The antioxidant activity of phloretin: the disclosure of a new antioxidant pharmacophore in flavonoids

The antioxidant activity of phloretin: the disclosure of a new antioxidant pharmacophore in flavonoids.Rezk BM, Haenen GR, van der Vijgh WJ, Bast A.Department of Pharmacology and Toxicology, Faculty of Medicine, Universiteit Maastricht P.O. Box 616, 6200 MD Maastricht, The Netherlands.Phloretin is a dihydrochalcone flavonoid that displays a potent antioxidant activity in peroxynitrite scavenging and the inhibition of lipid peroxidation. Comparison with structurally related compounds revealed that the antioxidant pharmacophore of phloretin is 2,6-dihydroxyacetophenone. The potent activity of 2,6-dihydroxyacetophenone is due to stabilisation of its radical via tautomerisation. The antioxidant pharmacophore in the dihydrochalcone phloretin, i.e., the 2,6-dihydroxyacetophenone group, is different from the antioxidant pharmacophores previously reported in flavonoids. (c) 2002 Elsevier Science (USA).