Molecular Modeling for Generation of Structural and Molecular Electronic Descriptors for QSAR Using Quantum Mechanical Semiempirical and ab initio Methods

Abstract

The major thrust of scienti c research is to understand and explain the biological functions of biologi-cal systems in molecular terms. The development of techniques of molecular modeling has opened theprospects for understanding the function, reactivity and properties of biological systems in terms ofmolecularstructure. QSARsquantifytheconnectionbetweenthestructureandpropertiesofmoleculesand allow the prediction of properties from structural and electronic parameters. The QSAR studiesemploy electronic, hydrophobic, structural and topological parameters of the compounds. In partic-ular, electronic parameters are considered important in the establishment of QSAR models and arehelpful to quantify di erent types of intermolecular and intramolecular interactions, as these interac-tions are usually responsible for properties of biological systems. The hydroxy substituted quinonesand their derivatives are of considerable practical importance in the eld of biology and pharmacol-ogy, as prominent family of pharmaceutically active and biologically relevant chromophores. Hydroxynaphthoquinone derivatives, in particular, have shown inhibitory e ect on DNA topoisomerase-I andantiproliferative activity and cytotoxic activity [1, 5, 6]. We have generated the molecular electronicdescriptors like the energies of HOMO and LUMO, dipole moment  ionization potentials, heat offormation, total energy E