Identification of metabolites of Radix Paeoniae Alba extract in rat bile, plasma and urine by ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry （UPLC-Q-TOF/MS） was developed to identify the absorbed parent components and metabolites in rat bile, plasma and urine after oral administration of Radix Paeoniae Alba extract （RPAE）. A total of 65 compounds were detected in rat bile, plasma and urine samples, including 11 parent compounds and 54 metabolites. The results indicated that glucuronidation, hydroxylation and methylation were the major metabolic pathways of the components of RPAE. Furthermore, the results of this work demonstrated that UPLC-Q-TOF/MS combined with MetaboLynx？ software and mass defect filtering （MDF） could provide unique high throughput capabilities for drug metabolism study, with excellent MS mass accuracy and enhanced MSE data acquisition. With the MSE technique, both precursor and fragment mass spectra can be simultaneously acquired by alternating between high and low collision energy during a single chromatographic run.

Simultaneous Determination of Saponins in Dripping Pills Made from Astragali Radix and Panax notoginseng by UPLC-ELSD

Objective To develop a simple and fast method for removing polyethylene glycol （PEG） and simultaneous determination of fives saponins, i.e. astragaloside IV, noto- ginsenoside R1, ginsenoside Rgl, ginsenoside Rbl, and ginsenoside Rd in dripping pills made from Astragali Radix and Panax notoginseng. Methods The extraction method was based on a liquid-liquid extraction using water-saturated n-butanol and the quantitative determination was based on ultra-performance liquid chromatography coupled with evaporative light scattering detection （UPLC-ELSD）. The chromatographic analysis was performed on an Acquity UPLC HSS T3 column （100 mm ~ 2.1 mm, 1.8 IJm） with a gradient elution of acetonitrile-0.1% formic acid aqueous solution within a runtime of 15 min. Results Compared to different methods, the proposed method could remove the interference of PEG in formulation. And the calibration curves showed good linearity during the test ranges. The method was validated for limits of detection and quantification, precision, and reproducibility. The recoveries were within the range of 96.87% - 99.97%. In addition, the verified method was firstly applied to determination of the five active ingredients in Qishen Yiqi Dripping Pills （QYDP） simultaneously. Conclusion The contents of five active ingredients are stable and homogeneous in QYDP, which indicates that the method could be readily utilized as a quality evaluation method for this traditional Chinese medicine dripping pills made from AstragaliRadix and Panax notoginseng.