Anthraquinone-Sensitized Photooxidation of 5-Methylcytosine in DNA Leading to Piperidine-Induced Efficient Strand Cleavage
作者:Hisatsugu Yamada、Yuya Kitauchi、Kazuhito Tanabe、Takeo Ito、Sei-ichi Nishimoto
DOI:10.1002/chem.201001884
日期:2011.2.11
key elementary reaction in the photooxidative strand cleavage at the mC site. Incorporation of an AQ sensitizer into the interior of a strand of the duplex enhanced the one‐electron photooxidation of mC, presumably because of an increased intersystem crossing efficiency that may lead to efficient piperidine‐induced strand cleavage at an mC site in a DNA duplex.
通过蒽醌(AQ)衍生物的敏化作用,研究了5-甲基-2'-脱氧胞苷(d m C)和5-三甲基叔甲基-2-2'-脱氧胞苷([D 3 ] d m C)的单电子光氧化作用。含有d m C和蒽醌2-磺酸盐(AQS)的充气水溶液的光辐照可产生高产率的5-甲酰基-2'-脱氧胞苷(d f C)和5-羟甲基-2'-脱氧胞苷(d hm C)。初始的单电子氧化过程。关于d的AQS-光敏氧化氘同位素效应米Ç表明,在d的光敏氧化速率决定步骤米C涉及ad m C-四氧化物中间产物的C5-氢原子的内部转移,从而产生d f C和d hmC。对于包含5-甲基胞嘧啶(m C)的双链DNA与AQ发色团结合在一起的情况m C进入DNA链的主链以便固定在特定位置,通过光激发AQ对m C进行有效的直接单电子氧化,从而导致目标m处的唯一DNA链断裂热哌啶处理后的C位。根据在类似的AQ光敏化中观察到的抑制5-triuteruterio-