Structures and Anti-Inflammatory Evaluation of Phenylpropanoid Derivatives from the Aerial Parts of Dioscorea polystachya .

Seven undescribed phenylpropanoid constituents, including three new bibenzyl derivatives ( 1 - 3 ) along with four new benzofuran stilbene derivatives ( 4 - 7 ), were isolated from the aerial parts of Dioscorea polystachya . The structures of these compounds were elucidated using a combination of spectroscopic analyses, including UV, IR, HRESIMS, 1D, and 2D NMR. Further, all the compounds were evaluated on the anti-inflammatory activity for their inhibition of nitric oxide (NO) production by RAW 264.7 macrophages cells, and some of them ( 1 - 3 and 6 ) displayed inhibitory activity with IC ₅₀ values in the range of 9.3-32.3 μM. Moreover, compound 3 decreased the expression of iNOS in Western blot analysis, suggesting compound 3 is mediated via the suppression of an LPS-induced NF-κB inflammasome pathway.