VOLUME 42A 
NUMBER 6 
JUNE 2003 
CONTENTS
Review 

1207 
Chemical graph theory – facts and fiction


Graph Theory (GT) and its applications in chemistry, known as Chemical Graph Theory (CGT), appear to be two of the most misunderstood areas of theoretical chemistry. Possible causes for misunderstanding are briefly outlined and remedies suggested, including a test on the knowledge of GT and CGT. 

Papers 

1219 
On the structural interpretation of topological indices
Anton Perdih* & Branislav Perdih


To perform the structural interpretation of topological indices and physicochemical properties, the approach using structural features like the size of the molecule, the number and position of branches, separation between them, the type of branches, and the type of the branched structure is generally applicable. 

1227 
Applications of information theory in chemical graph theory
Elena V Konstantinova*, Vladimir A Skorobogatov & Maxim V Vidyuk


The application of information theory to the problem of characterizing molecular structures is presented. The information indices based on the distance in a graph are considered with respect to their correlating ability and discriminating power. 

1241 
Relations between topological indices of large chemical trees
Ivan Gutman*, Dusica Vidovic, Boris Furtula, & Aleksander Vesel


Several approximate relations have been established between eigenvalue sum and Hosoya index, greatest graph eigenvalue and connectivity index, Wiener index and smallest positive Laplacian eigenvalue, greatest Laplacian and greatest ordinary graph eigenvalue, Zenkevich and Wiener index, and hyperWiener and Wiener index and these hold good for alkanes with n=10 or fewer carbon atoms. Applying an algorithm for generating trees uniformly by random, these regularities have been tested for very large chemical trees (n=50). 

1246 
Towards branching indices


Topological indices Vj(^{1}/_{2},^{1}/_{2}), Vj(^{1}/_{2},1), Vij(^{1}/_{4},1), Vij(^{1}/_{4},^{1}/_{3}), Lj(^{1}/_{3},^{1}/_{4}), Lij(^{1}/_{4},^{1}/_{2}), lnMij(^{1}/_{3},^{1}/_{4}), as well as lnMij(‑4,1) are promising candidates for branching indices. Using a logarithm of the index or the geometric mean of the value of the nondiagonal elements of the matrix among the multiplicationderived indices, improves the situation greatly. These indices can be a good source to derive branching indices of the BI_{A} group. 

1258 
A new chemical index inspired by biological plastic evolution


This paper presents an application of plastic evolution to a new index (coordination index, I_{c}) for molecular characterization. I_{c} is applied to series of phenyl alcohols and 4‑alkylanilines, and compared to charge indices for dipole moment. The parameters needed to calculate I_{c} are the standard enthalpy of formation, molecular surface area and molecular weight. The correlations between these indices and the number of C atoms in alkyl chain indicate a homogeneous molecular structure of the phenyl alcohols and 4‑alkylanilines. 

1264 
Partition of Wienertype indices, especially for trees


Different ways are noted to partition the Wiener index of a molecular graph G into contributions associated to different substructures of G, particularly, for the case where G is a tree and the substructures are sites or bonds. Representative related partitionings for some related graph invariants are also established. Paralleling the definition of Wiener (or Hosoya) polynomials, the partitioning results are used to motivate Szeged polynomials. 

1270 
On the Wiener index decomposition for catacondensed benzenoid graphs


Some properties based on the decomposition of the Wiener index for catacondensed benzenoid graphs are presented. It is shown that if and only if , where denotes the sum of distances between vertices of degree 2 in a benzenoid graph . 

1272 
Chemical applications of the Laplacian spectrum. VII. Studies of the Wiener and Kirchhoff indices
Ivan
Gutman*, Dusica Vidovic &


Some chemical applications of the Laplacian spectra are reported. By means of Kel'mans theorem a previously known formula for the Wiener and Kirchhoff index is deduced. It is shown that the Wiener index is correlated with the algebraic connectivity. Lower and upper bounds for the Kirchhoff index are obtained. 

1279 
On variable Wiener index
Bono Lucic, Ante Milicevic, Sonja Nikolic & Nenad Trinajstic*


A variable Wiener index vW, applicable only to acyclic structures, is defined as S [n1(e) n_{2} (e)]l. As a test case, the structureboiling point modeling of isomeric octanes is used. 

1283 
Layer matrices and distance property descriptors


The TOPOCLUJ software package is designed to calculate topological descriptors from topological matrices and/or polynomials. Several weighting schemes including group electronegativity, group mass and partial charges are proposed. 

