Development and validation of a supercritical fluid chromatography method for fast analysis of six flavonoids in Citri Reticulatae Pericarpium.

The study is aimed to develop a rapid and efficient supercritical fluid chromatography coupled with diode-array detection (SFC-DAD) method for simultaneous quantification of six flavonoids in Citri Reticulatae Pericarpium (CRP). The chromatographic parameters including stationary phase, mobile phase composition, back pressure, temperature and flow rate, were systematically optimized with single-factor test. The results indicated that the six compounds were baseline separated on an Agilent Zorbax RX-SIL column using gradient elution within 10 min. The optimized mobile phase was constituted of carbon dioxide (CO2) and methanol. And the parameters were set as follows: backpressure, 95 bar; temperature, 45 °C; flow rate, 0.8 mL/min. The optimized method showed satisfactory retention and resolution for the analytes. The method was validated to demonstrate its selectivity, linearity, precision, accuracy and robustness. Thus, the verified SFC method was successfully applied to quantification of flavonoids present in CRP samples. The results indicated that SFC has the potential to become an excellent alternative for the analysis of flavonoids in herbal medicines, owning to its intrinsic features like high efficiency, separation speed and eco-friendly characteristics.

Rapid profiling of alkaloid analogues in Sinomenii Caulis by an integrated characterization strategy and quantitative analysis.

Alkaloids, the principal constituents in the caulis of Sinomenium acutum, have gained an increasing interest over the past decades since they are widely employed as a clinical treatment for rheumatoid arthritis. In the present study, an integrated characterization strategy by combining mass defect filtering-based structure classification (MDFSC) and diagnostic fragment-ion-based extension (DFIBE) was firstly proposed for rapid profiling of alkaloids in Sinomenii Caulis (SC) via ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). The rectangular MDFSC window could more accurately screen the target alkaloids of different types, and the DFIBE could facilitate the acquisition of characteristic fragment ions for structural elucidation of alkaloids. High-performance liquid chromatography (HPLC) fingerprints with principal component analysis (PCA) and hierarchical clustering analysis (HCA) was established for identifying the chemical markers and simultaneous determination of sinomenine, magnoflorine, menisperine, stepharanine and ehydrodiscretine. A total of 91 alkaloids, including 82 targeted ones (26 morphinans, 22 aporphines, 20 protoberberines and 14 benzylisoquinolines) were unambiguously identified or tentatively characterized in SC, and 14 of them were reported for the first time. Sinomenine and magnoflorine could be selected as chemical markers to evaluate the quality of SC from different localities. In conclusion, the proposed method provided a potential approach for chemical profiling and holistic quality control of herbal medicines.

Identification of anti-inflammatory components in Sinomenii Caulis based on spectrum-effect relationship and chemometric methods.

The present study aimed to identify the anti-inflammatory components in Sinomenii Caulis (SC) based on spectrum-effect relationship and chemometric methods. A phytochemical investigation of SC extract was performed firstly and afforded eleven potential bioactive compounds. The HPLC fingerprints of 19 batches of SC samples were evaluated by the chemometric methods such as similarity analysis (SA) and hierarchical clustering analysis (HCA). The anti-inflammatory effects of these samples were determined by inhibition of Nitric Oxide (NO) production. Partial least squares regression (PLSR) and artificial neural network (ANN) were used to explore the spectrum-effect relationship of SC. The results indicated that there was a close correlation between chemical fingerprint and anti-inflammatory activity of SC, and peaks 8, 9, 12, 13, 14, 16, 19 and 22 might be potential anti-inflammatory compounds in SC. The verification experiments by testing individual compounds and a combination of them indicated that sinomenine (P8), magnoflorine (P13), menisperine (P16) and stepharanine (P19) were the major anti-inflammatory compounds in SC. Collectively, the present study established the spectrum-effect relationship mode of SC and discovered the anti-inflammatory compounds in SC, which could be used for exploration of bioactive components and quality control of herbal medicines.

Comparison of Aurantii Fructus Immaturus and Aurantii Fructus based on multiple chromatographic analysis and chemometrics methods.

To get a better understanding of the bioactive constituents in Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF), in the present study, a comprehensive strategy integrating multiple chromatographic analysis and chemometrics methods was firstly proposed. Based on segmental monitoring, a high-performance liquid chromatography (HPLC)-variable wavelength detection method was established for simultaneous quantification of ten major flavonoids, and the quantitative data were further analyzed by hierarchical cluster analysis (HCA) and principal component analysis (PCA). A strong cation exchange-high performance liquid chromatography (SCX-HPLC) method combined with t-test and one-way analysis of variance (ANOVA) was developed to determine synephrine, the major alkaloid in AFI and AF. The essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS) and further processed by partial least squares discrimination analysis (PLS-DA). The results indicated that the contents of ten flavonoids and synephrine in AFI were significantly higher than those in AF, and significant difference existed in samples from different geographical origins. Also, 9 differential volatile constituents detected could be used as chemical markers for discrimination of AFI and AF. Collectively, the proposed comprehensive analysis might be a well-acceptable strategy to evaluate the quality of traditional citrus herbs.