Evstigneev M P, Rybakova K A, Davies D B
Biofizika. 2006 Jul-Aug;51(4):661-8.
The heteroassociation of the antibacterial antibiotic norfloxacin with aromatic vitamins nicotineamide and flavin mononucleotide in aqueous solution has been studied by 1H NMR spectroscopy (503 MHz). Equilibrium constants, induced proton chemical shifts, and the thermodynamic parameters (deltaH, deltaS) of the heteroassociation of molecules were determined from the concentration and temperature dependences of chemical shifts of protons of interacting aromatic molecules. An analysis of the results indicates the formation of heterocomplexes between the molecules of the vitamins and norfloxacin, which is caused by stacking interactions between aromatic chromophores and an additional intermolecular hydrogen bond in the norfloxacin-nicotinamide system. Based on the analysis of induced chemical shifts of protons of molecules, the most probable spatial structures 1:1 of norfloxacin-flavin mononucleitide and norfloxacin-nicotinamide heterocomolexes were determined by the methods of molecular modeling using the X-PLOR program.
利用503兆赫的1H核磁共振光谱法研究了抗菌抗生素诺氟沙星与芳香族维生素烟酰胺和黄素单核苷酸在水溶液中的异质缔合。根据相互作用的芳香族分子质子化学位移的浓度和温度依赖性，确定了分子异质缔合的平衡常数、诱导质子化学位移和热力学参数（ΔH、ΔS）。结果分析表明，维生素分子与诺氟沙星之间形成了异质复合物，这是由芳香发色团之间的堆积相互作用以及诺氟沙星-烟酰胺体系中额外的分子间氢键引起的。基于对分子质子诱导化学位移的分析，使用X-PLOR程序通过分子建模方法确定了诺氟沙星-黄素单核苷酸和诺氟沙星-烟酰胺异质复合物最可能的1:1空间结构。
