A new anti-inflammatory chromone from the leaves of Eucalyptus viminalis

A new 5,7-dihydroxychromone compound (1) was isolated from the leaf extract of Eucalyptus viminalis (Myrtaceae), along with two known compounds (2 and 3). Their structures were elucidated on the basis of mass and NMR spectroscopic data analysis. Compound 1 showed moderate anti-inflammatory activity by down-regulating nitric oxide in LPS (Lipopolysaccharide) and IFN-γ (Interferon gamma) treated RAW 264.7 macrophages and N-11 microglial cells with an IC ₅₀ value for nitric oxide downregulation of 44.0 ± 9.0 μg/mL and 43.4 ± 7.3 μg/mL respectively. Compound 1 was non-toxic to RAW macrophage and N-11 microglial cells (>36 μg/mL).