QUANTUM STUDY OF GEOMETRIC PROPERTIES OF THE ANTI-HIVCOUMARIN HERACLENOL: A STUDY OF DENSITY FUNCTIONAL THEORY (DFT)

Coumarins are a class of secondary metabolites derived from cinnamic acid, widely distributed in the plant kingdom, which present important biological activities (antioxidant, anti-inflammatory, anticoagulant, antiviral and anticancer). Heraclenol is a coumarin that exhibits HIV replication inhibitory activity in vitro. Molecular modeling consists of a set of features and software for visualization, construction, editing and analysis of molecules that serve as the basis for pharmacological planning. The purpose of this study was to characterize electronically and structurally, coumarin Heraclenol, using the theory of functional density (DFT), as a stage of rational development of new drugs (Drug Design). The methodology of the present study was developed in the following steps: the Heraclenol molecule (obtained from the chewspider® repository) was constructed and visualized and pre-optimized using Avogadro® software. Afterwards, the heraclenol structure was optimized through the principle of energy minimization, using the DFT (functional density theory), calculations performed with the GAMESS software by the Hartree-Fock method with hybrid functions B3LYP and the base function 6 311G **, obtaining the molecular structure with potential energy of - 2136.01968455 Eh. The optimization of the structure generated some results as: Components (Nuclear repulsion: 1808.5375955740 Eh; Electronic energy: -1070.3301436839 Eh; An electric energy: -5053.8978063137 Eh, Electric energy two: 2175.0300670558 Eh), Components Virial (kinetic energy: 1065.6895408749 Eh; Virial: 2,0043545541); Dipole Moment (4.88971 Debye). With the data obtained from the optimization, it was possible to plot the surface map of electrostatic potential (MESP), making it possible to identify the regions of higher nucleophilicity in the oxygen atoms (O1, O2, O3, O5, O6) and the more electrophilic region in the hydrogen atoms (H23, H24, H34, H35, H36, H37, H38), justified by the difference in electronegativity between the oxygen and hydrogen atoms. It was also possible to plot the HOMO frontier orbitals (-6.121262 eV) and LUMO (-1.893912 eV). Using the Homo and Lumo values, it was possible to calculate several molecular descriptors such as: Calculated Ionization Potential (I = -6, 122562 eV), electronic affinity (A = -1.893912 eV), chemical motility (S = -0.23648 eV), chemical potential (η = -2,11432 eV), electrophilicity index (ω = -3.79931 eV), electronic chemical potential (μ = 4.00824 eV), Electronegativity (χ = -4.008237 eV) which help to predict the formation of chemical bonds and the physical and chemical properties of the compound. The present work is a fundamental step for future studies of drug design, aiming at understanding and promoting the antiviral potential of coumarin Heraclenol. neutral atom in the gas phase, chemical motility (S = -0.23648 eV), electronic chemical potential (ω = -4.008237 eV), and chemical hardness (η = -2,11432 eV), electrophilicity index (ω = -3.79931 eV), which help to predict formation of chemical bonds and the physical and chemical properties of the compound.