1295 
A novel topological index for coding of alternant systems


Starting with the concept of T(A) graphs for alternant hydrocarbons, a novel topological index is defined which differentiates isomeric as well as isospectral molecules very well.


1298 
Fully angular hexagonal chains extremal with regard to the largest eigenvalue
Wai
Chee Shiu*, Peter Che Bor Lam &


The hexagonal chain (unbranched catacondensed benzenoid molecule) with minimum leading eigenvalue among fully angular hexagonal chains having a given number of hexagons is reported. 

1304 
Approximating the total pielectron energy of phenylenes in terms of spectral moments


The total pelectron energy of phenylenes is approximated by means of a linear combination of spectral moments of both molecular and line graphs.


1309 
Graph energy  a useful molecular structuredescriptor
Ivan
Gutman*, Dusica Vidovic, Natasa Cmiljanovic, Svetlana Milosavljevic &


The energy of a graph is a molecular structuredescriptor applicable in QSPR and QSAR studies of both unsaturated and saturated organic compounds. 

Part 2: Applications 

Reviews 

1315 
From molecular graphs to drugs. A review on the use of topological indices in drug design and discovery
Ernesto
Estrada*, Grace Paltewicz &


®
Graphs Tis Drugs 

1330 
Applications of topological indices to structureactivity relationship modelling and selection of mineral collectors
Ramanathan Natarajan*, Palanichamy Kamalakanan & Inderjit Nirdosh




Papers 

1347 
Introducing the complete graphs for the innercore electrons




1354 
Maximum topological distances based indices as molecular descriptors for QSPR. V  Modeling the free energy of hydrocarbons
Pablo
Duchowicz, Romulo G. Sinani,


The Gibbs free energy for a set of 60 hydrocarbons is calculated on the basis of topological indices defined from the distance and detour matrices within the realm of the QSPR theory. Topological indices calculated from detour matrix yield rather satisfactory predictions of Gibbs free energy for hydrocarbons. 

1360 
Selected structural descriptors and R_M values for calculation and prediction of molar volume of homologous series of saturated fatty acids


The linear relationship between experimental molar volume values and Gutman index M for homologous series of saturated fatty acids, from ethanoic to octadecanoic is V_{m} = 4.321(±0.008)M – 32.014(±0.487), where n=17 R^{2} =99.99 F=260096 s=0.68 p<0.001. 

1368 
QSAR modeling of polychlorinated aromatic compounds
Mihaela Caprioara* & Mircea V Diudea


Polychlorinated dibenzofurans, dibenzopdioxins and biphenyls have been characterized on the basis of topological descriptors. A QSAR study is performed to emphasize the relation between some topochemical and electronic parameters and their binding affinity to the aryl hydrocarbon receptor. The main feature influencing the binding activity of these compounds is a partial chargebased descriptor, a measure of the molecular electronic properties derived using the correlation weights of these local invariants. 

1379 
Topological investigations of binary and ternary mixtures containing cyclic ether: Excess isoentropic compressibilities
Vinod K Sharma*, Romi & Satish Kumar


Speed of sound, of 1,3dioxolane + toluene or + o or + pxylene binary and 1,3dioxolane + toluene + o or + pxylene ternary mixtures have been measured over the whole mole fraction range at 298.15 K. Excess isentropic compressibility, K_{S}^{E} values have been calculated employing density values of the binary and ternary mixtures and graph theory. K_{S}^{E} values predicted by graph theoretical approach compare reasonably well with the K_{S}^{E} values determined from experimental data. 

1385 
Use of topological indices in predicting aryl hydrocarbon receptor binding potency of dibenzofurans: A hierarchical QSAR approach
Subhash
C. Basak*, Denise Mills,




1392 
True prediction by consensus for small sets of cyclooxigenase2 inhibitors
Jesus Vicente de JulianOrtiz, Emili Besalu* & Ramon GarciaDomenech


A set of 21 previously published COX2 inhibitors has been analyzed in order to obtain a new paradigm capable of obtaining true predictions of the activity.


