ETA index in QSAR

Quantitative structure-activity relationships (QSARs) represent predictive models derived from application of statistical tools correlating biological activity (including therapeutic and toxic) of chemicals (drugs/toxicants/environmental pollutants) with descriptors representative of molecular structure and/or property. QSARs are being applied in many disciplines like risk assessment, toxicity prediction, and regulatory decisions apart from drug discovery and lead optimization .
Topological descriptors are derived from hydrogen-suppressed molecular graphs, in which the atoms are represented by vertices and the bonds by edges. The connections between the atoms can be described by various types of topological matrices (e.g., distance or adjacency matrices), which can be mathematically manipulated so as to derive a single number, usually known as graph invariant, graph-theoretical index or topological index (TI) . In consequence, the TIs can be defined as two-dimensional descriptors that can be easily calculated from the molecular graphs, and do not depend on the way the graph is depicted or labeled and no need of energy minimization of the chemical structure.
The extended topochemical atom (ETA) indices have been developed based on refinement of TAU descriptors which were originally developed in late eighties in the valence electron mobile (VEM) environment. ETA descriptors have been used in development of predictive QSAR/QSPR/QSTR models.
References
W. Tomg, H. Hong, Q. Xie, L. Shi, H. Fang, R. Perkins, Assessing QSAR limitations - a regulatory perspective. Curr. Comput. Aided Drug. Des. 1, 195 -205 (2005).
J. C. Dearden, In silico prediction of drug toxicity. J. Comput.-Aided Mol. Des., 17, 119-127 (2003).
H. González-Díaz, S. Vilar, L. Santana, E. Uriarte, Medicinal chemistry and bioinformatics-current trends in drugs discovery with networks topological indices. Curr. Top. Med. Chem., 7, 1015-1029 (2007).
H. González-Díaz, Y. González-Díaz, L. Santana, F. M. Ubeira, E. Uriarte, Proteomics, networks and connectivity indices. Proteomics, 8, 750-778 (2008).
K. Roy, G. Ghosh, Introduction of Extended Topochemical Atom (ETA) Indices in the Valence Electron Mobile (VEM) Environment as Tools for QSAR/QSPR Studies. Internet Electron. J. Mol. Des., 2, 599-620 (2003) http://www.biochempress.com.
K. Roy, G. Ghosh, QSTR with extended topochemical atom indices. 2. Fish toxicity of substituted benzenes. J. Chem. Inf. Comput. Sci., 44, 559-567 (2004) http://dx.doi.org/10.1021/ci0342066
K. Roy, G. Ghosh, QSTR with extended topochemical atom indices. 3. Toxicity of nitrobenzenes to Tetrahymena pyriformis. QSAR Comb. Sci., 23, 99-108 (2004) http://dx.doi.org/10.1002/qsar.200330864
K. Roy, G. Ghosh, QSTR with Extended Topochemical Atom Indices. 4. Modeling of the Acute Toxicity of Phenylsulfonyl Carboxylates to Vibrio fischeri Using Principal Component Factor Analysis and Principal Component Regression Analysis. QSAR Comb. Sci., 23, 526-535 (2004) http://dx.doi.org/10.1002/qsar.200430891
K. Roy, G. Ghosh, QSTR with Extended Topochemical Atom Indices. Part 5. Modeling of the Acute Toxicity of Phenylsulfonyl Carboxylates to Vibrio fischeri Using Genetic Function Approximation. Bioorg. Med. Chem., 13, 1185-1194 (2005) http://dx.doi.org/10.1016/j.bmc.2004.11.014
K. Roy, G. Ghosh,, QSTR with extended topochemical atom (ETA) indices. VI. Acute toxicity of benzene derivatives to tadpoles (Rana japonica). J. Mol. Model., 12, 306-316 (2006) http://dx.doi.org/10.1007/s00894-005-0033-7
K. Roy, I. Sanyal, QSTR with Extended Topochemical Atom Indices. 7.QSAR of Substituted Benzenes to Saccharomyces cerevisiae. QSAR Comb. Sci., 25, 359-371 (2006) http://dx.doi.org/10.1002/qsar.200530172
K. Roy, G. Ghosh, QSTR with extended topochemical atom (ETA) indices. 8. QSAR for the inhibition of substituted phenols on germination rate of Cucumis sativus using chemometric tools. QSAR Comb. Sci., 25, 846-859. (2006) http://dx.doi.org/10.1002/qsar.200510211
K. Roy, G. Ghosh, QSTR with extended topochemical atom (ETA) indices. 9. Comparative QSAR for the toxicity of diverse functional organic compounds to Chlorella vulgaris using chemometric tools. Chemosphere, 70, 1-12 (2007) http://dx.doi.org/10.1016/j.chemosphere.2007.07.037
K. Roy, I. Sanyal, P. P. Roy, QSPR of the bioconcentration factors of nonionic organic compounds in fish using extended topochemical atom (ETA) indices. SAR QSAR Environ. Res., 17, 563-582 (2006) http://dx.doi.org/10.1080/10629360601033499
K. Roy, I. Sanyal, G. Ghosh, QSPR of n-octanol/water partition coefficient of nonionic organic compounds using extended topochemical atom (ETA) indices. QSAR Comb. Sci., 25, 629-646 (2006) http://dx.doi.org/10.1002/qsar.200610112
D. K. Pal, C. Sengupta, A. U. De, A New Topochemi
cal Descriptor (TAU) in Molecular Connectivity Concept: Part I -- Aliphatic Compounds. Indian J. Chem., 27B, 734-739 (1988).
