Objective To rapidly identify the chemical constituents of the ethanol extract of Dendropanax dentiger, a She ethnic medicine, using ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and feature-based molecular networking(FBMN), and preliminarily evaluate its anti-inflammatory activity. Methods Chromatographic separation was performed on an ACQUITY UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 μm) using a gradient elution with 0.1% formic acid in water (A) and acetonitrile (B) as the mobile phases. MS data were acquired in both positive and negative ion modes, and FBMN was constructed on the global natural products social molecular networking (GNPS) platform (http://gnps.ucsd.edu). Based on the matching results of the SIRIUS 6.2.2 software and the GNPS database, combined with the reference standards, retention time, feature fragments, literature, and information from the PubChem and MassBank databases, and in combination with the structural clustering characteristics of FBMN, the chemical composition of the alcohol extract of D. dentiger was rapidly identified and its lysis rules were summarized. In vitro anti-inflammatory effects were evaluated using a lipopolysaccharide (LPS)-induced RAW264.7 macrophage inflammation model, with CCK-8, Western blotting, and immunofluorescence analyses. Results A total of 59 compounds were identified, including 18 phenolic acids, 11 lignans, eight flavonoids and flavonoid glycosides, six coumarins, four cyclic peptides, three phenylethanoid glycosides, four fatty acids and derivatives, two iridoids, two glycosides, and one alkaloid. Among them, 19 potentially unreported compounds were identified from D. dentiger for the first time. Three positional isomers—isochlorogenic acid A, B, and C were successfully identified via FBMN, and a methylated derivative was further proposed. The results of cell experiments demonstrated that the ethanol extract of D. dentiger significantly suppressed LPS-induced inflammatory responses in RAW264.7 cells by downregulating interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) expression, upregulating IL-10 secretion, and inhibiting nuclear translocation of nuclear factor-kappa-B p65(NF-κB p65) . Conclusion FBMN effectively overcomes the limitations of traditional molecular networking in isomer identification. The integration of UPLC-Q-TOF-MS/MS with FBMN enables rapid and efficient identification of the complex components in D. dentiger, leading to the first identification of 19 potentially unreported compounds. The ethanol extract of D. dentiger exhibits promising anti-inflammatory activity, providing an experimental basis for further research and development application of its active substances.

Dendropanax dentiger (Harms) Merr.  /  UPLC-Q-TOF-MS/MS  /  feature-based molecular networking  /  isochlorogenic acid A  /  isochlorogenic acid B  /  isochlorogenic acid C  /  anti-inflammatory activity