Observation of quantum signature in rivastigmine chemical bond break-up and quantum energetics, spectral studies of anti-Alzheimer inhibitors

M. Rejwan Ali, Mihaly Mezei

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Semi-empirical calculations on the torsion potential for dihedral angle of rivastigmine linking NAP and Carbamyle moieties consistently show regions of several discontinuities and a cusp indicating molecular instability and eventual break-up of rivastigmine observed in the X-ray structure. The phenomena can be explained both by definition of large classical force or quantum nature of chemical bond break-up. Also, to better understand the molecular properties and quantum energetics of the inhibitor molecules, we have performed several ab initio based calculations on all four inhibitors at equilibrium geometry, in ground state and gas phase using the density functional theory level wB97X/6-31G* and HF/6-31G*. A number of properties like computational vibrational (IR), Raman and nuclear magnetic resonance (NMR) spectra as well as HOMO and LUMO orbital energies at optimized geometries have been computed by SPARTAN16 and Gaussian16 utilities. Also, the thermodynamic and QSAR properties of the inhibitors have been assessed and compared by a number of different semi-quantum, Hartree-Fock and density functional methods. The theoretical NMR and IR spectra have been benchmarked against experimental spectrum to compare and assess suitability of the computational methodologies and basis set levels for the calculations. Communicated by Ramaswamy H. Sarma.

Original languageEnglish
Pages (from-to)118-128
Number of pages11
JournalJournal of Biomolecular Structure and Dynamics
Volume39
Issue number1
DOIs
StatePublished - 2021

Keywords

  • Density functional theory (DFT)
  • Hartree-Fock methods (HF)
  • equilibrium and transition states geometries
  • quantum signature
  • torsional potential energy

Fingerprint

Dive into the research topics of 'Observation of quantum signature in rivastigmine chemical bond break-up and quantum energetics, spectral studies of anti-Alzheimer inhibitors'. Together they form a unique fingerprint.

Cite this