A new angular naphthopyrone from feather star Comanthus parvicirrus (Müller, 1841)

A chemical investigation was carried out on a feather star Comanthus parvicirrus collected from the waters of Southern Taiwan, which led to the isolation of three angular naphthopyrones (1–3), including one new metabolite, 8‑hydroxy-5,6,9,10-tetramethoxy-2-methyl-4H-benzo[h]chromen-4-one (1). The structures of compounds 1–3 were assigned based on spectroscopic methods, including UV, MS, 1D- and 2D-NMR spectra, and the structure of 1 was established by single-crystal X-ray diffraction analysis directly. The compound 3 were found to exhibit significant anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophages through attenuating the expression of the inducible nitric oxide synthase (iNOS) proteins.