Comparison of Geqingpi and Sihuaqingpi based on ultra-high-performance liquid chromatography-tandem mass spectrometry combined with multivariate statistics, network pharmacology analysis, and molecular docking.

Citri Reticulatae Pericarpium Viride is used in traditional Chinese medicine as Geqingpi and Sihuaqingpi varieties. We used the ultra-high-performance liquid chromatography-quadrupole-Exactive Orbitrap-mass spectrometry method and high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry to analyze the chemical compounds in these varieties. Principal components analysis and orthogonal partial least squares discriminant analysis were used to analyze the quantitative results. Network pharmacology and molecular docking technology were used to forecast Citri Reticulatae Pericarpium Viride treatment mechanisms in irritable bowel syndrome. We identified 44 main compounds in Citri Reticulatae Pericarpium Viride. Compared to Sihuaqingpi, Geqingpi had higher narirutin, didymin, naringenin, and hesperetin, and lower hesperidin, isosinensetin, nobiletin, 3,5,6,7,8,3',4'-hexamethoxyflavone, tangeretin. Tangeretin, nobiletin, narirutin, didymin, and isosinensetin were the main compounds distinguishing Geqingpi from Sihuaqingpi. We found that the MAPK signaling pathway, which is closely related to irritable bowel syndrome, was an important target pathway. TP53, HRAS, MAPK1, AKT1, and EGFR were important targets in this pathway. Eriodictyol-7-O-rutinoside, narirutin, limonin, and hesperidin showed a good binding ability to the five targets. Orientin, unique to Sihuaqingpi, bound well to TP53, MAPK1, AKT1, and EGFR, while rhoifolin bound well to TP53, HRAS, MAPK1, AKT1, and EGFR. Hesperetin, unique to Geqingpi, bound well to TP53, HRAS, and MAPK1, while naringenin bound well to HRAS. Hesperidin and didymin bound well to TP53, MAPK1, AKT1, and EGFR.

Analyses of Physical and Chemical Compositions of Different Medicinal Specifications of CRPV by Use of Multiple Instrumental Techniques Combined with Multivariate Statistical Analysis.

Citri Reticulatae Pericarpium Viride (CRPV) is the processed product of Citrus reticulata Blanco. We systematically analyzed two CRPV types, Geqingpi (GQP) and Sihuaqingpi (SHQP), based on powder color, microscopic characteristics, and chemical composition. In addition, we characterized their constituents via ultra-high-performance liquid chromatography with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS). Both showed significant differences in their powder color and microscopic characteristics. Fourier-transform infrared (FT-IR) spectroscopic analysis results showed that the C=O peak absorption of carboxylic acids and their carbonyl esters in SHQP was higher than that of GQP, while the C-OH and C-H plane bending peaks of polysaccharides were lower than those of GQP. We analyzed these data via similarity analysis, PCA, and OPLS-DA. GQP and SHQP had large distinct differences. Based on the mass measurements for molecular and characteristic fragment ions, we identified 44 main constituents from CRPV, including different flavonoid glycosides and flavonoid aglycones in SHQP and GQP, respectively. We found luteolin-6-C-glucoside, orientin, rhoifolin, and pilloin solely in SHQP, and naringenin and hesperetin only in GQP. The peak area measurements showed GQP having a higher flavonoid glycoside (narirutin, hesperidin, etc.) content, whereas SHQP had a higher polymethoxyflavone (nobiletin, tangeretin, etc.) content. Since we holistically analyzed two CRPV types, the results can not only support future pharmacological research, but also provide a scientific basis for formulating more reasonable CRPV quality standards and guide its clinical potential as a precision medicine.

[Research advances of chemical constituents and analytical methods of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium].

Citri Reticulatae Pericarpium Viride(CRPV) and Citri Reticulatae Pericarpium(CRP) are two commonly used Chinese medicinal materials. They have the same origin while are harvested in different seasons and have different clinical effects. They contain similar chemical components, like flavonoids, terpenes, volatile oils, and alkaloids. Although it has been demonstrated that differential components exist between them, there is still a lack of systematic comparison. Many studies have reported the chemical composition and quality evaluation of CRPV and CRP, including the characterization of flavonoids, alkaloids, and volatile oils via thin-layer chromatography, high-performance liquid chromatography, gas chromatography, infrared spectroscopy, and ultraviolet spectroscopy. A few studies have explored the differences between CRPV and CRP. In this paper, we systematically summarized the reported chemical composition, analytical methods, and quality evaluation of CRPV and CRP in recent ten years, aiming to facilitate the research on the pharmacodynamic material basis, quality evaluation, and standard improvement of CRPV and CRP.

