Phenanthrenoids from Juncus acutus L., new natural lipopolysaccharide-inducible nitric oxide synthase inhibitors.

The novel natural product juncutol (1), 1,4,7-trimethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene-2,6-diol, along with the three related metabolites juncusol (2), dehydrojuncusol (3), and 6-hydroxymethyl-1-methyl-5-vinyl-9,10-dihydrophenanthrene-2-ol (4), were isolated from the rhizomes of Juncus acutus L. (Juncaceae) growing in Egypt. The structural identity of 1 was determined on the basis of spectroscopic analyses, including 2D NMR spectroscopy.