Villosarins A and B, Anti‐Inflammatory Meroterpenoids From the Marine Sponge Dysidea Villosa

Two undescribed sesequiterpene hydroquinone meroterpenoids, villosarins A (1) and B (2), together with eight known analogues (3-10), were isolated from the marine sponge Dysidea villosa collected from the South China Sea. The structures of 1 and 2 were elucidated by a combination analysis of HRESIMS, 1D and 2D NMR spectra, and their absolute configurations were determined by electronic circular dichroism (ECD) calculations. Villosarins A and B featured two unusual hydroquinone units modified by furan-2,5-diones. Among the 10 isolates, compounds 1, 2, 7-10 were evaluated for inhibitory activity on the production of inflammatory cytokines, interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in lipopolysaccharide (LPS)-stimulated RAW 264.7 mouse macrophages. Villosarins A (1) and B (2) showed potent inhibitory activity on the production of IL-6, IL-1β, and TNF-α in a dose-dependent manner.