Component Analysis of Fraxini Cortex Based on UPLC-Q-Exactive Orbitrap MS

OBJECTIVE To analyze the composition of Fraxini Cortex by using ultra performance liquid chromatography- quadrupole electrostatic field orbitrap high-resolution mass spectrometry(UPLC-Q-Exactive Orbitrap MS). METHODS Halo 90Å C₁₈(2.1 mm×100 mm, 2.7 μm) as a chromatographic column, 0.05% formic acid aqueous solution(A)-0.05% formic acid acetonitrile(B) was used as the mobile phase for gradient elution. The flow rate was 0.3 mL·min^-1, the column temperature was 30 ℃, and the sample volume was 5 μL. The electrospray ionization(ESI) was used to collect data in positive and negative ion modes with the scan range m/z of 80-1 200. Compared with the retention time of reference substance, mass spectrometry data, and combing the accurate relative molecular mass, mass spectrometry fragmentation rule, mass spectrometry databases(PubChem, ChemicalBook, etc.) and related literatures, the chemical components of Fraxini Cortex was identified quickly and accurately. RESULTS A total of 72 chemical constituents were identified in this study, including 20 coumarins, 8 iridoids, 10 phenylethanol glycosides, 17 flavonoids, 16 organic acids and 1 other species, in which 19 compounds in positive ion mode and 53 in negative. Thirty-six of them were identified from Fraxini Cortex for the first time. CONCLUSION This study establishes a UPLC-Q-Exactive Orbitrap MS method for the isolation and identification of compounds in Fraxini Cortex, which can comprehensively elucidate the chemical composition. This study will provide a reference for quality control and the material basis of pharmacological effects of Fraxini Cortex.