Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA-92037, USA.
Chem Asian J. 2011 May 2;6(5):1252-62. doi: 10.1002/asia.201000828. Epub 2011 Mar 8.
The (3'→2')-phosphodiester glyceric acid backbone containing an acyclic oligomer tagged with 2,4-disubstituted pyrimidines as alternative recognition elements have been synthesized. Strong cross-pairing of a 2,4-dioxo-5-aminopyrimidine hexamer, rivaling locked nucleic acid (LNA) and peptide nucleic acid (PNA), with complementary adenine-containing DNA and RNA sequences was observed. The corresponding 2,4-diamino- and 2-amino-4-oxo-5-aminopyrimidine-tagged oligomers were synthesized, but difficulties in deprotection, purification, and isolation thwarted further investigations. The acyclic phosphate backbone structure of the protected oligomer seems to be prone to an eliminative degradation owing to the acidic hydrogen at the 2'-position--an arrangement that renders the oligomer vulnerable to the conditions used for the removal of the protecting groups on the heterocyclic recognition element. However, the free oligomers seem to be stable under the conditions investigated.
已合成了带有 2,4-二取代嘧啶的无环低聚物作为替代识别元件的（3'→2'）-磷酸二酯甘油酸骨架。观察到带有 2,4-二氧代-5-氨基嘧啶六元环的 2,4-二氧代-5-氨基嘧啶与互补的含腺嘌呤的 DNA 和 RNA 序列具有强烈的交叉配对，可与锁核酸（LNA）和肽核酸（PNA）相媲美。还合成了相应的 2,4-二氨基-和 2-氨基-4-氧代-5-氨基嘧啶标记的低聚物，但由于保护基上的 2'-位上的酸性氢，在脱保护、纯化和分离方面存在困难，阻碍了进一步的研究。保护低聚物的无环磷酸骨架结构似乎由于 2'-位上的酸性氢而易于消除降解 - 这种排列使低聚物容易受到用于去除杂环识别元件上的保护基团的条件的影响。然而，在研究的条件下，游离低聚物似乎是稳定的。
