Here we describe the synthesis of new 7-substituted 8-aza-7-deazaadenosine ribonucleoside phosphoramidites and their use in generating major groove-modified duplex RNAs. A 7-ethynyl analog leads to further structural diversification of the RNA via post-automated RNA synthesis azide–alkyne cycloaddition reactions. In addition, we report preliminary studies on the effects of eight different purine 7-position modifications on RNA duplex stability and pairing specificity. Finally, the effect on RNAi activity of this type of modification at eight different positions in an siRNA guide strand has been explored. Analogs were identified with large 7-position substituents that maintain adenosine pairing specificity and are well-tolerated at specific positions in an siRNA guide strand.
在这里,我们描述了新的 7 取代 8-aza-7-deazaadenosine
核糖核苷
磷酸酰胺的合成及其在生成主沟修饰双链 RNA 中的应用。通过自动 RNA 合成后的
叠氮-炔环加成反应,7-
乙炔基类似物使 RNA 的结构进一步多样化。此外,我们还报告了八种不同的
嘌呤 7 位修饰对 RNA 双链稳定性和配对特异性影响的初步研究。最后,我们还探讨了 siRNA 引导链中 8 个不同位置的此类修饰对 RNAi 活性的影响。研究发现,具有大的 7 位取代基的类似物能保持
腺苷配对特异性,并在 siRNA 引导链的特定位置具有良好的耐受性。