ESR study on the structure–antioxidant activity relationship of tea catechins and their epimers

• Published in: Biochimica et biophysica acta Vol. 1427; no. 1; pp. 13 - 23
• Main Authors: Guo, Qiong, Zhao, Baolu, Shen, Shengrong, Hou, Jingwu, Hu, Jungai, Xin, Wenjuan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 14.03.1999
• Subjects: Amidines; Amidines - chemistry; analogs & derivatives; antioxidants; Antioxidants - chemistry; Bepridil; Bepridil - analogs & derivatives; Bepridil - chemistry; Biphenyl Compounds; Catechin; Catechin - analogs & derivatives; Chemical structure; chemistry; Electron spin resonance; Electron Spin Resonance Spectroscopy; Epimer; flavonols; Free Radical Scavengers; Free Radical Scavengers - chemistry; Gallate group; Isomerism; Oxidation-Reduction; Oxygen; Oxygen - chemistry; Picrates; Scavenging activity; Singlet Oxygen; Structure-Activity Relationship; structure-activity relationships; Superoxides; Superoxides - chemistry; tea; Tea - chemistry; Tea catechin; EGC, (−)-epigallocatechin; EC, (−)-epicatechin; Electron spin resonance; TEMPONE, 2,2,6,6-tetramethyl-4-piperidone; Epimer; Chemical structure; DMPO, 5,5-dimethyl-1-pyrroline-1-oxide; TC, tea catechin; GC, (−)-gallocatechin; (+)-C, (+)-catechin; Tea catechin; GCG, (−)-gallocatechin gallate; ESR, electron spin resonance; Gallate group; Scavenging activity; 4-POBN, α-(4-pyridyl-1-oxide)- N- t-butylnitrone; EGCG, (−)-epigallocatechin gallate; DPPH, 1,1-diphenyl-2-picrylhydrazyl; AAPH, 2,2′-azobis(2-amidinopropane)hydrochloride

The purpose of this study is to examine the relationship between the free radical scavenging activities and the chemical structures of tea catechins ((−)-epigallocatechin gallate (EGCG), (−)-epigallocatechin (EGC) and (−)-epicatechin (EC)) and their corresponding epimers ((−)-gallocatechin gallate (...