COX-2 inhibitory activity of homoisoflavanones and xanthones from the bulbs of the Southern African Ledebouria socialis and Ledebouria ovatifolia (Hyacinthaceae: Hyacinthoideae)

Homoisoflavonoids, including (E)-3-(3′,4′-dihydroxybenzylidene)-5-acetoxy-7-hydroxychroman-4-one (ovatifolionone acetate) and (E)-3-(3′,4′-dihydroxybenzylidene)-7-hydroxy-5-methoxychroman-4-one, showed selective COX-2 inhibition.