Preparative isolation and purification of dicaffeoylquinic acids from the Ainsliaea fragrans champ by high-speed counter-current chromatography

Two dicaffeoylquinic acids, namely 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid, have been successfully separated by high-speed counter-current chromatography (HSCCC) from an extract of Ainsliaea fragrans Champ, followed by an initial clean-up step using AB-8 resin. A two-phase solvent system composed of chloroform:methanol:water (8:8:4) was selected for the isolation with the aqueous-rich phase as the stationary phase and the organic-rich phase as the mobile phase. The developed HSCCC method yielded 34 mg of 3,5-dicaffeoylquinic acid and 17 mg of 4,5-dicaffeoylquinic acid from 150 mg of the crude sample in a one-step separation with purities of 98 and 95%, respectively, as determined by HPLC. The structures of the two compounds were identified from ESI/MS, (1)H- and (13)C-NMR spectroscopic data.