1405 
Application of selected traditional structural descriptors to QSPR and QSAR analysis of barbiturates
Alina
Pyka*, Elzbieta Kepczynska &


Relationships between the experimental R_{M} values of the barbiturates investigated and the R_{M} values have been calculated using the relation
R_{M }=26.192(±0.498) + 14.785(±0.282) ´ m_{mph}  0.00206 (±0.00058) ´ M + 0.281 (±0.011) ´ logP_{Kowin}
[n=144; R^{2}=95.83; F=1072; s=0.097; p<0.0001; DW=1.50], where m_{mph }denotes the dipole moments of mobile phases applied, M denotes Gutman index, and logP_{Kowin} denotes theoretical partition coefficient based on atom/fragmental contributions. 

1414 
Novel topochemical descriptors for predicting antiHIV activity
Sunil
Gupta, Manjeet Singh &


The discriminating power of three novel adjacencycumdistance based chemical topological descriptors termed as eccentricadjacency topochemical indices have been investigated to estimate antiHIV activity of 107 derivatives of 6(phenylthio)thymines. The high discriminating power of eccentricadjacency topochemical indices along with other mathematical tools can be exploited for drug design. 

1426 
Use of distancebased topological indices in modeling antihypertensive activity: Case of 2aryliminoimidazolidines
Vijay
K. Agrawal*, Sneha Karmarkar, Padmakar V. Khadikar, Shachi Shrivastava &


Topological modeling of antihypertensive activity of 2aryliminoimidazolidines is reported . An excellent model is obtained in multiparametric regression containing c and logRB along with two indicator parameters. 

1436 
Equlizied electronegativity and topological indices: Application for modeling toxicity of nitrobenzene derivatives


Use of equalized electronegativity (c_{eq}) in modeling toxicity of nitrobenzene is discussed. Results show that more reliable models can be obtained when c_{eq} is combined with topological indices. The results are discussed by using multiple regression and crossvalidation procedures. 

