Quantum Chemical, experimental spectroscopic, Hirshfeld surface and molecular docking studies of the anti-microbial drug Sulfathiazole

Abstract

Sulfathiazole (ST) was investigated quantum chemically by DFT approach, surface analysis by Hirshfeld and experimentally by NMR (FT-IR, UV-Visible 1H-NMR and 13C-NMR). The B3LYP method and the 6-311 ++ G (d, p) basis set were applied to optimize the molecular structure and to calculate the wavenumbers of normal vibrational modes. A detailed description of the intermolecular interactions of the crystal surface was carried out by means of Hirshfeld surface analysis and fingerprint plots found. SF is a powerful antimicrobial drug and also falls into the sulfonamide category and is one of the major building blocks in the pharmaceutical sector. The calculated bond lengths and angles were compared with the experimental bond lengths and bond angle parameters and found to be in good agreement. VEDA successfully carried out complete tasks for the distribution of potential energy. 1H-NMR and 13C-NMR shifts were estimated using the GIAO method and the results compared with experimental spectra. The TD-DFT method and the PCM solvent model were used for the analysis of electronic properties such as UV-Vis (in gas phase, ethanol and DMSO) and compared with the experimental UV-Vis spectra. The HOMO / LUMO energy results emphasize that sufficient charge transfer occurs within the molecule. The donor-acceptor connections were investigated by means of NBO analysis. The MEP surface analysis was carried out to show the charge distribution in the molecule. The degree of relative localization of electrons was analyzed using the FLF diagram. The Fukui functional analysis to find possible points of attack for various substituents and the surface of the molecular electrostatic potential (MEP) was created for the 3-D color representation. The analysis of intermolecular interactions over the Hirshfeld surface showed that ST is primarily stabilized by the formation of S — H / O — H / H — H / H — N / C — H contacts has been. The biological study like molecular docking was carried out with 17 different receptors in order to find the best ligand-protein interactions and the similarity with the active substance.