Systematic characterization of the chemical constituents in vitro and in vivo of Qianghuo by UPLC-Q-TOF-MS/MS.

The Chinese herb Qianghuo is an antiphlogistic herb with many effects and complex components. In this study, the chemical composition of Qianghuo and its components in rat plasma after oral administration were investigated using ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). The extracts, blank plasma, and plasma containing the drug were analyzed by mass spectrometry, and data collected in both positive and negative ion modes were analyzed using Masslynx software, and the structures were confirmed by combining the compound fragment ions and mass spectrometry cleavage pathways. A total of 62 in vitro chemical components were identified, including 27 coumarins, 18 organic acids, 5 amino acids, 5 glycosides, 2 flavonoids, 4 nucleotides, and 1 ester, which were summarized from the obtained compounds in terms of their possible cleavage patterns. Among the identified 31 compounds in rat plasma, 21 were prototypes, mostly coumarins, organic acids, and flavonoids, and 10 were metabolites, which were mainly generated via hydroxylation and methylation pathways. Based on these, this study provides a theoretical foundation for quality control and basic research on Qianghuo medicinal substances.

Comparative studies of immobilized polysaccharide derivatives chiral stationary phases for enantioseparation of furanocoumarins and dihydroflavones and discussion on chiral recognition mechanism.

Enantiomeric separation of furanocoumarins and dihydroflavones compounds were systematically studied in the normal-phase mode using four different polysaccharide-type chiral stationary phases, namely, Chiralpak IA, Chiralpak IC, Chiralpak IG, and Chiralpak IK-3 by high-performance liquid chromatography. The effect of alcohol modifiers and alcohol content on enantiomeric separation was evaluated for the separation of furanocoumarins and dihydroflavones. All the eight compounds have achieved baseline separation with the resolutions ranging between 1.52 and 23.11. For a better insight into the enantiorecognition mechanisms, thermodynamic analysis was carried out. The mechanisms of chiral recognition have been discussed. Among four chiral columns, Chiralpak IG exhibited the most universal and the best enantioseparation ability toward furanocoumarins and dihydroflavones when used n-hexane-isopropanol and n-hexane-ethanol as mobile phase, respectively. The steric hindrance, hydrogen bonding, and π-π interaction played major roles in chiral recognition on Chiralpak IG. By comparing four chiral columns, this work systematically analyzed the separation methods of furanocoumarins and dihydroflavones for the first time and reported some active chiral ingredients of traditional Chinese medicine that have never been separated, which provided a further insight into the enantioseparation of furanocoumarins and dihydroflavones on chiral stationary phases.

A practical method for rapid discrimination of constituents in Psoraleae Fructus by UPLC-Q-Orbitrap MS.

Psoraleae Fructus (PF) is one of the most frequently used traditional Chinese medicine, which has good efficacy in warming kidney to activate yang, promoting inspiration to relieve asthma and warming spleen to stop diarrhea. However, the chemical composition of PF is complex, which makes it difficult to determine its active and toxic components. In order to rapidly classify and identify the chemical components of the extracts from PF, this research was processed with CNKI, PubMed, and PubChem databases and data post-processing technique basing on ultrahigh performance liquid chromatography quadrupole orbitrap mass spectrometry (UPLC-Q-Orbitrap MS) technique. Finally, 73 chemical components were discriminated, including 44 flavonoids, 18 coumarins, and 11 terpenoids, with the cleavage rules of each chemical component summarized. This study established a UPLC-Q-Orbitrap MS method for the separation and discrimination of the chemical constituents of PF, which can lay a foundation for the further study of its medicinal substances and quality control.

Enantioseparation and determination of oxypeucedanin and its application to a stereoselective analysis in Angelica Dahuricae Radix and pharmacokinetic study of rats.

In this study, a new enantioseparation method was established for the quantitative analysis of the oxypeucedanin enantiomers by using cellulose tris(3,5-dichlorophenyl carbamate) stationary phase column Chiralpak IC. For this method, enantiomeric separation of oxypeucedanin was achieved with the mobile phase consisting of acetonitrile-water (60:40, v/v) at a flow rate of 0.5 mL/min by changing the type and proportion of mobile phase. And the quantitative determination of racemic oxypeucedanin in Angelica Dahuricae Radix (in vitro) and rat plasma (in vivo) were performed on above-mentioned condition by High PerformanceLiquid Chromatography combined with diode arrangement detector (HPLC-DAD) and mass spectrometry (HPLC-MS/MS). The precision, repeatability, stability, recovery were within the acceptance criteria. And the method was validated in the concentration range of 1-400 µg/mL for the two enantiomers in vitro and 0.2-600 ng/mL in vivo. After validation, the established method was successfully applied to the stereoselective analysis of racemic oxypeucedanin in Angelica dahurica from different regions and the stereoselective pharmacokinetic investigation in rat. Results showed that the (+)-oxypeucedanin was at a relative high level in Angelica dahuricae Radix and (-)-oxypeucedanin performed a higher plasma concentration, which demonstrated the difference of oxypeucedanin enantiomers both in vitro and in vivo.