1442 
Hosoya indices and a new approach to molecular similarity



Authors for correspondence are indicated by (*)
Vol. 42A, June 2003, pp. 12071218
Milan Randić
National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
Received 31 January 2003
Graph Theory (GT) and its applications in chemistry, the socalled Chemical Graph Theory (CGT), appear to be two of the most misunderstood areas of theoretical chemistry. We outline briefly possible causes for misunderstanding and suggest remedies, including a test on the knowledge of GT and CGT.
Vol. 42A, June 2003, pp. 12191226
Anton Perdih* & Branislav Perdih
Mala vas 12, SI1000 Ljubljana, Slovenia
Received 18 November 2002
The atom contribution approach, the bond contribution approach, the contribution of terminal or interior atoms or bonds approaches to their values do not seem to be viable approaches to perform the structural interpretation of topological indices and physicochemical properties. On the other hand, the approach of structural interpretation using the structural features like the size of the molecule, the number of branches, the position of branches, the separation between them, the type of branches, and the type of the branched structure is generally applicable.
Vol. 42A, June 2003, pp. 12271240
Elena V Konstantinova*, Vladimir A Skorobogatov, Maxim V Vidyuk
Sobolev Institute of Mathematics, Russian Academy of Sciences,
Novosibirsk, 630090, Russia, e_konsta@math.nsc.ru, skrbg@maltar.org.il
Budker Institute of Nuclear Physics, Russian Academy of Sciences, Novosibirsk, 630090, Russia, vidyuk@inp.nsk.su
Received 30 December 2002
Information theory has been used in various branches of science. During recent years it is applied extensively in chemical graph theory for describing chemical structures and for providing good correlations between physicochemical and structural properties. The application of information theory to the problem of characterizing molecular structures is presented in the paper. The information indices based on the distance in a graph are considered with respect to their correlating ability and discriminating power.
Vol. 42A, June 2003, pp. 12411245
Ivan Gutman*, Dušica Vidović& Boris Furtula
Faculty of Science, University of Kragujevac, P.O.Box 60, YU34000 Kragujevac, Yugoslavia
and
Aleksander Vesel
Department of Mathematics, PEF, University of Maribor, Koroska cesta 160, SI2000 Maribor, Slovenia
Received 16 October 2002
Several approximate relations have recently been established between moleculargraphbased structure descriptors of alkanes, in particular between (a) eigenvalue sum and Hosoya index, (b) greatest graph eigenvalue and connectivity index, (c) Wiener index and smallest positive Laplacian eigenvalue, (d) greatest Laplacian and greatest ordinary graph eigenvalue, (e) Zenkevich and Wiener index, and (f) hyperWiener and Wiener index. These all have been found to hold for alkanes with n=10 or fewer carbon atoms, and verified on samples consisting of all alkane isomers. Applying an algorithm for generating trees uniformly by random we have now tested these regularities for very large chemical trees (n=50). It has been found that regularities (c) and (f) hold equally well in the case of very large chemical trees, whereas regularities (a), (d) and (e) are applicable, but with significantly attenuated accuracy. Regularity (b) vanishes at large values of n.
Vol. 42A, June 2003, pp. 12461257
Anton Perdih
Mala vas 12, SI1000 Ljubljana, Slovenia
Received 2 December 2002
Topological indices Vj(1/2,1/2), Vj(1/2,1), Vij(1/4,1), Vij(1/4,1/3), Lj(1/3,1/4), Lij(1/4,1/2), lnMij(1/3,1/4), as well as lnMij( 4,1) are promising candidates for branching indices. The indices Vij(1/4,1.09) and lnMij(1.29,1), as well as lnMij( 3.59 : 1) have the best characteristics. Modification of summationderived indices using a root or a logarithm of the index values improves their characteristics only marginally. Using a logarithm of the index or the geometric mean of the value of the nondiagonal elements of the matrix among the multiplicationderived indices, improves the situation greatly, up to the level observed among summationderived indices. The values of indices Vj(1/2,1/2), Vij( 1/4,1), Vij( 1/4, 1/3), Lj(1/3,1/4), and Lij(1/4,1/2) increase with the size of the molecule as well as with branching. These indices belong to the branching indices of the BIM group.The value of the index lnMij(1/3,1/4) increases with the size of the molecule and decreases with branching, whereas the reverse is true for the index lnMij(1/3,1/4). These indices can be a good source to derive branching indices of the BIA group.
Vol. 42A, June 2003, pp. 12581263
Francisco Torrens
Institut Universitari de Ciència Molecular, Universitat de València, Dr. Moliner 50, E46100 Burjassot (València), Spain
Received 10 January 2003
This paper presents an application of plastic evolution to design a new chemical index (the coordination index, Ic) that permits molecular characterization. Ic is applied to homologous series of phenyl alcohols and 4alkylanilines, and compared to charge indices for dipole moment. The parameters needed to calculate Ic are minus the standard enthalpy of formation T, molecular surface area S and molecular weight W. The correlations between Ic, T, S, W and the number of C atoms in the alkyl chain indicate a homogeneous molecular structure of the phenyl alcohols and 4 alkylanilines.
Vol. 42A, June 2003, pp. 12641269
