Natural and Synthetic Chalcones as Privileged Molecules with Antioxidant Activities

Increased concentrations of reactive oxygen species (ROS) cause cell degradation and distortion of molecules with protein, lipid nature or macromolecules. Maintaining a balance between ROS formated and eliminated is directly correlated with maintaining cell homeostasis. Antioxidants are molecules that have ability to counteract negative effects of ROS. These are synthetic and natural compounds. A class of compounds highly studied for antioxidant properties are flavonoids. From these, chalcones are privileged molecules due to numerous biological properties they have, many of them being dependent on their antioxidant capacity. This property is dependent on the nature and position of the substituents on the two aromatic subunits (aldehyde and acetofenone), hydroxy and methoxy groups being essential. Also, by replacing an aromatic subunit with a heterocycle (e.g., isoxazole), hybrid molecules with superior antioxidant properties are formed.