Objective: To study the effect of different proportions of piper chinaroot and rheum palmatum on the dissolution rate of five effective components (aloe emodin, emodin acid, emodin, emodin, emodin methyl ether). Methods: The high performance liquid chromatography (HPLC) method was used to analyz the contents of five effective components of rheum palmatum in the extracts of different combination of piper chinaroot and rheum palmatum. The tests were carried out by Thermo C18 (250 mm×4.6 mm, 5 μm) by gradient elution with methanol and 0.1% phosphoric acid water solution as mobile phase at a flow rate of 1ml/min, the column temperature was 30 ℃ and the detection wavelength was 254 nm. Results: The linear ranges of aloe emodin, emodin acid, emodin, emodin, emodin methyl ether were 0.018 5-0.741 8, 0.017 9-0.717 8, 0.015 9-0.635 5, 0.054 2-2.167 2, 0.016 2-0.646 4 μg, respectively. The average recoveries of aloe emodin, emodin acid, emodin, emodin, emodin methyl ether were 94.35%, 95.50%, 100.61%, 96.27%, 97.39%, and the RSDs were 1.81%, 1.99%, 2.84%, 2.71%, and 1.86%, respectively. Compared with rheum palmatumby single extract, the content of aloe emodin and emodin were increased by 5 proportions (3:1, 2:1, 1:1, 1:2, 1:3), while the content of emodin and emodin methyl ether were decreased. Conclusions The optimal compatibility proportion of piper chinaroot and rheum palmatum is 1:1.

Objective:To develop the UPLC-MS/MS method for the determination of amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid in Taohe-Chengqi Decoction simutaneously. Methods:The separation was performed on Supelco Discovery C18, and isocratic elution was carried out with mobile phase consisting of acetonitrile - 4 mmol/L ammonium formate. The mass spectrometer was operated in the positive and negative ionization electrospray (ESI) mode using multiple monitoring (MRM) to analize of five ingredients. The precursor to product ion transitions monitored for amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid were m/z 458.2→296.0, 146.8→103.1, 283.7→239.9, 269.7→226.1 and 821.4→350.9, respectively. Results:Amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid were analyzed, the linear ranges were 0.001 6-0.102 4, 0.001 6-0.102 4, 0.001 6-0.102 4, 0.000 8-0.051 2 and 0.000 4-0.256 0 ng, respectively. The r were 0.998 7, 0.999 1, 0.999 5, 0.998 9 and 0.998 6, respectively. The recovery of five analytes ranges from 97.33% to 105.33% and the Relative Standard Deviations were all below 2.69%. Conclusion:This UPLC-MS/MS method is exclusive, rapid and sensitivewhich could be applied for the determination of amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid in Taohe-Chengqi Decoction.