Quantum Chemical Study of Hydroxychloroquine and Chloroquine Drugs Used as a Treatment of COVID-19

Two drugs have been authorized by the Algerian health Ministry to be used in Algeria to treat coronavirus disease 2019 (COVID-19) patients, once is Hydroxychloroquine (HCQ) and the other is Chloroquine (CQ). These drugs have been theoretically studied in order to know their active sites, and vibrational and electronic properties using Density Functional Theory (DFT) at the B3LYP/6-31G (d.p) level. The optimized molecular structures, the vibrational spectra, the HOMO and LUMO properties, dipole moments, Molecular Electrostatic Potentials (MEP), and atomic charges are calculated. In addition, the reactivity of drug molecules has been discussed by calculating some descriptors such as energy gap, hardness, local softness, electronegativity, and electrophilicity.