Preparative separation of anti-oxidative constituents from Rubia cordifolia by column-switching counter-current chromatography

✍ Scribed by Yanbin Lu; Ruilin Hu; Zhiyuan Dai; Yuanjiang Pan

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 166 KB
• Volume: 33
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.201000173

✦ Synopsis

Abstract

An effective column‐switching counter‐current chromatography (CCC) protocol combining stepwise elution mode was successfully developed for simultaneous and preparative separation of anti‐oxidative components from ethyl acetate extract of traditional Chinese herbal medicine Rubia cordifolia. The column‐switching CCC system was interfaced by a commercial low‐pressure six‐port switching valve equipped with a sample loop, allowing large volume introduction from the first dimension (1^st^‐D) to the second dimension (2^nd^‐D). Moreover, to extend the polarity window, three biphasic liquid systems composed of n‐hexane/ethyl acetate/methanol/water (1:2:1:2, 2:3:2:3, 5:6:5:6 v/v) were employed using stepwise elution mode in the 1^st^‐D. By valve switching technique the whole interested region of 1^st^‐D could be introduced to second dimension for further separation with the solvent system 5:5:4:6 v/v. Using the present column‐switching CCC protocol, 500 mg of crude R. cordifolia extract were separated, producing milligram‐amounts of four anti‐oxidative components over 90% pure. Structures of purified compounds were identified by ^1^H and ^13^C NMR.