Host-associated differences in chemical composition and antioxidant activity of Phellinus igniarius

The chemical composition and antioxidant profile of Phellinus igniarius from different host-associated sources were investigated using an integrated strategy combining polyhedral mass defect filtering, targeted quantification, chemometric analysis, and in vitro antioxidant assays. A total of 72 compounds, including flavonoids, phenolics, organic acids, terpenoids, and other constituents, were annotated by UHPLC-Q-TOF-MS/MS. Fourteen representative constituents were further quantified by HPLC-QQQ-MS/MS. PCA and OPLS-DA showed chemical differentiation between poplar-associated and mulberry-associated samples, although these patterns should be interpreted in the context of field-collected materials. DPPH and ABTS assays indicated that mulberry-associated samples generally exhibited stronger radical-scavenging activity. IC 50 based grey relational analysis further highlighted caffeic acid, hispolon, hispidin, phenylalanine, and osmundacetone as candidate antioxidant-associated markers. These results provide a chemical and antioxidant-activity reference for the quality evaluation of P. igniarius .