9,10-Dihydrophenanthrene derivatives and one 1,4-anthraquinone firstly isolated from Dioscorea zingiberensis C. H. Wright and their biological activities.

Two new phenanthrene derivatives, 2,5,7-trimethoxy-9,10-dihydrophenanthrene-1,4-dione (1) and 2,5,6-trihydroxy-3,4-dimethoxy-9,10-dihydrophenanthrene (3), one new anthracenedione, 2,5,7-trimethoxyanthracene-1,4-dione (2), together with two known 9,10-dihydrophenanthrenes (4-5) were isolated from the rhizomes of Dioscorea zingiberensis C. H. Wright. The structures of these new compounds were established based on extensive NMR spectroscopy. Several isolated compounds were evaluated for the inhibition against nitric oxide (NO) production in the lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cell line, DPPH radical scavenging, and inhibitory activity on Free Fatty Acids (FFAs) induced triglyceride accumulation in HepG2 cells. Compound 2 exhibited moderate anti-inflammatory activity, compound 3 possessed comparable DPPH radical scavenging activity as Vitamin C, compounds 2 and 4 showed potent inhibitory activities on triglyceride accumulation.