3-Phenyl-5,6,7,8-tetrahydropyrimido[4,5-c]pyridazin-7-one as nucleobase substitute in DNA: synthesis of the 2′-deoxyribonucleoside, cyclonucleoside formation, and base pairing in oligonucleotides
作者:Hui Mei、Sachin A. Ingale、Frank Seela
DOI:10.1016/j.tet.2015.06.092
日期:2015.9
A 5,6,7,8-tetrahydro derivative of 3-phenylpyrimido[4,5-c]pyridazin-7-one 2′-deoxyribonucleoside (3) was designed as a dC mimic to form silver-mediated base pairs in DNA duplexes as reported for pyrrolo-dC 1 and imidazole-dC 2. Compared to the fully aromatic molecule 4, the nucleobase of 3 is hydrogenated with carbon-5 in the sp3 hybridization state and an additional hydrogen atom located at nitrogen-8
3-苯基嘧啶基[4,5- c ]哒嗪-7-一个2'-脱氧核糖核苷(3)的5,6,7,8-四氢衍生物被设计为dC模拟物,以在DNA双链体中形成银介导的碱基对。如对于吡咯烷-dC 1和咪唑-dC 2所报道的。相比于全芳族分子4,的核苷碱基3是氢化用在sp 3碳-5 3杂化状态和位于氮-8的附加氢原子。在芳香化条件下,核苷3进行环化成5,5'-环核苷6。该反应显然与报道的8-氮杂嘌呤核苷的环化有关。核苷3被转化为亚磷酰胺13,并被掺入寡核苷酸中。在不同的互变异构状态下,核苷3可被视为dT模拟物,而在另一种情况下可被视为dC衍生物。因此,化合物3与dA和dG形成碱基对。然而,无法检测到针对彼此面对的两个相同的核苷3残基提出的期望的银介导的碱基对。