Conferols A and B, new anti-inflammatory 4-hydroxyisoflavones from Caragana conferta

Conferols A (1) and B (2), the new 4-hydroxyisoflavones, have been isolated from the dichloromethane sub-fraction of the methanolic extract of Caragana conferta along with 3',5'-dihydroxy, 7,4'-dimethoxyisoflavone (3), E-cinnamic acid (4), tetracosyl 3,4-dihydroxy-E-cinnamate (5), docosyl 3,4-dihydroxy-E-cinnamate (6), beta-sitosterol (7), beta-sitostrerol 3-O-beta-D-glucopyranoside (8), stigmasterol (9) and lupeol (10), respectively, reported for the first time from this species. The structures of the new compounds were elucidated through spectroscopic techniques including MS and 2D-NMR. The compounds 1-3 showed significant anti-inflammatory activity in the respiratory burst assay.