Anti-inflammatory anthraquinones from the crinoid Himerometra magnipinna

Chemical investigation of a crinoid Himerometra magnipinna has afforded three anthraquinones (1-3), including one new metabolite, (+)-rhodoptilometrin (1). The structures of these compounds were elucidated on the basis of their spectroscopic data and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. In the in vitro anti-inflammatory effects test, compound 2 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS protein of the LPS-stimulated RAW264.7 macrophage cells.