| Abstract: | A method to assess anti‐oxidant activity quantitatively is presented. In this method, free radicals (OH·) were produced from the Fenton reaction. Electron spin resonance spectroscopy (ESR) was then used to determine the effectiveness of five anti‐oxidants to scavenge the free radicals. Anti‐oxidant activity was assessed as the percentage reduction of the ESR signal intensity relative to that of a control after 10 min. The order of the potency of the antioxidants at 4.8 mM was: caffeic acid > o‐coumarin > 6,7‐dihydroxy‐4‐methylcoumarin > catechin > scopoletin. In addition, pro‐oxidant activity (a higher ESR signal intensity than that of the control) was observed for catechin and scopoletin at low concentrations (below 3.6 mM ). © 2000 Society of Chemical Industry |
