Adjusting the Structure of 2′-Modified Nucleosides and Oligonucleotides via C4′-α-F or C4′-α-OMe Substitution: Synthesis and Conformational Analysis
作者:Elise Malek-Adamian、Mihai Burai Patrascu、Sunit Kumar Jana、Saúl Martínez-Montero、Nicolas Moitessier、Masad J. Damha
DOI:10.1021/acs.joc.8b01329
日期:2018.9.7
namely, 2′,4′-diOMe-rU, 2′-OMe,4′-F-rU, and 2′-F,4′-OMe-araU, via stereoselective introduction of fluorine or methoxy functionalities at the C4′-α-position of a 4′,5′-olefinic intermediate. Conformational analyses of these nucleosides and comparison to other previously reported 2′,4′-disubstituted nucleoside analogues make it possible to evaluate the effect of fluorine and methoxy substitution on the
我们通过立体选择性介绍报告了三个核苷类似物,即2',4'-diOMe-rU,2'-OMe,4'-F-rU和2'-F,4'-OMe-araU的首次合成。氟在4',5'-烯烃中间体的C4'-α-位上的官能度。这些核苷的构象分析以及与其他先前报道的2',4'-双取代核苷类似物的比较,使得可以通过NMR,X射线衍射和计算方法评估氟和甲氧基取代对糖皱的影响。我们发现,C4'-α-F/ OMe取代基增强了2'-OMe-rU的C3' -endo(北方)构象。此外,主要的C2'-endo(南/东)在这些取代基在C4'处引入后,2'-F-araU的构象转换为C3'-endo。核苷类似物通过标准亚磷酰胺化学方法掺入DNA和RNA寡核苷酸中,并通过UV热熔实验评估它们对同双链和异双链热稳定性的影响。我们发现4'-取代基可以调节亲本2'-修饰的低聚物的结合亲和力,根据双链体类型诱导适度的去稳定化或稳定化作用。这项