In the title compound, 2-(3-furyl)-1,4,6,6a,7,10,10a,10b-octahydro-6a,10b-dimethyl-2H-naphtho[2,1-c]pyran-7,4-dione, C19H20O4, one of the fused cyclohexane rings adopts a half-chair conformation and the other a sofa conformation. The conformation of the pyran ring is intermediate between sofa and half-chair. Screw-related molecules along the c axis form an infinite one-dimensional chain.
their structures were determined by extensive spectroscopic analyses, chemical reactions and computer-assisted calculations. The inhibitory activity of the isolated compounds and their chemical derivatives on nitric oxide production in lipopolysaccharide and interferon-γ activited J774.1 macrophage-like cells was also evaluated.