[Iridoids from stem bark of Syringa pinnatifolia].

One new iridoid, named alashanidoid A, and five known analogues, were isolated from the stem bark of Syringa pinnatifolia by various chromatographic methods. Their structures were determined on the basis of MS and NMR spectroscopic data analyses, and comparison with those in literature. Among them, compounds 3-5 were isolated from this genus for the first time, and 2 and 6 were isolated from the species for the first time.These isolates were tested for their in vitro anti-inflammatory activities against NO production in lipopolysaccharide(LPS)-induced RAW264.7 macrophages in mice and cytotoxicity of HepG2 cell line, however, no obvious activity was observed at the concentration of 40 μmol•L⁻¹.