The 2-Cyano-2,2-dimethylethanimine-<i>N</i>-oxymethyl Group for the 2′-Hydroxyl Protection of Ribonucleosides in the Solid-Phase Synthesis of RNA Sequences
作者:Jacek Cieślak、Cristina Ausín、Andrzej Grajkowski、Serge L. Beaucage
DOI:10.1002/chem.201204235
日期:2013.4.2
reaction of 2‐cyano‐2‐methyl propanal with 2′‐O‐aminooxymethylribonucleosides leads to stable and yet reversible 2′‐O‐(2‐cyano‐2,2‐dimethylethanimine‐N‐oxymethyl)ribonucleosides. Following N‐protection of the nucleobases, 5′‐dimethoxytritylation and 3′‐phosphitylation, the resulting 2′‐protected ribonucleoside phosphoramidite monomers are employed in the solid‐phase synthesis of three chimeric RNA sequences
2-氰基-2-甲基丙醛与2'- O-氨氧基甲基核糖核苷的反应可产生稳定且可逆的2' - O-(2-氰基-2-2,2-二甲基乙胺-N-氧甲基)核糖核苷。在对核碱基进行N-保护,5'-二甲氧基三苯甲基化和3'-磷酸化之后,得到的2'-保护的核糖核苷亚磷酰胺单体被用于三个嵌合RNA序列的固相合成,每个序列的嘌呤/嘧啶比率不同。在5‐苄硫基‐1 H存在下进行亚磷酰胺单体的活化时-四唑,在180 s内平均获得99%的耦合效率。RNA链装配完成后,在标准碱性条件下进行核苷酸碱基和磷酸盐保护基的去除以及从固相支持物中释放序列,而2' - O-(2-氰基-2,通过用氟化四正丁基铵(0.5 m)处理可实现2-二甲基乙胺基-N-氧甲基)保护基(不释放RNA烷基化副产物)在干燥的DMSO中于55°C下放置24–48 h。通过聚丙烯酰胺凝胶电泳(PAGE),酶水解和基质辅助激光解吸/电离(MALDI)质谱对完全