,得到的儿茶素单体的纯度较高,分离时间相对要短,但是目前市场上只有分析型,分离的量相对少;硅胶材料廉价,但是分离的效果不佳,且分离过程相对繁琐,单体制备量较小;吸附树脂柱层析分离已实现EGCG单体的工业化生产,但在其他儿茶素单体的分离制备上尚不成熟。

Review on Separation and Preparation of Catech ins from Tea

Catechins are the main secondary metabolites of tea,accounting for 12%～24% of dry weight in fresh tea leaves,and are principally responsible for many biological activities and health-care function. Many methods of separation and preparation of catechin,including cellulose column chromatography,Sepha- dex LH—20 chromatography,silica gel column chromatography,adsorption resin column chromatography and high-speed countercurrent chromatography (HSCCC) were briefly summarized in this paper.However, the purity of catechin obtained by those methods was not high.It is necessary to combine with other methods such as crystallization,preparative HPLC chromatograms and membrane filtration technology to get the par- ticular catechin monomer with high purity.Those methods had its advantages and disadvantages for separa- tion and preparation of catechins.The amount of catechins obtained by Sephadex LH—20 was more than that gotten by others.However,it is time consuming and expensive.The effect of using HSCCC to separate cate- chins was very well,but the instrument is only available as the analysis model at labs.Although the price of silica gel was cheap,the separation process of using silica gel column chromatography was very complicated and the separation efficiency was low.So far,the large—scale preparation of EGCG by adsorption resin col- umn chromatography has been applied for industrial production,but there is not an efficient method to prepa- ration other type of catechins for industry.