Isolation of a new natural kingiside aglucone derivative and other anti-inflammatory constituents from Syringa reticulata.

A new secoiridoid, (1R,5S,8S,9R)-1-methyl-kingiside aglucone (1), along with nine known compounds (2-10), were isolated from the ethanol extract of the stem bark of Syringa reticulata (Bl.) Hara. The structure of compound 1 was elucidated using HR-ESI-MS, 1D and 2D NMR spectroscopy. Compounds 1-10 were evaluated for their inhibitory activity against NO, TNF-α and IL-6 production. Compounds 1, 3, 5 and 7-10 significantly inhibited the levels of NO, TNF-α and IL-6 in LPS-induced RAW264.7 cells from concentrations of 3 to 30 μM.