Scavenging effects of tea catechins and their derivatives on 1,1-diphenyl-2-picrylhydrazyl radical

摘要: The scavenging effects of tea catechins and their epimerized, acylated, glucostylated derivatives on 1,1-diphenyl-2-picrythydrazyl (DPPH) radical were evaluated by electron spin resonance spectrometry. Tea epimers shown to have 50% ability in the concentration range 1 3 microM. No significant differences observed between activities epimers, and, hence, are not dependent sterical structure. relationship structure was also examined with acylated glucosylated catechin derivatives. It is suggested that galloyl moiety attached flavan-3-ol at position has a strong DPPH as well ortho-trihydroxyl group B ring, which elevates efficiency above ortho-dihydroxyl group; been recognized other flavonoids such flavones. results obtained from reactivity different pHs suggest only contribute maintaining more effectively wide conditions acidic alkaline, but ortho-dihydroxyls ring limited neutral alkaline regions. difference abilities trihydroxyls (probably moiety) dihydroxyls can be explained terms redox potentials. concluded skeleton most important structural features for displaying an excellent radical.