Synthesis and Structure of Novel Conformationally Constrained 1‘,2‘-Azetidine-Fused Bicyclic Pyrimidine Nucleosides: Their Incorporation into Oligo-DNAs and Thermal Stability of the Heteroduplexes
作者:Dmytro Honcharenko、Oommen P. Varghese、Oleksandr Plashkevych、Jharna Barman、Jyoti Chattopadhyaya
DOI:10.1021/jo052115x
日期:2006.1.1
azetidine-fused furanose sugar is locked in a North-East conformation with pseudorotational phase angle (P) in the range of 44.5−53.8° and sugar puckering amplitude (φm) of 29.3−32.6° for the azetidine-modified T, U, C, and 5-Me-C nucleosides. Thermal denaturation studies of azetidine-modified oligo-DNA/RNA heteroduplexes show that the azetidine-fused nucleosides display improved binding affinities when compared
的新颖1'的合成,2'-氨基亚甲基桥接的(6-氮杂-2-氧杂双环〔3.2.0〕庚烷)‘氮杂环丁烷’嘧啶核苷和它们的转换为相应的亚磷酰胺构建模块(20,39,和42),用于报道了自动化的固相寡核苷酸合成。从已知的糖中间体6 - O-苄基-1,2:3,4-双-O-异亚丙基-d开始,通过两种不同的策略合成了新型双环核苷“氮杂环丁烷”单体-psi呋喃糖。通过分子建模(从头算和MD模拟)和NMR进行的构象分析表明,氮杂环丁烷融合的呋喃糖糖被锁定在东北构象中,假旋转相角(P)在44.5-53.8°范围内,并且糖的起皱幅度(φ米)的29.3-32.6°为氮杂环丁烷改性Ť,ü,ç,和5-ME- ç核苷。氮杂环丁烷修饰的寡聚DNA / RNA异源双链的热变性研究表明,与以前合成的东北-东北糖约束的氧杂环丁烷融合类似物相比,氮杂环丁烷融合的核苷显示出改善的结合亲和力。