Douglas J Klein
Texas A & M University at Galveston, Galveston, Texas 775531675, USA
Received 1 February 2003
Different possible ways are noted to partition the socalled Wiener index of a molecular graph G into contributions associated to different substructures of G, particularly, for the case where G is a tree and the substructures are sites or bonds. Representative related partitionings for some related graph invariants are also established. Paralleling the definition of Wiener (or Hosoya) polynomials, the partitioning results are used to motivate Szeged polynomials.
Vol. 42A, June 2003, pp. 12701271
Andrey A. Dobrynin
Sobolev Institute of Mathematics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
Received 24 January 2003
The Wiener index ( ) is a structural descriptor of organic molecules. It is defined as the sum of distances between all vertices of a molecular graph. Some properties based on the decomposition of the Wiener index for catacondensed benzenoid graphs are presented. In particular, it is shown that if and only if , where denotes the sum of distances between vertices of degree 2 in a benzenoid graph .
Vol. 42A, June 2003, pp. 12721278
Ivan Gutman*, Dušica Vidović & Boris Furtula
Faculty of Science, University of Kragujevac, P.O.Box 60, YU34000 Kragujevac, Yugoslavia
Received 10 September 2002
Some further chemical applications of the Laplacian spectra are reported. The Kel'mans theorem for the calculation of the coefficients of the Laplacian characteristic polynomial is stated and exemplified. By means of this theorem a (previously known) formula for the Wiener and Kirchhoff index is deduced. It is shown that the Wiener index is correlated with the “algebraic connectivity”, namely, the smallest positive Laplacian eigenvalue. Lower and upper bounds for the Kirchhoff index are obtained.
Vol. 42A, June 2003, pp. 12791282
Bono Lučić, Ante Miličević, Sonja Nikolić & Nenad Trinajstić*
The Rugjer Bošković Institute, P.O. Box 180, HR10002 Zagreb, Croatia
Received 16 January 2003
A variable Wiener index vW, applicable only to acyclic structures, is defined as [n1(e) n2(e)] For the optimal exponentthat value of should be selected which gives the smallest standard error of estimate, s, in the structureproperty modeling. As a test case, the structureboiling point modeling of isomeric octanes is used. It is found that the optimal exponent is =1/3 which gives a twoparameter model with the lowest value of s (0.72C) of all tested models. Close to this model is a twoparameter model based on the variable Wiener index with exponent =1/3 (s=0.83C). Among the published models, only four and fiveparameter models, based on the overall connectivity indices, produce lower values of s (0.71C, 0.55C).
Vol. 42A, June 2003, pp. 12831294
Mircea V Diudea*
Faculty of Chemistry and Chemical Engineering, BabesBolyai University, 3400 Cluj, Romania
and
Oleg Ursu
Department of Chemistry, Cleveland State University 2121 Euclid Avenue, Cleveland, Ohio 44115, USA
Received 19 November 2002
Several topological indices–numerical descriptors encoding topological attributes of a molecular graph have been used both in graph discriminating analysis and correlating studies for modeling of a variety physicochemical properties and biological activities. However, only few software packages, viz., CODESSA, MOLCONN Z, Dragon, TOSS MODE and POLLY, are available for calculating topological indices. These incorporate correlating analysis statistics, as well. The TOPOCLUJ software package is designed to calculate topological descriptors from topological matrices and/or polynomials. Several weighting schemes including group electronegativity, group mass and partial charges are proposed. Topological indices derived from the matrices like adjacency, connectivity, distance, detour, distancepath, detourpath, Cluj, their reciprocal matrices, walkmatrices, walkoperated matrices, layer and shellmatrices have been successfully used in correlating studies and graph discriminating analysis during the last decade. Several novel topological matrices, like distancepath, Cluj (with its variants), layermatrices, walk matrix, walk (triple matrix) operator, characteristic and "property" polynomials, and the corresponding topological descriptors may be calculated by the TOPOCLUJ software package.
Vol. 42A, June 2003, pp. 12951297
Lemi Türker
Middle east Technical University, Department of Chemistry, 06531, Ankara, Turkey
Received 17 September 2002
Starting with the concept of T(A) graphs for alternant hydrocarbons, a novel topological index is defined. The index differentiates isomeric as well as isospectral molecules very well. The index is applicable to saturated or unsaturated systems and can be extended to heteroatom containing structures.
Vol. 42A, June 2003, pp. 12981303
Wai Chee Shiu1, Peter Che Bor Lam1 & Lianzhu Zhang2
1Department of Mathematics, Hong Kong Baptist University, 224 Waterloo Road, Kowloon Tong, Hong Kong.
2Department of Mathematics, Zhangzhou Teachers College, Zhangzhou, Fujian 363000, China
Received 25 November 2002
Let G be a molecular graph with characteristic polynomial . The leading eigenvalue of G is the largest root of the equation . In this paper, the hexagonal chain (unbranched catacondensed benzenoid molecule) with minimum leading eigenvalue among fully angular hexagonal chains having a given number of hexagons is determined
Vol. 42A, June 2003, pp. 13041308
Svetlana Marković
