An expedient approach for the synthesis of pyrrolo[3,2-d]pyrimidines (9-deazaxanthines) and furo[3,2-d]pyrimidine via radical cyclization
作者:K.C. Majumdar、Shovan Mondal
DOI:10.1016/j.tet.2009.09.059
日期:2009.11
A new efficient route for the synthesis of substituted 9-deazaxanthines in excellent yields via aza-Claisen rearrangement followed by radical cyclization has been achieved. This methodology has also been applied to the synthesis of furo[3,2-d]pyrimidine.
通过氮杂-克莱森重排,然后进行自由基环化,已经获得了一种新的有效途径,用于以优异的产率合成取代的9-脱氮黄嘌呤。该方法也已经应用于呋喃并[3,2- d ]嘧啶的合成。
Moltke-Leth, Claus; Joergensen, Karl Anker, Journal of the Chemical Society. Perkin transactions II, 1993, # 8, p. 1487 - 1490
Structural changes of an abasic site in duplex DNA affect noncovalent binding of the spin label ç
作者:Sandip A. Shelke、Snorri Th. Sigurdsson
DOI:10.1093/nar/gkr1210
日期:2012.4
The influence of structural changes of an abasic site in duplex DNA on noncovalent and site-directedspinlabeling (NC-SDSL) of the spinlabel ç were examined with electron paramagnetic resonance (EPR) spectroscopy. The binding affinities of ç to sixteen different DNA duplexes containing all possible sequences immediately flanking the abasic site were determined and the results showed that the binding
在双链DNA上的自旋标记的非共价和位点定向自旋标记(NC-SDSL)脱碱基位点的结构变化的影响ç与检查电子顺磁共振(EPR)波谱法。测定了ç与 16 个不同 DNA 双链体的结合亲和力,该双链体包含紧邻无碱基位点的所有可能序列,结果表明ç的结合高度依赖于侧翼序列。通常,5'-dG 核苷酸有利于自旋标记的结合。特别是,5'-d(G__T) 是最好的结合序列,而 5'-d(C__T) 表现出最低的亲和力。将无碱基位点接头的结构从四氢呋喃类似物 ( F ) 更改为核苷酸C3 -间隔( C 3)不会明显影响ç与无碱基位点的结合。为了有效结合ç,无碱基位点需要位于距离双链末端至少四个碱基对的位置。在ç 的N3 处引入甲基取代基不会改变结合亲和力,但观察到 N3-乙基和-丙基的结合降低。这些结果将指导核酸 NC-SDSL 的无碱基位点受体和自旋标记配体的设计。
Moltke-Leth, Claus; Joergensen, Karl Anker, Acta Chemica Scandinavica, 1993, vol. 47, # 11, p. 1117 - 1121