Preparative separation of seven phenolic acids from Xanthii Fructus using pH-zone-refining counter-current chromatography combined with semi-preparative high performance liquid chromatography.

Phenolic acids represented by caffeoylquinic acids in Xanthii Fructus have various pharmacological activities such as anti-inflammatory, anti-nociceptive, anti-oxidative and anti-allergic effects. In this study, pH-zone-refining counter-current chromatography was successfully applied in the segmentation of crude samples and further separation of phenolic acids from Xanthii Fructus. We initially segmented 1.

Extraction of isoflavones from using subcritical water.

As an alternative to organic solvents, subcritical water was employed for the first time as an effective solvent for the extraction of isoflavones from . Optimum experimental conditions for the extraction of the four main isoflavones were established by single factor experiments, and the optimum experimental conditions for total isoflavone extraction were established further by response surface methodology. With an extraction time of 45 min and a liquid/solid ratio of 1 : 20, the extraction yields of puerarin, 3'-methoxypuerarin, and daidzin reached maxima at extraction temperatures of 120 °C, 140 °C and 200 °C, respectively.