Properties and Molecular docking of Antiviral to COVID-19 Chloroquine
combining DFT calculations with SQMFF approach
Abstract
Structural, electronic, topological, vibrational and molecular docking
studies have been performed for both enantiomeric S(-) and R(+) forms of
potential antiviral to COVID-19 chloroquine (CQ) combining DFT
calculations with SQMFF methodology. Hybrid B3LYP/6-311++G**
calculations in gas phase and aqueous solution predict few energy
differences between both forms. Solvation energies of S(-) and R(+) form
are predicted in -55.07 and 59.91 kJ/mol, respectively. Low solvation
energies of both forms are justified by the presence of only four donor
and acceptor H bonds groups, as compared with other antiviral agents. MK
charges on the Cl1, N2, N3 and N4 atoms and AIM calculations could
support the high stability of R(+) form in solution according to the
higher reactivity predicted for the S(-) form in this medium. Antiviral
to COVID-19 niclosamide shows higher reactivity than both forms of CQ.
Complete vibrational assignments of 153 vibration modes for both forms
and scaled force constants have been reported here. Reasonable
concordances were found between predicted and available 1H-NMR, 13C-NMR
and UV-Vis spectra. Additionally, NMR and UV-visible spectra suggest the
presence of two forms of CQ in solution. A molecular docking study was
performed to identify the potency of inhibition of Chloroquine molecule
against COVID-19 virus