Five meroterpenoids, rhodonoids K-M (1-2), daurichromene E (3), and grifolins A-B (4-5), together with seven known compounds (6-12), were isolated from Rhododendron anthopogonoides. The chemical structures of these compounds were elucidated through comprehensive analysis of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), ultraviolet (UV), infrared spectroscopy (IR), and nuclear magnetic resonance (NMR) data. Their absolute configurations were determined by comparing experimental electronic circular dichroism (ECD) spectra with computed values. Notably, compounds 1 and 3 demonstrated significant inhibitory effects on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells. These compounds markedly suppressed the mRNA expressions of inflammatory factors, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) while also down-regulating the protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2).
Mice ; Rhododendron/chemistry* ; Animals ; Anti-Inflammatory Agents/isolation & purification* ; RAW 264.7 Cells ; Terpenes/isolation & purification* ; Molecular Structure ; Tumor Necrosis Factor-alpha/immunology* ; Cyclooxygenase 2/immunology* ; Nitric Oxide Synthase Type II/immunology* ; Macrophages/immunology* ; Interleukin-6/immunology* ; Lipopolysaccharides ; Interleukin-1beta/immunology*