Abstract
•Novel (Z)-pyrazol β-keto-enol tautomer derivative was prepared and characterized by XRD and other spectra.•Exp. data were successfully explained based on HSA, NCI and DFT-computational calculations.•The Exp. enol↔ diketone tautomerism was supported by DFT intramolecular single proton transfer mechanism.•The title compound exhibited a potent inhibitory activity α-glucosidase enzyme.
The new (Z)-pyrazol β-keto-enol as model-molecule has been prepared in accepted high yield; the structure was investigated by X-ray single crystal diffraction (XRD) and Density Functional Theory (DFT) modeling. Several hydrogen bonds interactions were recorded experimentally via XRD and theoretically via Hirshfeld surface analysis (HSA) calculations. The recorded vibrational frequencies FT-IR were further compared to computed ones. Natural Population Analysis (NPA), Mulliken Atomic Charge (MAC), and Molecular Electrostatic Potential (MEP) has been carried out to complete the set of theoretical tools. The HOMO/LUMO, density of state (DOS) and TD-SCF/DFT were applied to compare these quantum parameters with experimental electron transfer and direct optical activity. DFT calculations, natural bond orbital (NBO) analysis and non-covalent interactions (NCI) analysis were used to explore the mechanism of the single proton keto-enol intra-migration tautomerization reaction. Additionally, the desired compound was screened for its in-vitro α-amylase and α-glucosidase inhibitory activities. The title compound reflected a potent inhibitory activity α-glucosidase enzyme with IC50 value of 72.20 ± 1.50 µM. Moreover, the solved 3D-crystal structure was used for 1BNA DNA docking evaluation.