A Novel Methodology for Property-Based Molecular Design Using Multiple Topological Indices

Abstract

In this work, we are introducing an algorithm that can be used for solving molecular design problems of reactive systems on a property-based platform. The property clustering technique is extended to identify a set of target properties for the components in the system that provides the optimum process performance. Once the property targets have been identified, a molecular design problem can be formulated to identify the potential candidate molecules that meet the targets identified in the previous problem. The molecular design involves the identification of potential molecules possible from the specific types of reactions in the process. To design molecules, a recently introduced concept known as molecular signature descriptors has been used. The molecular signatures can be tailored to track the changes in molecular groups in a molecule resulting from different types of chemical reactions. The changes in the chemical structure can be correlated with the changes in the properties of the molecule. Therefore, the changes in the molecular structure due to reactions can be represented as a function of the property. The developed algorithm applies different qualitative structure activity/property relationships (QSAR/QSPR) to estimate properties from the molecular structure. QSAR relationships make use of different topological indices and it has been shown that a number of topological indices of molecules can be represented in terms of molecular signatures and that it is possible to correlate the topological indices to the actual properties and biological activities. Here, the new algorithm utilizes molecular property operators on the basis of signatures for solving the inverse problem of obtaining the molecular structures that satisfy the property targets estimated in the process design step. A new set of equations are employed to ensure that the molecule meets the safety and environmental constraints as well. The principles of graph theory are incorporated to track the signatures and to avoid the generation of infeasible molecular structures.