D. K. Pal, C. Sengupta, A. U. De, Introduction of A Novel Topochemical Index and Exploitation of Group Connectivity Concept to Achieve Predictability in QSAR and RDD. Indian J. Chem., 28B, 261-267 (1989)
D. K. Pal, M. Sengupta, C. Sengupta, A. U. De, QSAR with TAU (t) indices: Part I -- Polymethylene Primary Diamines as Amebicidal Agents. Indian J. Chem., 29B, 451-454 (1990)
D. K. Pal, S. K. Purkayastha, C. Sengupta, A. U. De, Quantitative Structure-Property Relationships with TAU indices: Part I - Research Octane Numbers of Alkane Fuel Molecules Indian J. Chem., 31B, 109-114 (1992)
K. Roy, D. K. Pal, A. U. De, C. Sengupta, Comparative QSAR with Molecular Negentropy, Molecular Connectivity, STIMS and TAU Indices : Part I. Tadpole Narcosis of Diverse Functional Acyclic Compounds. Indian J. Chem., 38B, 664-671 (1999)
K. Roy, D. K. Pal, A. U. De, C. Sengupta, Comparative QSAR Studies with Molecular Negentropy, Molecular Connectivity, STIMS and TAU Indices. Part II : General Anaesthetic Activity of Aliphatic Hydrocarbons, Halocarbons and Ethers. Indian J. Chem., 40B, 129-135 (2001)
K. Roy, A. Saha, Comparative QSPR Studies with Molecular Connectivity, Molecular Negentropy and TAU Indices. Part I: Molecular Thermochemical Properties of Diverse Functional Acyclic Compounds. J. Mol. Model., 9, 259-270 (2003)
K. Roy, A. Saha, Comparative QSPR Studies with Molecular Connectivity, Molecular Negentropy and TAU Indices. Part 2: Lipid-Water Partition Coefficient of Diverse Functional Acyclic Compounds. Internet Electron. J. Mol. Des., 2, 288-305 (2003) http://www.biochempress.com
K. Roy, A. Saha, QSPR with TAU Indices: Water Solubility of Diverse Functional Acyclic Compounds. Internet Electron. J. Mol. Des., 2, 475-491 (2003) http://www.biochempress.com
K. Roy, S. Chakroborty, C. C. Ghosh, A. Saha, QSPR with TAU Indices: Molar Thermochemical Properties of Diverse Functional Acyclic Compounds. J. Indian Chem. Soc., 81, 115-125 (2004)
K. Roy, A. Saha, QSPR with TAU Indices: Boiling Points of Sulfides and Thiols. Indian J. Chem., 43A, 1369-1376 (2004)
K. Roy, A. Saha, QSPR with TAU indices: Molar refractivity of diverse functional acyclic compounds. Indian J. Chem., 44B, 1693-1707 (2005)
K. Roy, A. Saha, QSPR with TAU Indices: Part 5. Liquid Heat Capacity of Diverse Functional Organic Compounds. J Indian. Chem. Soc., 83, 351-355 (2006)

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