Preparative separation of minor saponins from Platycodi Radix by high-speed counter-current chromatography
Preparative separation of minor saponins from Platycodi Radix by high-speed counter-current chromatography
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DOI：
10.1002/jssc.201100326
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发表时间：
2011-10-01
影响因子：
3.1
通讯作者：
Kim, Yeong S.
中科院分区：
文献类型：
--
作者：
Ha, In J.;Kang, Minseok;Kim, Yeong S.
桔梗皂苷(Platycoside，PSS)是桔梗Platycodon Grand diflorum(Jacq.)A.DC。(Platycodi Radix)，通常由具有两个侧链的齐烯主链组成；一个是通过糖苷键连接的3-O-葡萄糖，另一个是通过酯键连接的28-O-阿拉伯糖-鼠李糖-木糖-apiose。采用高速逆流色谱(HSCCC)和制备反相高效液相色谱(RP-HPLC)等多步分离方法，从桔梗中分离得到主要皂苷在鼠李糖2‘’和3‘’位的乙酰化异构体--次皂苷。在分离主要成分后，将浓缩后的次要皂苷部分用于本研究。HSCCC采用氯仿-甲醇-异丙醇-水(3：2：2：3，v/v)两相溶剂体系。HSCCC分离得到2‘’-O-乙酰化桔梗皂苷D、3‘’-O-乙酰化多聚半乳糖苷D、2‘’-O-乙酰化聚半乳糖酸以及3‘’-O-乙酰化桔梗皂苷D和聚半乳糖酸D的混合物。HSCCC分离后的混合物经制备反相高效液相色谱进一步纯化，得到纯度大于98.9%的3‘-O-乙酰化桔梗皂苷D和聚半乳糖酸D。建立的方法可用于桔梗粗提物中微量皂苷的制备和快速分离。据我们所知，这是HSCCC分离乙酰化PSS的第一次。
Platycosides (PSs), the saponins found in the root of Platycodon grandiflorum (Jacq.) A. DC. (Platycodi Radix), are typically composed of oleanene backbones with two side chains; one is a 3-O-glucose linked by a glycosidic bond, and the other is a 28-O-arabinose-rhamnose-xylose-apiose linked by an ester bond. Minor saponins, acetylated isomers of the major saponin on either the 2 '' or 3 '' position of rhamnose, were isolated from Platycodi Radix using a multi-step process including high-speed counter-current chromatography (HSCCC) and preparative reversed-phase high-performance liquid chromatography (RP-HPLC). After the separation of the major components, the enriched minor saponin fraction was used for this study. A two-phase solvent system consisting of chloroform-methanol-isopropanol-water (3:2:2:3, v/v) was used for HSCCC. HSCCC separation of the enriched minor saponin fraction yielded 2 ''-O-acetylplatycodin D, 3 ''-O-acetylpolygalacin D, 2 ''-O-acetylpolygalacin and a mixture of 3 ''-O-acetylplatycodin D and polygalacin D. The mixture fraction from HSCCC separation was further purified by preparative RP-HPLC, giving 3 ''-O-acetylplatycodin D and polygalacin D at a purity of over 98.9%. The developed method provides the preparative and rapid separation of minor saponins in the crude extract of Platycodi Radix. To the best of our knowledge, this is the first on the separation of acetylated PSs by HSCCC.