Simultaneous quantitative analysis of ten bioactive flavonoids in Citri Reticulatae Pericarpium Viride (Qing Pi) by ultrahigh-performance liquid chromatography and high-resolution mass spectrometry combined with chemometric methods.

INTRODUCTION: Citri Reticulatae Pericarpium Viride (Qing Pi in Chinese) is a clinically effective Chinese herb, which contains biologically valuable flavonoids. Qing Pi is divided into two commodity specifications, Si Hua Qing Pi (SHQP) and Ge Qing Pi (GQP), based on the harvesting time. The flavonoid contents in Qing Pi from different origins and commodity specifications may vary significantly, which will affect their therapeutic functions. Thus, it is crucial to set up a reliable and comprehensive quality evaluation method for flavonoid analysis in Qing Pi. OBJECTIVES: We aimed to establish a rapid and sensitive ultrahigh-performance liquid chromatography method coupled with diode-array detection and high-resolution mass spectrometry (UPLC-DAD-HRMS) for identification and quantification of ten flavonoids in Qing Pi. Chemometric methods were further applied to distinguish Qing Pi of different origins and specifications. METHODOLOGY: An UPLC-DAD-HRMS method was developed for the simultaneous separation and quantification of ten flavonoids in 46 batches of Qing Pi samples from different sources in China. Chemometric approaches were applied to discriminate Qing Pi from different origins and commodity specifications. RESULTS: The chemometric procedures (i.e., hierarchical clustering analysis and principal component analysis) were employed to identify the differences of Qing Pi samples with different origins and commodity specifications. The results showed that the contents of ten flavonoids in Qing Pi samples of different origins were significantly different, and the same results were found out between SHQP and GQP. CONCLUSIONS: This study provides a chemical basis for quality control of Qing Pi.

[Metabolic and excretory process of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium in rats' urine and feces analyzed by RRLC-QqQ-MSn].

This present study was to investigate the metabolism and excretion of characteristic polyphenols such as flavonoids and coumarins in urine and feces of rats after intragastric administration of ethanol extracts of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium. The urine and feces of rats were collected after intragastric administration of 70% ethanol extracts of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium. Rapid resolution liquid chromatography coupled with quadrupole tandem mass spectrometry (RRLC-QqQ-MSn) was applied to compare the contents of polyphenols in ethanol extract, urine and feces. By comparing with reference substance, 30 polyphenols were identified from the ethanol extracts of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium, including flavone glycosides, flavones, flavonone glycosides, flavonones, flavonol glycosides, polymethoxyflavones, coumarins, and limonoids and so on. The detection of various types of compounds showed differences in contents between the intestinal metabolism and excretion in the feces after systemic circulatory metabolism and renal excretion. The results showed that the polymethoxyflavones and flavonones were primarily excreted through urine, and the flavonone glycosides and limonoids were primarily excreted through feces. However, coumarins were hardly detected in feces and urine, indicating that coumarins may be metabolized in the body.

Identification of volatile and nonvolatile compounds in Citri Reticulatae Pericarpium Viride using GC-MS, UPLC-Q-Exactive Orbitrap-MS, and HPLC-PDA.

Gas chromatograph-mass spectrometer (GC-MS), ultra-high-performance liquid chromatograph-Q-Exactive Orbitrap tandem mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS), and high-performance liquid chromatography-photodiode array detection (HPLC-PDA) were used to qualitatively and quantitatively analyze the chemical component of Citri Reticulatae Pericarpium Viride "Geqingpi" (GQP). First of all, the volatile components of GQP are identified by GC-MS. Totally 56 volatile components were determined, and γ-Terpinene (33.39%) and D-Limonene (22.95%) were the main terpenes. Secondly, UHPLC-Q-Exactive Orbitrap-MS was used for identifying nonvolatile compositions and 42 compositions were identified totally, including 23 flavonoids, nine organic acids, three coumarins, two alkaloids compounds, and five other compounds, among which nine of the determined constituents were detected for the first time in GQP. Thirdly, the content of seven main constituents in GQP was quantitatively analyzed via HPLC-PDA, which were synephrine, hesperidin, limonin, nobiletin, HMF, tangeretin, and 5-HPMF. Further investigation for quantitative analysis of seven bioactive compounds suggested that the concentration of hesperidin in GQP approximately was 16.0% (160.78 ± 0.95 mg·g-1), which was far higher than the standard for identification and quality control of CRPV in Chinese Pharmacopoeia (2020 edition) that "the content of hesperidin shall not be less than 5.0%." The phytochemicals of GQP were elucidated in this study, which might be supporting information for identification between GQP and Citri Reticulatae Pericarpium Viride "Sihuaqingpi" (SHQP) and provided a scientific basis for the further active ingredient for pharmacological research and development prospects of GQP.