Isolation of chemical compounds from Sorbus tianschanica Rupr by high-speed counter-current chromatography

Sorbus tianschanica Rupr has been used as a pharmacologically valuable plant in Xinjiang to treat tuberculosis, asthma, cough and gastritis for a long time. Four compounds including three flavonoids and chlorogenic acid were isolated and purified by high-speed counter-current chromatography (HSCCC) from S. tianschanica Rupr. The two-phase solvent system composed of n-hexane - ethyl acetate - n-butanol - water (2:6:1:8, v/v). Consequently, chlorogenic acid (1), Quercetin-3-O-(6''-O-malonyl)-β-D-glucoside (2), Kaempferol-3-O-(6''-O-malonyl)-β-D-glucopyranoside (3) and Kaempferol-3-O-β-D-glucopyranoside (4) were obtained from 250 mg crude extracts with purities of 93, 91, 89 and 96%, respectively in a single run. The chemical structures were confirmed by mass spectrometer (MS), 1H nuclear magnetic resonance (NMR) and 13C NMR. To our knowledge, compounds (2) and (3) were obtained from S. tianschanica Rupr for the first time.   Key words:  High-speed counter-current chromatography, Sorbus tianschanica Rupr, flavonoids, chlorogenic acid.