Flavonoids are common plant natural products able to suppress ROS-related damage and alleviate oxidative stress. One of key mechanisms, involved in this phenomenon is chelation of transition metal ions. From a physiological perspective, iron is the most significant transition metal, because of its abundance in living organisms and ubiquitous involvement in redox processes. The chemical, pharmaceutical, and biological properties of flavonoids can be significantly affected by their interaction with transition metal ions, mainly iron. In this review, we explain the interaction of various flavonoid structures with Fe(II) and Fe(III) ions and critically discuss the influence of chelated ions on the flavonoid biochemical properties. In addition, specific biological effects of their iron metallocomplexes, such as the inhibition of iron-containing enzymes, have been included in this review.

BIOCEV 1st Faculty of Medicine Charles University Prague CZ 252 50 Vestec Czech Republic

Department of Analytical Chemistry Faculty of Chemical Engineering University of Chemistry and Technology CZ 166 28 Prague Czech Republic

Department of Paediatrics and Inherited Metabolic Disorders 1st Faculty of Medicine Charles University and General University Hospital Prague CZ 121 08 Prague Czech Republic

Department of Pathological Physiology Faculty of Medicine Masaryk University Kamenice 5 625 00 Brno Czech Republic

Department of Pharmaceutical Biochemistry Wroclaw Medical University Borowska 211A 50556 Wroclaw Poland

Department of Pharmaceutical Biology and Botany Wroclaw Medical University Borowska 211 50556 Wroclaw Poland

Department of Physiology Faculty of Medicine Masaryk University Kamenice 5 625 00 Brno Czech Republic

Department of Urology St Anne's University Hospital Brno Pekařská 53 656 91 Brno Czech Republic

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