Analysis of Natural Antioxidants Using Electron Paramagnetic Resonance (EPR) Spectroscopy

Electron Paramagnetic Resonance (EPR), also known as Electron Spin Resonance (ESR), is a modern spectroscopic technique that is used for the analysis of materials with unpaired electrons. EPR spectroscopy, focusing on electron spins, uses magnetic fields and microwaves to obtain chemical and structural information about the environment around an unpaired electron, providing detailed information on the structure and bonding of paramagnetic species. This spectroscopic technique has been used in the study of natural products, especially for evaluating free-radical-scavenging properties. EPR spectroscopy is expected to continue providing unique and complementary information about natural products, enhancing insights into their chemical properties, biological activities, and potential therapeutic applications. This review article critically evaluates recently published literature on the application of EPR in the assessment of antioxidant properties of various natural products, by retrieving relevant information from online databases, e.g., Google Scholar, Web of Science and PubMed.