Faculty of Science, University of Kragujevac, P.O.B. 60, YU34000 Kragujevac, Yugoslavia
Received 24 January 2003
The total pielectron energy of phenylenes is approximated by means of a linear combination of the first few spectral moments of both molecular and line graphs. The two sets of moments produce very similar results, with very high accuracy. It is found that over 99.8% of the HMO total pielectron energy of phenylenes is determined by the number of carbon atoms. Number of bay regions plays a significant role in the dependence of E on molecular topology of phenylenes
Vol. 42A, June 2003, pp. 13091311
Ivan Gutman, Dušica Vidović, Nataša Cmiljanović, Svetlana Milosavljević & Slavko Radenković
Faculty of Science, University of Kragujevac, P.O.Box 60, YU34000 Kragujevac, Serbia & Montenegro
Received 27 January 2003
The energy E(G) of a graph G is, by definition, equal to the sum of absolute values of the eigenvalues of G. The motivation for such a definition comes from molecular orbital theory, where E(G) pertains to the total electron energy of the conjugated hydrocarbon whose molecular graph is G. However, E(G) is a welldefined quantity for all graphs. It has been shown that E(G) serves as a structuredescriptor in the case of saturated, electron, systems. The correlations of various physicochemical properties of alkanes with E(G) are found to be of similar quality as the correlations with other traditionally employed molecular structuredescriptors (Wiener and connectivity indices).
Vol. 42A, June 2003, pp. 13151329
Ernesto Estrada1,*, Grace Patlewicz & Eugenio Uriarte2
1Safety and Environmental Assurance Centre (SEAC), Unilever R&D, Colworth House, Sharnbrook,
Bedford MK44 1LQ, UK
2Faculty of Pharmacy, Department of Organic Chemistry, University of Santiago de Compostela,
15706 Santiago de Compostela, Spain
Received 28 January 2003
A review on the use of topological indices (TIs) in the process of drug design and development is presented on the basis of the most recent advances in this field. The first part of this work is focussed on introducing the definitions of terms used in drug design and discovery, graphtheoretical chemistry as well as topological indices. The second part of the review discusses the use of topological indices in the lead discovery and optimization processes, including similarity/dissimilarity studies, rational combinatorial library design, QSAR, the issue of 2D versus 3D QSAR, as well as the use of novel chemometric techniques, such as artificial neural networks, genetic algorithms and partial least squares in combination with TIs. Recent advances on the definition of TIs accounting for three dimensional molecular features (topographic indices) and molecular chirality are also presented.
Vol. 42A, June 2003, pp. 13301346
Ramanathan Natarajan*, Palanichamy Kamalakanan & Inderjit Nirdosh
Department of Chemical Engineering, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1
Received 8 January 2003
Topological indices (TI) are extensively used as molecular descriptors in building Quantitative StructureActivity Relationships (QSAR), Quantitative StructureProperty Relationships (QSPR) and Quantitative StructureToxicity Relationships (QSTR). We have applied the QSAR approach for the first time to froth flotation and modelled the separation efficiencies (Es) of four series of collectors namely, cupferrons, oaminothiophenols, mercaptobenzothiozoles and arylhydroxamic acids used for the beneficiation of uranium, lead, zinc and copper ores, respectively. Principal components extracted from topological indices are found to form linear regression equations that can predict the separation efficiencies of the first three classes of collectors. Inclusion of substituent constant or quantum mechanical parameters did not improve the fit and this may be due to the absence of large variation in electronic effects among the molecules in each class. A quadratic fit has been obtained instead of linear regression in the case of arylhydroxamic acids. The separation efficiencies of the members have been predicted within experimental error (5%) by the best regression equations in each series. From the statistical models built, it may be generalized that Es = f(TI). To extend the applications of TI in the field of mineral processing, a similarity space of 587 arylhydroxamic acids has been constructed using principal components extracted from Tis. Ten compounds have been selected for synthesis and testing. The approach appears to provide an efficient scientific tool for the selection of collectors from a virtual database and may lead to an inexpensive and quick method for the identification of new collectors.
Vol. 42A, June 2003, pp. 13471353
Lionello Pogliani
Dipartimento di Chimica, Università della Calabria, 87030 Rende (CS), Italy.
Received 23 January 2003
Odd complete graphs have been used to encode the innercore electrons of atoms with principal quantum number n 2. An algorithm based on this conjecture has been used to derive a set of connectivity basis indices that have been used to model the molecular polarizabilities of a set of fifty four organic compounds, and the rates of hydrogen abstraction of a set of twenty two phenethylamines. The model of the first property is very good, and the model of the second property is satisfactory. The basis indices used for modeling allow an interesting interpretation of the obtained results.
Vol. 42A, June 2003, pp. 13541359
