Quantum mechanical origin of QSAR: theory and applications

Molecular Quantum Similarity: Theory and Applications

“…70 In addition to these plots, several instances have involved Kruskal trees and other algorithms. 9,[62][63][64][65][66]70 A second technique for clustering, used on several occasions, 59,70,71 consists of the construction of tree graphs or dendrograms. There, we manipulate the similarity matrices in such a way as to show graphically the proximity relations between different molecules.…”

“…53 However, it has been not until recently that the mathematical and physical foundations of QS have been developed in a series of publications. 5,[8][9][10]65,68,[148][149][181][182][183][184][185][186] In those articles, several new theoretical definitions, related to old concepts, were described. The first idea described was the so-called tagged set concept.…”

“…Quantum QSAR is, however, outside the scope of this chapter because of its involved nature, which would require a lengthy and profound discussion on both the theoretical aspects as well as the applications. Reviews of quantum QSAR may be found in Carbó -Dorca et al, [9][10][11][12] and more background in the mathematical aspects may be found in Carbó -Dorca et al [183][184][185][186] Although a limited number of examples of molecular quantum similarity applications have been described in this chapter, including chirality, the holographic electron density theorem, molecular clustering and visualization, calculation of log P and the Hammett sigma constant, molecular quantum similarity has many other applications. We can mention the optimization of parameters in hybrid density functionals, in which parameters are optimized by pursuing maximal similarity between the DFT densities and high-level ab initio electron densities 207,208 or by investigating the influence of solvation on electron densities 209 as examples.…”

Overview of Quantitative Structure–Activity Relationships (QSAR)

“…Compilations of these and related substituents constants are available in the literature (Hansch and Hoekman 1995). The recent explosion in the number of molecular descriptors is partly due to ease by which they may be generated by computational means, such as molecular orbital methods (Warne and Nicholson 2000;Karelson et al 1996;Carbo-Dorca et al 2000; recent examples where this has been done on a grand scale may be found in papers by Beck et al 1998). There has also been a focus on developing fragment descriptors that are very computationally efficient.…”

Omeprazole and analogue compounds: a QSAR study of activity against Helicobacter pylori using theoretical descriptors

“…The properties and behaviour of a given molecule or set of molecules are simulated using quantum and classical methods [7,8]. These simulations provide many properties which can be used in medicinal chemistry and to explain correlations between structure and activity [9]. In molecular modelling processes, biological activity is usually studied using a set of compounds with similar structures.…”