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

The chemical components in Taraxacum kok-saghyz Rodin (TKS) were analyzed and identified using ultra-high-performance liquid chromatography coupled with quadrupole/Orbitrap high-resolution mass spectrometry (UHPLC-Q/Orbitrap HRMS). The roots and leaves of TKS samples were dried and pulverized, and extracted by ultrasonic/microwave-assisted extraction (UMAE). A Waters ACQUITY BEH C18 column (100 mm×2.1 mm×1.7 μm) was used for gradient elution with 0.1% formic acid aqueous solution and acetonitrile as mobile phases. The eluent was ionized by atmospheric pressure chemical ionization (APCI) interface followed by data acquisition under full-scan MS/data-dependent MS/MS (Full-MS) mode. The obtained data were processed and then compared with the database of Orbitrap traditional Chinese medicine library (OTCML), online database, etc., based on the accurate mass-to-charge ratio of precursor ion, isotopic peak distribution, and the match of MS2 spectra. A total of 164 compounds were tentatively identified including flavonoids, coumarins, terpenoids, organic acids, alkaloids, lignins, etc. Meanwhile, the mass spectrometric fragmentation pathways of some identified components were deduced, which is helpful for the structural analysis of flavonoids and other compounds and provides an important experimental basis for the rapid identification of flavonoids and other structural analogs in TKS.