Large-scale preparation of two minor polar polyphenols from Phyllanthus emblica Linn. by macroporous resin column chromatography and high-temperature preparative high-speed counter-current chromatography.

In the present study, an efficient strategy for the large-scale preparation of two minor polar polyphenols from Phyllanthus emblica L. has been established by macroporous resin column chromatography and high-temperature preparative high-speed counter-current chromatography. Macroporous resin column chromatography was used for the enrichment of the target polyphenols. The target polyphenols could be well enriched in the 10% ethanol fraction and the peak area proportion increased from 2.2% in the crude extract to 85.3% in the 10% ethanol fraction. Then, the 10% ethanol fraction was introduced to preparative high-speed counter-current chromatography for separation using an n-butanol-ethyl acetate-water (17:3:20, v/v/v) solvent system. In order to improve the retention of the stationary phase, a high-temperature preparative high-speed counter-current chromatography had been developed by using a 316 L stainless steel pipe as a column. A 50°C of column temperature was used and the retention rate of the stationary phase could reach 75%. Finally, 871 mg of compound Ⅰ and 534 mg of compound Ⅱ with purities higher than 98% were obtained from 4 g of the sample. The chemical structures were identified as corilagin and 1, 6-di-O-galloyl-β-D-glucoside by 1 H-NMR and 13 C-NMR.