Nudifloids W‐Y, Three New 3,4‐<i>Seco</i>‐Labdane Diterpenoids With Anti‐Inflammatory Activity From <i>Callicarpa nudiflora</i>

Three new seco-labdane diterpenoids, named nudifloids W-Y (1-3), along with twelve known diterpenoids (4-15) and one sesquiterpenoid (16) were isolated from the stems and leaves of Callicarpa nudiflora. The chemical structures of compounds 1-3 were determined by one-dimensional (1D) and 2D nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, and electronic circular dichroism. The chemical structures of the remaining 13 known compounds were determined by comparing their spectral data with those reported in the literature. All compounds were screened for anti-inflammatory activity by analyzing the detection of lactate dehydrogenase release in J771A.1 cell, among which compound 3 showed moderate activity with a half-maximal inhibitory concentration value of 2.10 ± 0.21 µM demonstrating that compound 3 inhibited lipopolysaccharide and nigericin-induced pyroptosis in J774A.1 cells in a dose-dependent manner.