ANTIOXIDANT PROFILE OF MONOHYDROXYLATED AND DIHYDROXYLATED FLAVONE DERIVATIVES IN FREE-RADICAL GENERATING SYSTEMS

A number of free radical generating systems were used to investigate t he antioxidant properties and structure-activity relationships of a se ries of monohydroxylated and dihydroxylated flavones. Ortho-dihydroxyl ated flavones showed the highest inhibitory activity on enzymic and no n-enzymic microsomal lipid peroxidation as well as on peroxyl radical scavenging. Most flavones were weak scavengers of hydroxyl radical, wh ile ortho-dihydroxylated flavones interacted with superoxide anion gen erated by an enzymic system or by human neutrophils. This series of co mpounds did not exert cytotoxic effects on these cells. Scavenging of superoxide and peroxyl radicals may determine the antioxidant properti es of these active flavones.