Applications of conceptual density functional theory in reference to quantitative structure–activity / property relationship

Abstract

To predict the biological effects of chemical compounds based on mathematical and statistical relationships, quantitative structure–activity relationship (QSAR) approach is used. Based on the molecular characteristics of diverse substances, Quantitative Structure–Property Relationship (QSPR) techniques estimate the physiochemical attributes whereas Quantitative Structure Toxicity Relationship (QSTR) is used as a link between the molecular structure of species and its toxicity. These ligand-based computational screening methods offer a cost-effective replacement for laboratory-based screening procedures. Different QSTR models are established to understand the biological activities related to toxicity. Density Functional Theory (DFT) and ab-initio techniques are used to examine external acute toxicity using Quantum Chemical (QC) descriptors and the electron correlation contribution. Conceptual Density Functional Theory (CDFT) based global and local descriptors have wide applications in analysing various physical and chemical characteristics of chemical species. The descriptors like chemical hardness, electronegativity, electrophilicity index, HOMO–LUMO energy, and enthalpy are found reliable to predict the model in terms of available experimental data. Various mathematical models are established through Multi Linear Regression (MLR) analysis which links the calculated descriptors with their biological activities. In this review, the applications of CDFT-based descriptors, are described in detail for QSAR / QSPR/ QSTR studies.