Iramain Maximiliano A, Hidalgo José Ruiz, Sundius Tom, Brandán Silvia Antonia
Cátedra de Química General, Instituto de Química Inorgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471 (4000), San Miguel de Tucumán, Tucumán, Argentina.
Department of Physics, University of Helsinki, Finland.
Heliyon. 2022 Aug 6;8(8):e10102. doi: 10.1016/j.heliyon.2022.e10102. eCollection 2022 Aug.
In this research, a combined study on structures and vibrational spectra of antiviral rimantadine have been performed using hybrid B3LYP/6-311++G∗∗ calculations and the scaled quantum force field (SQMFF) procedure. Harmonic force fields and scaled force constants of Free Base (FB), Cationic (CA) and Hydrochloride (HCl) species derived from the antiviral rimantadine have been calculated in gas phase and in aqueous solution using normal internal coordinates and scaling factors. Good correlations were acquired comparing the theoretical IR, Raman, H- C-NMR and UV spectra of three species with the analogous experimental ones, suggesting probably, the presence of all them in both phases. The main force constants of three species have evidenced lower values than the corresponding to antiviral amantadine. The ionic character of N1-H33⋯Cl36 bond of HCl species in aqueous solution evidence positive Mulliken charge on N1 atom indicating that this species is as CA one. Rimantadine presents higher solvation energies in water than other antiviral species, such as chloroquin, niclosamide, cidofovir and brincidofovir. The FB and HCl species of rimantadine are slightly less reactive than the corresponding to amantadine while the opposite is observed for the CA species. The predicted ECD spectra for the FB and CA species show positive Cotton effect different from the negative observed for the HCl one. These different behaviours of three species of rimantadine could probably explain the differences observed in the intensities of bands predicted in the electronic spectra of these species.
在本研究中，使用混合B3LYP/6 - 311++G**计算方法和标度量子力场（SQMFF）程序，对抗病毒药物金刚乙胺的结构和振动光谱进行了联合研究。利用正常内坐标和标度因子，计算了气相和水溶液中源自抗病毒药物金刚乙胺的游离碱（FB）、阳离子（CA）和盐酸盐（HCl）物种的谐性力场和标度力常数。将三种物种的理论红外光谱、拉曼光谱、H - C - NMR光谱和紫外光谱与类似的实验光谱进行比较，获得了良好的相关性，这可能表明它们在两个相中均存在。三种物种的主要力常数已证明低于相应的抗病毒药物金刚烷胺。水溶液中HCl物种的N1 - H33⋯Cl36键的离子特性表明N1原子上存在正的穆利肯电荷，这表明该物种与CA物种一样。金刚乙胺在水中的溶剂化能高于其他抗病毒物种，如氯喹、氯硝柳胺、西多福韦和布林西多福韦。金刚乙胺的FB和HCl物种的反应性略低于相应的金刚烷胺，而CA物种则相反。预测的FB和CA物种的ECD光谱显示出正的科顿效应，与HCl物种观察到的负效应不同。金刚乙胺三种物种的这些不同行为可能解释了在这些物种的电子光谱中预测的谱带强度所观察到的差异。
