Bioactive prenylated c₆-c₃ derivatives from the roots of Illicium brevistylum

Three new prenylated C₆-C₃ compounds (1-3), together with two known prenylated C₆-C₃ compounds (4-5) and one known C₆-C₃ derivative (6), were isolated from the roots of Illicium brevistylum A. C. Smith. The structures of 1-3 were elucidated by spectroscopic methods including 1D and 2D NMR, HRESIMS, CD experiments and ECD calculations. The structure of illibrefunone A (1) was confirmed by single-crystal X-ray diffraction analysis. All compounds were evaluated in terms of their anti-inflammatory potential on nitric oxide (NO) generation in lipopolysaccharide-stimulated murine RAW264.7 macrophages and murine BV2 microglial cells, antiviral activity against Coxsackievirus B3 (CVB3) and influenza virus A/Hanfang/359/95 (H3N2). Compounds 3 and 4 exhibited potent inhibitory effects on the production of NO in RAW 264.7 cells with IC₅₀ values of 20.57 and 12.87 μM respectively, which were greater than those of dexamethasone (positive control). Compounds 1 and 4-6 exhibited weak activity against Coxsackievirus B3, with IC₅₀ values ranging from 25.87 to 33.33 μM.