Phenazine radicals: O‐benzoquinone isoindoline derivatives were condensed with aromatic 1,2‐diamines, followed by oxidation to give phenazine‐di‐N‐oxide isoindoline nitroxides. One derivative showed high binding affinity and selectivity towards abasic sites in duplex DNA when the orphan base was cytosine; all of the derivatives showed negligible binding to abasic sites in RNA.

中文翻译：

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一氧化氮衍生的N-氧化物吩嗪类化合物对DNA的非共价自旋标记。

吩嗪基：将O-苯醌异吲哚啉衍生物与芳香族1,2-二胺缩合，然后氧化得到吩嗪二N-氧化异吲哚啉氮氧化物。当孤儿碱基为胞嘧啶时，一种衍生物对双链DNA中的无碱基位点显示出高结合亲和力和选择性。所有的衍生物与RNA的无碱基位点的结合都可忽略不计。