Comparative Study on the Antioxidative Effects and α-Glucosidase Inhibitory Potential In Vitro among Ellagic Acid and Its Metabolites Urolithins
Zhao‐Rong Li, Rui‐Bo Jia, Yurong Mo, H. Wang, Donghui Luo, Chunxia Zhou, Mouming Zhao
Abstract
The current study compared the radical scavenging and α-glucosidase inhibition potentials of ellagic acid (EA) and its metabolites, urolithins (Uros), and further explored the structure-activity relationship. The outcomes indicated that urolithin M5 (Uro-M5), EA, and urolithin M6 (Uro-M6) exhibited superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity; EA and urolithin D (Uro-D) expressed better ABTS scavenging ability, and EA and Uro-M5 showed preferable α-glucosidase inhibition activity. The results of CD spectra and fluorescence spectral analysis explained the interaction between Uros and α-glucosidase. Correlation analysis indicated that hydroxyl groups were crucial for the antioxidative effect, while C-8 OH contributed greatly to the α-glucosidase inhibition activity. Quantum mechanical analysis showed that both EA and Uros exhibited strong electrophilic properties. These comparative results showed a biological discrepancy between Uros and provided essential information for exploring the bioactive application of EA as a functional ingredient or dietary supplement.