Iridoid Glycosides and Flavonoids Isolated from the Twigs and Leaves of Callicarpa nudiflora and Their Anti‐Inflammatory Activities

A new iridoid glycoside, named 6'-O-trans-feruloyl-8-epiloganic acid, together with fifteen known compounds were isolated from the twigs and leaves of Callicarpa nudiflora, a traditional Chinese medicine to treat inflammatory-related diseases. Their structures were identified by comprehensive spectroscopic analysis and comparison with reported data. Bioassay results revealed that twelve of the isolates could obviously inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cell lines with IC50 values from 0.64 to 38.72 μM. Among them, compounds 1 (3.27 μM), 6 (5.23 μM), 13 (1.56 μM) and 14 (0.64 μM) exhibited significantly higher activities than that of the positive control (27.13 μM). Additionally, it was supposed that the presence of the carboxy group at the C-4 position of iridoid glycosides and glycosylation at C-3 position of flavonoids might impact their inhibitory activities against NO production.