Iridoid glycoside dimers from fruits of Cornus officinalis and their anti-inflammatory activity

A bioassay-guided phytochemical study of the fruits of <i>Cornus officinalis</i> led to the isolation of six new iridoid glycoside dimers, named corndiridoside A-F (<b>1-6</b>), along with 11 analogs (<b>7-17</b>). The structure of these dimers was elucidated using HRESIMS, 1D and 2D NMR, IR, and UV spectra, as well as literature comparisons. The anti-inflammatory activity of all compounds was evaluated, revealing a significant inhibitory effect on all dimers on the production of NO in LPS-stimulated RAW 264.7 cells at concentrations of 25 and 50 μM. Of the six, compounds <b>2</b> and <b>3</b> showed the strongest anti-inflammatory activity.