8-Aza-7-deazaguanine nucleosides and oligonucleotides with octadiynyl side chains: synthesis, functionalization by the azide-alkyne ‘click’ reaction and nucleobase specific fluorescence quenching of coumarin dye conjugates
作者:Frank Seela、Hai Xiong、Peter Leonard、Simone Budow
DOI:10.1039/b822041g
日期:——
chains have steric freedom in duplex DNA. Nucleoside 2d as well as 2d-containing oligonucleotides were conjugated to the non-fluorescent 3-azido-7-hydroxycoumarin 15 by the Huisgen-Meldal-Sharpless ‘click’ reaction. Pyrazolo[3,4-d]pyrimidine nucleoside conjugate 16 shows a much higher fluorescence intensity than that of the corresponding pyrrolo[2,3-d]pyrimidine derivative 17. The quenching in the dye conjugate
通过固相合成制备了 掺入8-氮杂-7-脱氮杂-2'-脱氧鸟苷(2d)的7-(八-1,7-二炔基)衍生物的寡核苷酸。通过Sonogashira交叉偶联反应引入2d的侧链,并合成亚磷酰胺(3a,3b)。与包含未官能化的8-氮杂7-脱氮基2'-脱氧鸟苷(2a)的双链体相比,含2d的双链体更加稳定,这表明这些侧链在双链体DNA中具有空间自由度。将核苷2d和含2d的寡核苷酸偶联到非荧光的3-azido-7-羟基香豆素上15,由Huisgen-Meldal-Sharpless做出的“点击”反应。吡唑并[3,4- d ]嘧啶核苷共轭物16显示出比相应的吡咯并[2,3- d ]嘧啶衍生物17更高的荧光强度。发现在染料缀合物17中的猝灭在单体缀合物阶段比在单链或双链DNA中更强。提出了核碱基-染料接触复合物,当核碱基是堆叠的一部分时,其在单体状态下比在DNA链中更有利。具有笨重的染料缀合物的侧链很好地容纳在