Comparison of Free Radical Scavenging Abilities of Various Chalcone Antioxidants

Free radicals are highly reactive chemical species found in cells; various reactive oxygen species (ROS) are produced as a result of normal cell metabolism, air pollution, smoking, UV radiation, and inflammation. Oxidative stress may be the cause of many neurodegenerative and cardiovascular diseases, and continued oxidative stress in cells leads to loss of cell membrane integrity, DNA damage, and apoptosis. Chalcone antioxidants, found in plants and foods, stabilize ROS. Chalcones have antifungal, anti‐inflammatory, antimalarial, antitumor, and antiviral activities. The present study concerns relative efficacies of various hydroxylated chalcones in comparison with one another and with synthetic antioxidants. Free radical scavenging abilities of seven hydroxylated chalcones were analyzed using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assays. Triplicate results confirmed previous results by our group that chalcones with 5′‐hydroxyl groups performed significantly better. Synthetic chalcones performed with less efficacy than natural chalcones. Butylated hydroxytoluene (BHT), a synthetic antioxidant found in processed foods, was used as a standard and had the least efficacy. In addition, the analysis of single crystal X‐ray studies on these chalcones solidifies the role of intermolecular interactions of hydroxyl groups in antioxidant activity. Supported by HHMI 52006322 and VC URSI 2012.