Structural and solvent effects on the 13C and 15N NMR chemical shifts of indoloquinoline alkaloids:: experimental and DFT study
Structural and solvent effects on the 13C and 15N NMR chemical shifts of indoloquinoline alkaloids:: experimental and DFT study
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DOI：
10.1002/mrc.2125
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发表时间：
2008-01-01
影响因子：
2
通讯作者：
Marek, Radek
中科院分区：
文献类型：
--
作者：
Tousek, Jaromir;Van Miert, Sawne;Marek, Radek
吲哚喹啉类生物碱是一类重要的抗疟、抗菌和抗病毒化合物。它们通过嵌入优先与含有非交替CC位点的富含gc的序列结合。与生物大分子形成的配合物的稳定性取决于非共价结合。在本研究中，采用核磁共振波谱和密度泛函理论（DFT） （B3LYP/6-31G**）计算研究了吲哚喹啉类化合物与溶剂形成分子间相互作用的能力。讨论了吲哚喹啉碱和相应的盐酸的核磁共振数据与结构的关系。真空和溶液中屏蔽常数的DFT计算允许研究环境对核磁共振参数的影响。考虑溶剂效应的计算表明，电子分布的各向异性发生了显著变化，这反映在化学屏蔽张量的跨度上(Omega = sigma（11) - sigma(33)）。溶剂对C-13和N-15屏蔽张量跨度的影响与原子类型有关，其中溶质-溶剂相互作用的影响显著。版权所有(C) 2008约翰威利父子有限公司
Indoloquinoline alkaloids represent an important class of antimalarial, antibacterial and antiviral compounds. They have been shown to bind to DNA via intercalation preferentially at GC-rich sequences containing nonalternating CC sites. The stability of complexes formed with biological macromolecules depends on noncovalent binding. In the present study, the ability of indoloquinolines to form intermolecular interactions with solvents was investigated by using NMR spectroscopy and density functional theory (DFT) (B3LYP/6-31G**) calculations. NMR data measured for indoloquinoline bases and the corresponding hydrochlorides are discussed in relation to the structure. DFT calculations of shielding constants in vacuo and in solution allowed the investigation of the influence of the environment on the NMR parameters. Calculations incorporating solvent effects indicated significant changes in the anisotropy of the electron distribution, reflected in the span of the chemical shielding tensor (Omega = sigma(11) - sigma(33)). Solvent effects on the span of the C-13 and N-15 shielding tensor depended on the type of atom and the data indicated a significant influence of solute-solvent interactions. Copyright (C) 2008 John Wiley & Sons, Ltd.