Three new secoiridoid glycosides from the rhizomes and roots of Gentiana scabra and their anti-inflammatory activities

Three new (1-3) and 17 known (4-20) iridoid and secoiridoid glycosides were isolated from a methanol extract of the rhizomes and roots of Gentiana scabra. Their chemical structures were elucidated from 1D and 2D NMR, IR absorption, and HR-ESI-MS spectra, as well as comparisons of these data with reported values. The effects of the isolated compounds on lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells were investigated. Compounds 6, 10 and 20 exhibited significant inhibitory effects on LPS-induced IL-12 p40 and IL-6 production with IC50 values of 1.62-14.29 mu M. Compound 10 also showed a strong inhibitory effect on the LPS-stimulated production of TNF-alpha with an IC50 value of 10.45 mu M.