Quantum computations of non-steroidal anti-inflammatory drug molecules using Density Functional Theory

This paper addresses the electronic states and physicochemical properties of non-steroidal anti-inflammatory drug (NSAID) namely: Ibuprofen, Ketoprofen and Flufenamic acid. The molecular structures are quantum chemically treated and geometrically optimised using density functional theory (DFT). The computed geometrical parameters are compared with the experimental data. The Mulliken charge analysis is accomplished to understand the partial charge distribution in molecules. The molecular electrostatic potential analysis has been used to identify the appropriate location for an electrophilic and nucleophilic attacking site. Frontier molecular orbitals of the molecules are estimated and analysed. The HOMO-LUMO energy gaps have been used to estimate the different global reactivity descriptors of the selected molecules under investigation. The FT-IR spectra of molecules are recorded experimentally and are computed using DFT. The potential energy distribution (PED) assignment for the computed vibrations is carried out. The NBO analysis has been used to find the most intensive interaction in molecules based on the Fock-matrix sta3bilization energy. The NLO parameters have been computed for molecules to check their suitability towards NLO based applications. The UV-absorption spectra and ADME parameters for titled molecules are also simulated.