Molecular Design of a New Class of Spin-Labeled Ribonucleosides with <i>N</i>-<i>tert</i>-Butylaminoxyl Radicals
作者:Mariko Aso、Takeshi Ikeno、Kouji Norihisa、Masakazu Tanaka、Noboru Koga、Hiroshi Suemune
DOI:10.1021/jo015532s
日期:2001.5.1
corresponding stable spin-labeled nucleosides (8a-d and 1a-d), which were confirmed by EPR spectroscopy. Similarly, the precursors of spin-labeled pyrimidines (13, 20, and 23) were synthesized by site-selective lithiation of tri-O-protected pyrimidine derivatives (9, 18, and 21) followed by the reaction with MNP and deprotection. An EPR study showed that the aminoxyl radicals (2, 3, and 4) were stable and that
我们设计了一种新的自旋标记核苷,其带有一个N-叔丁基氨基羟自由基,该自由基被直接引入到核碱基中。合成了含有氨基基团(例如1a-d,2、3和4)的嘌呤和嘧啶核糖核苷,以研究N-叔丁基氨基甲氧基在核碱基上的稳定性和行为。三-O-甲硅烷基化的6-氯嘌呤核糖核苷(5)的锂化,然后与2-甲基-2-亚硝基丙烷(MNP)反应,得到关键化合物6a,将其进一步转化为6b-d。用Ag(2)O氧化获得的6a-d及其三醇(7a-d)导致形成相应的稳定自旋标记核苷(8a-d和1a-d),这已通过EPR光谱法确认。同样,自旋标记的嘧啶的前体(13,20,通过将三-O-保护的嘧啶衍生物(9、18和21)进行位点选择性锂化,然后与MNP反应并进行脱保护,来合成α-α和β-α和β-α和β-α-α-β-α-β-α-α-β-氨基吗啉。EPR研究表明,氨氧自由基(2、3和4)是稳定的,它们的超精细结构取决于自由基的位置。嘧啶的电子密度也影响超精细结构。