First separation of four aromatic acids and two analogues with similar structures and polarities from Clematis akebioides by high-speed counter-current chromatography.

In this paper, we report an efficient method by high-speed counter-current chromatography for the first separation of four aromatic acids and two analogs with similar structures and polarities from Clematis akebioides. First, the ethyl acetate extract was treated by silica gel column chromatography to enrich the target compounds. And then the fraction with target compounds were purified by high-speed counter-counter chromatography using a two-phase solvent system consisting of chloroform/acetonitrile/water (10:6:4, v/v). The results showed high-speed counter-current chromatography could be a powerful technology for the separation of compounds with similar structures and polarities. Besides, it was found acetonitrile could be a good methanol substitute when a chloroform/methanol/water system could not provide a good separation factor. This study provides a reference for the separation of compounds from Clematis akebioides.