Szatylowicz Halina, Marek Paulina H, Stasyuk Olga A, Krygowski Tadeusz M, Solà Miquel
Warsaw University of Technology, Faculty of Chemistry Noakowskiego 3 00-664 Warsaw Poland
University of Warsaw, Faculty of Chemistry Pasteura 1 02-093 Warsaw Poland.
RSC Adv. 2020 Jun 18;10(39):23350-23358. doi: 10.1039/d0ra04585c. eCollection 2020 Jun 16.
Adenine, one of the components of DNA/RNA helices, has the ability to form self-organizing structures with cyclic hydrogen bonds (A), similar to guanine quartets. Here, we report a computational investigation of the effect of substituents (X = NO, Cl, F, H, Me, and NH) on the electronic structure of 9-adenine and its quartets (A-N1, A-N3, and A-N7). DFT calculations were used to show the relationships between the electronic nature of the substituents, strength of H-bonds in the quartets, and aromaticity of five- and six-membered rings of adenine. We demonstrated how the remote substituent X modifies the proton-donating properties of the NH group involved in the H-bonds within quartets and how the position of the substituent and its electronic nature affect the stability of the quartets. We also showed the possible changes in electronic properties of the substituent and aromaticity of adenine rings caused by tetramer formation. The results indicate that the observed relationships depend on the A type. Moreover, the same substituent can both strengthen and weaken intermolecular interactions, depending on the substitution position.
腺嘌呤是DNA/RNA螺旋结构的组成成分之一，它能够与环状氢键形成自组装结构（A），类似于鸟嘌呤四联体。在此，我们报告了一项关于取代基（X = NO、Cl、F、H、Me和NH）对9-腺嘌呤及其四联体（A-N1、A-N3和A-N7）电子结构影响的计算研究。密度泛函理论计算用于展示取代基的电子性质、四联体中氢键强度以及腺嘌呤五元环和六元环芳香性之间的关系。我们证明了远程取代基X如何改变四联体中参与氢键的NH基团的质子供体性质，以及取代基的位置及其电子性质如何影响四联体的稳定性。我们还展示了由四聚体形成引起的取代基电子性质和腺嘌呤环芳香性的可能变化。结果表明，观察到的关系取决于A的类型。此外，相同的取代基根据取代位置的不同，既能增强也能减弱分子间相互作用。
