An ultra high performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-quadrupole-orbitrap MS) method was developed to systematically analyze chemical constituents of Scutellaria barbata D. Don. The 70% methanol extract was separated on an Agilent Eclipse Plus Cl8 column (1.8μm, 150 mm×2.1 mm), and eluted with a gradient of methanol-acetonitrile-water containing 0.1% formic acid at a flow rate of 0.25 mL/min. Constituents were identified by HRMS in the negative ion mode using both full scan and two-stage threshold-triggered mass modes. A total of 56 compounds, including 20 free flavonoids, 20 flavonoid O-glycosides, 2 flavonoid C-glycosides, 4 phenylethanoid glycosides, and 10 phenolic compounds were identified by analyzing their high resolution mass spectral data. Among them, 8 flavonoids and 2 phenylethanoid glycosides were unambiguously identified by comparing with reference standards. This study demonstrates that hybrid quadrupole-orbitrap mass spectrometry is a powerful tool in structural identification of unknown compounds in comolicated herbal extracts.
Puerariae Radix (Ge-Gen in Chinese) is a popular traditional Chinese herbal medicine derived from the driedroots ofPueraria lobata (Willd.) Ohwi or P. thomsonii Benth. It shows significant pharmacological activities in the treatment ofcardiovascular diseases, hypertension, and diabetes. This review summarizes progress in the chemistry study of Puerariaspecies, mainly covering the classes of flavonoids, puerosides, coumarins, triterpenoids, and triterpene saponins. Qualitative andquantitative chemical analyses are also covered.