Sesquiterpene lactones from Seriphidium transiliense and their anti-inflammation activity

Six undescribed sesquiterpene lactones (1-6) and fifteen known compounds (7-21) were isolated from Seriphidium transiliense. The chemical structures were determined by extensive NMR spectroscopic data, HRESIMS, ECD and X-ray diffraction. Among the known compounds, twelve known compounds were isolated for the first time from this plant, including taurine (9), 11-epitaurin (10), α-santonin (11), artesin (13), 11-epiartesin (14), 1α-hydroxy-3β-acetoxyeudesm-4-en-6β, 7α, 11βH-12, 6-olide (15), 1α-hydroxy-3β-acetoxyeudesm-4-en-6β, 7α, 11αH-12, 6-olide (16), artegallin (17), 8α-hydroxytaurin (18), 8α-acetoxytaurine (19), methyl-4α-hydroxy-11(13)-eudesmen-12-oatesaniculamoid D (20), and saniculamoid D (21). The absolute configuration of 2 was determined by X-ray. The X-ray crystal structures of 15 and 16 were reported for the first time. At a concentration of 20 μM, all compounds (1-21) showed significant inhibition of NO production in LPS- stimulated BV2 cells. Among them, compounds 3 and 4 inhibited NO release with IC₅₀ values of 19.30 and 22.05 μM, respectively. Based on the present results, these compounds may be potential anti-inflammatory agents.