茶皂素的提取纯化及其单当归酰基茶皂苷元的制取

Extraction and Purification of Tea Saponin and Preparation of Single Angeloyl theasapogenol

榨取茶油后的茶籽饼粕含有丰富的茶皂素。为了精确定位茶皂素的生物活性及其构效关系,设计合成多样性药物分子,分离茶皂素单体和制取明确结构的苷元成为必要。本试验采用水浴提取,树脂吸附及沉析获得茶皂素;通过酸水解、溶剂萃取、柱层析和高效液相色谱等方法制备其茶皂苷元,色谱和波谱定性定量。结果显示,茶饼中茶皂素的水提取条件为:料液比1∶25(m/V)、80℃水浴,提取2 h,3次。纯化条件为:茶皂素水提取液过AB-8型树脂,依次用水、稀碱、水和90%乙醇洗脱,醇洗脱液冰浴沉析3 h,离心获得茶皂素,纯度达96%。然后将其进行盐酸水解,条件为:3 mol/L盐酸60%甲醇水溶液,料液比1∶15(m/V),85℃回流水解5 h;再进行乙酸乙酯萃取、硅胶柱层析,收集石油醚-乙酸乙酯洗脱液,液相制备,获得2种茶皂素苷元,波谱数据并与文献比对,确定其结构为:21-当归酰基-22-乙酰茶皂苷元Ⅰ和Ⅱ,两者仅有C4位甲基和醛基差别。

Tea seed cake is the by - product of tea seed oil extracted and rich in tea saponin. In order to locate accurately its relationship between biological activity and structure -activity, design and synthesis of multifarious molecular drug, separation of tea saponin monomer and preparation of theasapogenol with explicit structure become necessary. In this paper, tea saponins were obtained using water bath extraction, resin adsorption and precipitation. The theasapogenols were prepared using acid hydrolysis, solvent extraction, column chromatography and HPLC. Qualitative and quantitative analysis of theasapogenol was performed by chromatography and spectrum. The results showed that the conditions for the water extraction of tea saponins were ： ratio of material to liquid ： 1 ： 25 （m/V） , under water bath at 80℃ for 2 h, triplicate. Purification conditions were as follows： Tea saponins were purified by AB -8 resin with elution H2O, 0.1% NaOH, H2O and 90% ethanol successively, then precipitated 3 h, centrifuged and obtained with purity 96%. Two theasapogenols were prepared by the process of acid hydrolysis in 3 mol/L 60% HCl- Methanol aqueous solution with the ratio of material to liquid 1：15 （m/V）, reflux at 85 ℃ for 5 h; extract with ethyl acetate, elution through silica gel column with petroleum ether - ethyl acetate, and semi - preparative HPLC. The theasapogenols were identified as 21 - O - angeloyl - 22 - O - acetyl theasapogenol Ⅰ and Ⅱ according to their spectrum data and compared with literatures. Theasapogenol Ⅰ differs from theasapogenol Ⅱ only at the group C -4 position, 4 - aldehyde or 4 - methyl.