茶多酚类化合物的单电子还原电位

One-electron Reduction Potentials of Tea Polyphenolic Compounds

单电子还原电位是辐射保护和敏化中“电荷转移”的根本判据，此文采用时间分辨脉冲电子辐解瞬态吸收光谱装置，在PH＝7．0的磷酸缓冲溶液中，以杜醌（－244mV）为参比，准确地测定了四种茶多酚类衍生物EGCG、GCG、GC、C的单电子还原电位值分别为－316，－325，－328，－326mV；并通过与DNA碱基胸腺嘧啶的单电子还原电位（－1100mV）作比较，从热力学角度初步评价了这类化合物对DNA碱基的辐射损伤均有良好的保护作用．

One-electron reduction potentials could be use as the critical-criteria of charge transfer protect and sensitization. The One-electron reduction potentials of four Tea Polyphenol derivatives using duroquinone as the reference compound have been measured with the technique of pulse radiolysis, the one-electron reduction potentials of EGCG, GCG, GC, C are-316, -325, -328,-326mV, respectively. Acccording to the criteria of charge transfer of protection and sensitization,compared with one-electron reduction potential of thymine (-1100mV), EGCG, GCG, GC and Ccan be used to protect efficiently the target molecule thymine from the damage induced by electron addition.