Analysis of the Chemical Composition of Inula hookeri f. major Ling Combining UHPLC-Q-Exactive-Orbitrap MS with Feature-Based Molecular Networking and SIRIUS.

For the evaluation of the chemical composition of Inula hookeri f. major Ling, ultra-high-performance liquid chromatography quadrupole-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive-Orbitrap MS) was integrated with feature-based molecular networking (FBMN) and SIRIUS. The chromatographic separation of the chemical components from Inula hookeri f. major Ling was conducted on a Hypersil GOLD™ aQ C18 (100 mm × 2.1 mm, 1.9 μm) using gradient elution, with a 0.1% formic acid aqueous solution and acetonitrile as the mobile phase. Mass spectrometric analysis was performed in both positive and negative ion modes using an electrospray ionization (ESI) source. Based on the obtained high-resolution fragment ions, FBMN was conducted to enable the clustering and visualization of structurally similar compounds. Molecular formulas were predicted and MS/MS fragment ions were interpreted with the assistance of SIRIUS. A total of 162 compounds were tentatively annotated from Inula hookeri f. major Ling, including terpenoids, phenylpropanoids, fatty acids, organic acids, and other types of compounds. The application of the strategy incorporating UHPLC-Q-Exactive-Orbitrap MS, FBMN, and SIRIUS enables the systematic characterization of the chemical composition of Inula hookeri f. major Ling.