Vibrational spectroscopy, reactive site analysis and molecular docking studies on 2-[(2-amino-6-oxo-6,9-dihydro-3H-purin-9-yl)methoxy]-3-hydroxypropyl (2S)-2-amino-3-methylbutanoate

摘要

A complete vibrational analysis on 2-[(2-amino-6-oxo-6,9-dihydro-3H-purin-9-yl)methoxy]-3-hydroxypropyl (2S)-2-amino-3-methylbutanoate is carried out experimentally and theoretically using Gaussian03W software package. The optimized molecular structure, the vibrational frequencies were obtained theoretically by using B3LYP/6-311++G(d,p) as the basis set. The electronic properties of the compound was analysed from the UV-Vis spectrum recorded experimentally and theoretical results evaluated using two different solvent methods such as, PCM (Point continuum model) and SMD (Solvent model density) in aqueous phase. Band gap energy calculated from the HOMO-LUMO gap was 4.585 eV which was comparable to that of bioactive molecules. The charge transfer within the molecule due to excitation was observed for all three excited states and the isosurfaces were obtained from multiwfn software. Electrostatic potential (ESP) map, Electron localization function (ELF) map and Localized orbital locator (LOL) map were obtained from multiwfn software. The ESP map generated using VMD, points out the surface extremas where the global surface minimum is seen at the oxygen atom with the value -60.3528 and global surface maximum near the hydrogen atom with the value 71.3131. Natural Bond Orbital analysis has been carried out to explain the charge transfer (or) delocalization of charge due to the intermolecular and intramolecular interactions. Chemical shielding effect of the atoms in the molecule from NMR spectrum was analysed. Drug likeness parameters were calculated and the anti-viral activity of the title compound against various viral proteins was revealed from molecular docking studies. (C) 2019 Elsevier B.V. All rights reserved.