EPR Analysis of Antioxidant Compounds

Abstract

A free radical is a molecular species having an unpaired electron and it is a highly reactive entity and unstable. A free radical is a molecule with one or more unpaired electrons in its outer shell. Free radicals can be formed by chemical bond breakage from molecules or by redox reactions. When cells use oxygen, the oxidative stress occurs. The oxidative stress causes free radical formation. Free radicals can also be generated from ionizing radiations, ozone, heavy metal poisoning, cigarette smoking, and chronic alcohol intake. These free radicals are highly reactive and oxidize biomolecules leading to tissue injury and cell death. They also cause toxic effects and diseases. Antioxidants neutralize free radicals resulting from oxidative stress. Antioxidants play an important role in the treatment of diseases. The most suitable method for the analysis of free radicals is the electron para- magnetic resonance (EPR) spectroscopy method. The EPR method detects a paramagnetic center with a single electron. It gives information about the interactions with other nuclei around one electron. It provides information on the structure and environment of radicals.