Separation of Seven Polyphenols from the Rhizome of Smilax glabra by Offline Two Dimension Recycling HSCCC with Extrusion Mode

An offline two-dimensional recycling high-speed countercurrent chromatography (2D R-HSCCC) strategy with extrusion mode was developed for isolating polyphenols from the rhizome of . Firstly, the ethyl acetate extract was divided into two fractions, Fr.1 and Fr.2, by silica gel column chromatography. Then, HSCCC was applied to separate polyphenols from the two fractions using a solvent system consisting of petroleum ether-ethyl acetate-methanol-water (1:3:0.5:5, / ). Fifty milligrams of Fr.1 was separated by conventional HSCCC, yielding 5- -caffeoylshikimic acid ( , 15.8 mg) and taxifolin ( , 4.8 mg). Offline 2D R-HSCCC with extrusion mode was used to separate Fr.2, and astilbin ( , 37.3 mg), neoisoastilbin ( , 8.8 mg), engeletin ( , 7.9 mg), and a mixture of two polyphenols were obtained from 100 mg of Fr.2. The mixture of two polyphenols was further separated by pre-HPLC, yielding neoastilbin ( , 15.2 mg) and isoastilbin ( , 9.9 mg). The purities of these seven compounds were all over 96.0%. Their structures were identified by MS and NMR. The results demonstrated that the strategy based on offline 2D R-HSCCC with extrusion mode was a powerful tool to separate the main compounds from the rhizome of and valued for the preparative separation compounds with broad -values and similar structures.