[Simultaneous isolation and purification of gallic acid and brevifolincarboxylic acid from Polygonum capitatum by high-speed counter-current chromatography]

Objective: To isolate and purify gallic acid and brevifolincarboxylic acid simultaneously by high-speed counter-current chromatography (HSCCC) from a crude extract of Polygonum capitatum.

Method: The biphasic solvent system composed of ethyl acetate-n-butanol-0.44% acetic acid (3:1:5) was used at a flow rate of 2.0 mL x min(-1), while the aqueous phase was selected as the mobile phase and the apparatus was rotated at 860 r x min(-1). The effluent was detected at 272 nm.

Result: 51.5 mg of gallic acid and 5.9 mg of brevifolincarboxylic acid were separated from 1.07 g of the crude extract with the purities of 99.7% and 97.5%, respectively, while brevifolincarboxylic acid was obtained firstly from the genus Polygonum. The structures of the compounds were identified by ultraviolet spectrometry (UV), infra-red spectrometry (IR), liquid chromatography/mass spectrometry (LC/MS), time-of-flight mass spectrometry( TOF-MS), 1H-nuclear magnetic resonance (NMR) and 13C-NMR.

Conclusion: This method is feasible and rapid for isolation and purification of gallice acid and brevifolincarboxylil acid.