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Three flavones were prepared, isolated and purified from Pericarpium Citri Reticulatae by high-speed counter-current chromatography (HSCCC). A two-phase solvent system composed of light petroleum-ethyl acetate-methanol-water (2:4:3:3, v/v/v/v) was used. Within 6 hours, 10.1 mg of heseridin, 49.8 mg of 5,6,7,8,4'-pentamethoxyflavone and 50.6 mg of 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone with their purities over 97.0% were obtained from 4.0 g of the crude extract of Pericarpium Citri Reticulatae in one-step elution under the conditions of a flow rate of 1.70 mL/min, 800 r/min and the detection wavelength of 280 nm. The obtained fractions were analyzed by high performance liquid chromatography (HPLC), and identified by mass spectrometry (MS), 1H-nuclear magnetic resonance (NMR) and 13C-NMR. The results indicate that HSCCC is a powerful technique for the purification of flavones from Citrus reticulata Blanco.

A high performance liquid chromatographic (HPLC) method was developed for the determination of four acetophenones, namely 4-hydroxyacetophenone (I), 2,5-dihydroxyacetophenone (II), baishouwubenzophenone (III) and 2,4-dihydroxyacetophenone (IV), in Radix Cynanchi bungei. The HPLC with photodiode array (PDA) detection was carried out on a Symmetry-C18 (4.6 mm x 250 mm, 5 microm) column with CH3OH-H2O (26 : 74, v/v) as the mobile phase at the flow rate of 1.0 mL/min and 30 degrees C. The compounds I , III, IV were monitored at 280 nm, and the compound II was at 224 nm. Four acetophenones (I - IV) had good linearities (r = 0.999 6 - 0.999 9) at the ranges of 0.080 - 0.560 microg, 0.080 -0.560 microg, 0.100 - 0.700 microg and 0.092 -0.644 microg, respectively. The average recoveries were from 98.0% to 104.0% with relative standard deviations (RSD) ranging from 0.8% to 2.6%. The method is of quick, simple and accurate. The method can be used for the quality control of this product.