Anti-inflammatory homoisoflavonoids from the tuberous roots of Ophiopogon japonicus

Two new homoisoflavonoids, named ophiopogonone E (1) and ophiopogonanone H (2), together with thirteen known ones (3-15) were isolated from the tuberous roots of Ophiopogon japonicus. Their structures were elucidated by spectroscopic and chemical analyses. Compounds 7 and 15 were isolated from the genus for the first time. In addition, compounds 2-15 were evaluated for their effects on the inhibition of NO production induced by lipopolysaccharide in the murine microglial cell line BV-2. Compounds 2, 4, 6, 7, 10, 11 showed potent inhibitory effects on NO production with IC(50) values of 20.1, 17.0, 7.8, 5.1, 19.2 and 14.4 μM respectively.