New caffeoyl derivatives from Elephantopus scaber

Three new caffeoyl derivatives (1-3), together with two known ones (4-5), were isolated from the whole plant of Elephantopus scaber Linn. The structures of the new compounds were elucidated using detailed spectroscopic analysis. Compound 4 was obtained and its NMR data were given for the first time. All isolates were evaluated for their anti-inflammatory activity against lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and pro-inflammatory cytokines release in RAW 264.7 cells. Compounds 2-5 showed mild inhibitory activities with IC50 values ranging from 64.78 to 87.21 mu M, and 3-4 could inhibit LPS-induced tumor necrosis factor-alpha (TNF-alpha) production.