Progress in demonstrating total homochiral selection in montmorillonite-catalyzed RNA synthesis
作者:Prakash C. Joshi、Michael F. Aldersley、James P. Ferris
DOI:10.1016/j.bbrc.2011.09.008
日期:2011.10
The Na(+)-montmorillonite-catalyzed reactions of 5'-phosphorimidazolides of nucleosides generates RNA oligomers. The question arises as to how chiral selectivity was introduced into this biopolymer from a simple chemical system. We have demonstrated homochiral selection in quaternary reactions of a racemic mixture of D,L-ImpA and D,L-ImpU on Na(+)-montmorillonite. The dimer, trimer, tetramer and pentamer
Na(+)-蒙脱石催化的核苷5'-磷酰胺基咪唑化物反应可生成RNA低聚物。问题是如何通过简单的化学系统将手性选择性引入该生物聚合物。我们已经证明了在Na(+)-蒙脱石上D,L-ImpA和D,L-ImpU的外消旋混合物的四级反应的同手性选择。研究了二聚体,三聚体,四聚体和五聚体级分的同手性选择。通过离子交换HPLC收集产物,其末端5'-磷酸被碱性磷酸酶切割。通过反相HPLC分析这些级分,以鉴定同手性和杂手性异构体。受二聚体(63.5±0.8%)和三聚体(74.3±1.7%)的均一手性过量的鼓励,该研究扩展到了高级低聚物的分析。四元反应的四聚体和五聚体在反相柱上分别分离为26和22个异构体。它们与d-ImpA和D-ImpU在Na(+)蒙脱土上的二元反应形成的共洗脱分别显示四聚体和五聚体的92.7±2.0%和97.2±0.5%的手性。这些结果表明,Na(+)-蒙脱石不仅催化RNA的益生元合成,而且还促进同手性的选择。