Identification of Chemical Components in Taraxacum kok-saghyz Rodin and Investigation of Mass Spectrometric Fragmentation Pathways

Taraxacum kok-saghyz Rodin, a perennial herbaceous plant of the genus Taraxacum (Asteraceae), has widely distributed in Europe, the Americas, and northwestern and northeastern China. However, the specific bioactive compounds responsible for its pharmacological effects remain uncharacterized, necessitating experimental validation to establish a theoretical foundation. This study systematically characterized the chemical constituents of Taraxacum kok-saghyz Rodin, a medicinal plant of the dandelion genus, using ultra-high-performance liquid chromatography coupled with quadrupole/Orbitrap high-resolution mass spectrometry (UHPLC-Q/Orbitrap HRMS). The sample pretreatment process involved optimizing solvent selection. One gram of dried rubber dandelion root or leaf powder was mixed with methanol and subjected to ultrasonic/microwave-assisted extraction (microwave power of 450 W, ultrasonic power of 550 W, temperature of 50 ℃, and extraction time of 30 min), followed by chromatographic separation on an ACQUITY UHPLC BEH C18 column (150 mm×2.1 mm, 1.7 µm) at 40 ℃, with an injection volume of 3 μL per run. The mobile phase consisted of water containing 0.1% formic acid and 2.5 mmol/L ammonium formate (A) and acetonitrile (B) at a flow rate of 0.3 mL/min. Electrospray ionization (ESI) was employed for ionization. Full scan/data-dependent tandem mass spectrometry (MS/MS) scan (Full MS/dd-MS²) acquisition mode ensured comprehensive coverage of precursor and fragment ions, with a scan range of m/z 80-1 200. Full scan resolution was set at 60 000, while dd-MS² scan resolution reached 15 000. The raw data were processed using Xcalibur 4.1 software for chromatographic peak alignment and extraction. Accurate mass information for precursor and fragment ions was meticulously compared with three databases of the Orbitrap Traditional Chinese Medicine Library (OTCML), a self-curated database, and the Global Natural Products Social Molecular Networking online platform. A total of 94 compounds were identified, encompassing 4 flavonoids, 5 alkaloids, 11 terpenoids, 8 phenolics, 6 amino acids, 13 phenylpropanoids, 10 organic acids, 4 nucleotides, and 33 other types of compounds. To ensure the accuracy of compound identification, reference standards (chlorogenic acid, caffeic acid, p-coumaric acid, 7-hydroxycoumarin, and ferulic acid) were subjected to mass spectrometric characterization, effectively eliminating false-positive interferences. This study revealed that amino acids and phenylpropanoids exhibit higher mass spectrometric responses, whereas alkaloids show weaker responses. By analyzing the fragmentation pathways of representative compounds, the structural characteristics were elucidated, providing a scientific basis for deciphering the pharmacodynamic material foundation of non-latex components in Taraxacum kok-saghyz Rodin. This study also offers data support for exploring the high-value utilization of non-rubber components in Taraxacum kok-saghyz Rodin. Taraxacum kok-saghyz Rodin exhibits a complex matrix composition and a diverse array of natural constituents. Future research prospects should integrate nuclear magnetic resonance (NMR) spectroscopy with artificial intelligence (AI)-driven pattern recognition methodologies to enhance data accuracy and improve the comprehensiveness of phytochemical characterization.