Antioxidant properties of nitrocaffeic acids

A series of nitrodihydroxybenzenes and nitrocaffeic acids were prepared and their hydroxyl radical (OH°) and superoxide anion (O2−) scavenging activities and xanthine oxidase inhibition activities were evaluated. 2-Nitrocaffeic acid is the more potent O2− scavenger. 2- (and 5)-Nitrocaffeic acids are the more potent xanthine oxidase inhibitors.