[Analysis of chemical compositions in different parts of Isodon japonicus using UPLC-Q-TOF-MS technique combined with chemometrics].

In order to analyze the similarities and differences of chemical compositions between the roots and stems and leaves of Isodon japonicus(IJ), this study utilized UPLC-Q-TOF-MS technology to systematically characterize its chemical compositions, analyzed and identified the structure of its main compounds, and established a method for simultaneous determination of its content by refe-rence substance. A total of 34 major compounds in IJ, including 14 reference compounds, were identified or predicted online. Moreover, an UPLC-UV content determination method was developed for 11 compounds [danshensu, caffeic acid, vicenin-2,(1S,2S)-globoidnan B, rutin,(+)-rabdosiin,(-)-rabdosiin,(1S,2S)-rabdosiin, shimobashiric acid C, rosmarinic acid, and pedalitin]. The method exhibited excellent separation, stability, and repeatability, with a wide linear range(0.10-520.00 µg·mL~(-1)) and high linearity(R~2>0.999). The average recovery rates ranged from 94.72% to 104.2%. The principal component analysis(PCA) demonstrated a clear difference between the roots and stems and leaves of IJ, indicating good separation by cluster. Furthermore, the orthogonal partial least squares discriminant analysis(OPLS-DA) model was employed, and six main differentially identified compounds were identified: rosmarinic acid, shimobashiric acid C, epinodosin, pedalitin, rutin, and(1S,2S)-rabdosiin. In summary, this study established a strategy and method for distinguishing different parts of IJ, providing a valuable tool for quality control of IJ and a basis for the ratio-nal utilization and sustainable development of IJ.

[Rapid characterization and identification of non-volatile constituents in Pogostemonis Herba by UPLC-Q-TOF-MS combined with UNIFI and an in-house library].

This study aimed to characterize and identify the non-volatile components in Pogostemonis Herba by using ultra-perfor-mance liquid chromatography-quadrupole-time of flight-mass spectrometry(UPLC-Q-TOF-MS) combined with UNIFI and an in-house library. The chemical components in 50% methanol extract of Pogostemonis Herba were detected by UPLC-Q-TOF-MS in both positive and negative MS~E continuum modes. Then, the MS data were processed in UNIFI combined with an in-house library to automatically characterize the metabolites. Based on the multiple adduct ions, exact mass, diagnostic fragment ions, and peak intensity of compounds and the fragmentation pathways and retention behaviors of reference substances, the structures identified by UNIFI were further verified and those of the unidentified compounds were tentatively elucidated. A total of 120 compound structures were identified or tentatively identified, including flavonoids, phenylpropanoids, phenolic acids, terpenes, fatty acids, alkaloids, and phenylethanoid glycosides. Sixteen of them were accurately identified by comparison with reference substances, and 53 compounds were reported the first time for Pogostemonis Herba. This study systematically characterized and identified the non-volatile compounds in Pogostemonis Herba for the first time. The findings provide a scientific basis for revealing the pharmacodynamic material basis, establishing a quality control system, and developing products of Pogostemonis Herba.