Stabilisation of nucleic acid secondary structures by oligonucleotides with an additional nucleobase; synthesis and incorporation of 2′-deoxy-2′-C-(2-(thymine-1-yl)ethyl)uridine
作者:Søren Ljungberg Pedersen、Poul Nielsen
DOI:10.1039/b510167k
日期:——
A nucleoside with two nucleobases is incorporated into oligonucleotides. The synthetic building block, 2'-deoxy-2'-C-(2-(thymine-1-yl)ethyl)uridine, 2, is prepared from uridine via 5',3'-TIPDS-protected 2'-deoxy-2'-C-allyluridine by an oxidative cleavage of the allyl group, a Mitsunobu reaction for the introduction of thymine and appropriate deprotection reactions. This compound is converted into a
将具有两个核碱基的核苷掺入寡核苷酸中。合成的结构单元2'-脱氧-2'-C-(2-(胸腺嘧啶-1-基)乙基)尿苷2是通过5',3'-TIPDS保护的2'-脱氧-尿苷由尿苷制备的通过烯丙基的氧化裂解,引入胸腺嘧啶的Mitsunobu反应和适当的脱保护反应来形成2'-C-烯丙啶。将该化合物转化成DMT保护的亚磷酰胺,并一次掺入13-mer寡脱氧核苷酸序列中,一次掺入等位LNA修饰的寡脱氧核苷酸中,并掺入12-mer寡脱氧核苷酸中间四次。这些序列与不同的互补DNA和RNA序列混合,以研究其他核苷酸碱基在双链体,凸起双链体和三向接头中的作用。发现第一个额外的胸腺嘧啶在DNA-RNA双链体中被很好地容纳,而DNA-DNA双链体则稍微不稳定。发现在分支点与附加的胸腺嘧啶的三向连接在DNA-DNA和DNA-RNA环境中均稳定,但在使用修饰的LNA序列时不稳定。然而,在含Mg2 +的缓冲液中,发现三向连接的