A New Megastigmane Glycoside and Anti-Inflammatory Bibenzyls from the Stems of Dendrobium henanens

A new megastigmane glycoside, namely (9S)-O-β-D-glucopyranosyl-2,5-megastigmen-4-one (1), along with seven known bibenzyls (2-8) were isolated from the aerial stems of Dendrobium henanense. Their structures were elucidated by spectroscopic and mass-spectrometric analyses, including 1D-, 2D-NMR and HR-MS. The anti-inflammatory activities of compounds 1-8 evaluated its anti-inflammatory activity by inhibiting the production of inflammatory cytokines such as NO, TNF-α and IL-6 in LPS-stimulated RAW264.7 macrophages. Compounds 3, 4, 6-8exhibited moderated anti-inflammatory activity with IC50 values of below 100 µΜ.