Chemical Constituents of the Endophytic Fungus Penicillium steckii HJT-A-10 from Rhodiola tibetica and Their Anti-Inflammatory Activities

Chemical examination of Penicillium steckii HJT-A-10, an endophytic fungus derived from Rhodiola tibetica, led to the isolation of ten metabolites. Structural elucidation by spectroscopic methods revealed that two of these were previously unreported compounds (1 and 2), though the absolute stereochemistry of 2 remained provisional; the other eight isolates (3–10) were identified as known compounds. All ten metabolites were tested for their capacity to inhibit nitric oxide (NO) production in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). Compounds 1–4 and 7–10 exhibited marked inhibitory effects. Among the two new compounds, 2 displayed stronger activity, with an IC50 value of 19.01 µM. To explore the potential mechanisms of action, network pharmacology and molecular docking analyses were subsequently conducted to predict the relevant targets and signaling pathways.