开发了通过亚胺基自由基诱导的 1,5-氢原子转移从核苷的肟亚胺酸酯快速简便地生成 4'-碳自由基。4'-碳自由基与烯烃环化,随后亚胺酸酯残基水解,提供各种 2'- O ,4'- C - 和 3'- O ,4'- C -桥接核苷。这种操作简单的方法可应用于 6' S -methyl-2'- O ,4'- C -ethylene-bridged 5-methyluridine (6' S -Me-ENA-T) 和S -的几步合成限制性乙基桥连 5-甲基尿苷 ( S -cEt-T)。
Replacement of the phosphodiester linkage in oligonucleotides by heterocycles: the effect of triazole- and imidazole-modified backbones on DNA/RNA duplex stability
摘要:
Thymidine dinucleotide analogs with imidazole-derived backbones (III and IV) were synthesized. These modified dimeric building blocks were incorporated into oligodeoxyribonucleotides. The hybridization affinity of the modified oligonucleotides for RNA complements was determined and compared to the corresponding olefinic modifications I and II. (C) 1997 Elsevier Science Ltd.
We designed a novel 2′-O,5′-N bridged nucleic acid, 2′,5′-BNAON, whose sugar puckering was fixed to S-type conformation by an N–O linkage. A dimer unit formed from 2′,5′-BNAON-U and thymidine was synthesized via a coupling reaction between a protected 2′,5′-BNAON-U monomer and a thymidine derivative. Introduction of 2′,5′-BNAON-U into DNA was carried out using conventional phosphoramidite chemistry
我们设计了一种新型的2' - O,5'- N桥接核酸2',5'-BNA ON,其糖折叠通过N - O键固定在S型构象上。通过受保护的2',5'-BNA ON -U单体与胸苷衍生物之间的偶联反应,合成了由2',5'-BNA ON -U和胸苷形成的二聚体单元。使用常规的亚磷酰胺化学和DNA合成仪将2',5'-BNA ON -U引入DNA。评价了2',5'-BNA ON -U-修饰的寡核苷酸对DNA或RNA补体的杂交能力。