IRON CHELATION BY CHLOROGENIC ACID AS A NATURAL ANTIOXIDANT

Chlorogenic acid, a dietary antioxidant, effectively inhibited the iro n-induced lipid peroxidation of bovine liver microsomes in a concentra tion-dependent manner. In the Fenton-type reaction, chlorogenic acid i nhibited the production of the hydroxyl radical by iron-EDTA or iron-A DP, while iron plus chlorogenic acid did not generate the hydroxyl rad ical. The formation of an iron complex with chlorogenic acid was demon strated by UV/vis absorbance spectroscopic, ESR and H-1-NMR studies. T he ferric complex with chlorogenic acid was in the ferric high-spin st ate near rhombicity, and had no radical scavenging activity. The resul ts indicate that chlorogenic acid prevented the formation of the hydro xyl radical by forming a chelate with iron whose complex cannot cataly ze the Fenton-type reaction.