New Hirsutinolide-Type Sesquiterpenoids from Vernonia cinerea Inhibit Nitric Oxide Production in LPS-Stimulated RAW264.7 Cells

摘要

Phytochemical investigation of ethanol extracts from two Taiwanese collections of Vernonia cinerea resulted in the isolation of eighteen hirsutinolide-type sesquiterpenoids, including seven new ones designated as vernolides E-K (1-7). All structures were determined by a combination of detailed spectroscopic analyses (NMR and MS) and comparison with reported data. In an in vitro anti-inflammatory assay, compounds 3, 7, 9, 11, and 14 exhibited strong inhibitory activities toward NO production by LPS-induced RAW264.7 macrophages, with IC50 values of 1.18, 0.85, 0.66, 0.71 and 0.45 mu M, respectively, without affecting cellular viability at 40 mu M. Preliminary structure-activity relationships indicate that the ester groups at C-8 and C-13 may enhance inhibition of NO production.