Pablo Duchowicz1, Rómulo G. Siñani2, Eduardo A Castro1* & Andrey A Toropov3
1CEQUINOR, Departamento de Química, Facultad de Ciencias Exactas, Universidad, Nacional de La Plata, Calles 47 y 115, C.C. 962, La Plata 1900, Argentina
2Vostok Innovation Company, Azimstreet 4, Tashkent 700047, Uzbekistan
3Departamento de Química, Universidad Mayor de San Andrés, Campus Universitario, Calle 27 CotaCota, La Paz, Bolivia
Received 29 August 2002
The Gibbs free energy for a set of 60 hydrocarbons is calculated on the basis of topological indices defined from the distance and detour matrices within the realm of the QSPR theory. Linear and nonlinear polynomials fittings are performed and the results demonstrate the need to resort to higherorder regression functions in order to obtain better agreements between theoretical results and experimental thermodynamics data. Topological indices calculated from detour matrix yield rather satisfactory predictions of Gibbs free energy for hydrocarbons.
Vol. 42A, June 2003, pp. 13601367
Alina Pyka* & Katarzyna Bober
Silesian Academy of Medicine, Faculty of Pharmacy, Department of Analytical Chemistry,
4 Jagiellonska Street, 41200 Sosnowiec, Poland
Received 24 January, 2003
Homologous series of saturated fatty acids, from ethanoic to octadecanoic, have been characterized by selected structural descriptors based on distance matrix, adjacency matrix, information theory as well as electrotopological states. Fatty acids, from pentanoic to octadecanoic have been separated by means of RPHPTLC, on plates RP18 with and without concentrating zone, using mobile phases methanolwater, ethanolwater and npropanolwater in volume ratio 100:0, 95:5 as well as 90:10. The relationships existing between molar volume (Vm) and structural descriptors or RM values (obtained by means of RPHPTLC) of saturated fatty acids have been investigated. Comparison and estimation of usefulness of structural descriptors selected and RM values for calculating and predicting of molar volume of saturated fatty acids, from ethanoic to octanoic, is presented. It is stated that both structural descriptors and RM values can serve for calculating and predicting the molar volume of fatty acids investigated, but the selected traditional structural descriptors better described the molar volume than the RM values.
Vol. 42A, June 2003, pp. 13681378
Mihaela Căprioară* & Mircea V Diudea
Faculty of Chemistry and Chemical Engineering, BabesBolyai University, 3400 Cluj, Romania
Received 19 November 2002
Polychlorinated aromatic compounds viz., dibenzofurans (PCDFs), dibenzopdioxins (PCDDs) and biphenyls (PCBs) have been characterized on the basis of topological descriptors. A quantitative structureactivity relationship (QSAR) study is performed in order to emphasize the relation between some topochemical and electronic parameters and their binding affinity to the aryl hydrocarbon receptor (AhR). The models reveal that the main feature influencing the binding activity of these compounds is a partial chargebased descriptor, a measure of the molecular electronic properties derived using the correlation weights of these local invariants. The linear regression equations enables to predict correctly the binding affinity of the polychlorinated derivatives. The present model shows good agreement with literature data.
Vol. 42A, June 2003, pp. 13791384
Vinod K Sharma*, Romi & Satish Kumar
Department of Chemistry, Maharshi Dayanand University Rohtak 124 001, India
Received 31 January 2003
Speed of sound U, of 1,3dioxolane (i) + toluene (j) or + o or + pxylene (j) binary and 1,3dioxolane (i) + toluene (j) + o or + pxylene(k) ternary mixtures have been measured over the whole mole fraction range at 298.15 K. Excess isentropic compressibility, KSE values have been calculated employing density, ij and ijk speed of sound values of the binary and ternary mixtures. The KSE values for the binary and ternary mixtures have also been evaluated by employing graph theory. It has been observed that KSE values predicted by graph theoretical approach compare reasonably well with the KSE values determined from experimental data.
Vol. 42A, June 2003, pp. 13851391
Subhash C Basaka*, Denise Millsa, Moiz Mumtazb & Krishnan Balasubramanianc
a Natural Resources Research Institute, University of Minnesota Duluth, 5013 Miller Trunk Highway, Duluth, MN 55811, USA
b Computational Toxicology Laboratory, Division of Toxicology, Agency for Toxic Substances and Disease Registry (ATSDR), Executive Park Building 4, 1600 Clifton Road, E29, Atlanta, GA 30333, USA
c Department of Applied Sciences, University of California Davis, Hertz Hall, L794 Livermore, CA 94550, Chemistry &
Material Science Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550 and
Glenn T. Seaborg Center, Lawrence Berkeley National Laboratory, Berkeley CA 94720
Received 1 February 2003
Topostructural (TS) and topochemical (TC) indices, geometrical descriptors, and ab initio (STO3G) quantum chemical indices have been employed either alone or hierarchically in the development of quantitative structureactivity relationship (QSAR) models of the aryl hydrocarbon (Ah) receptor binding potency of a set of 34 dibenzofurans. Results show that, for the full set, the TS and TC indices explain most of the variance in the data. The addition of 3D and quantum chemical indices make only slight improvement in the predictive capability of QSAR models.
Vol. 42A, June 2003, pp. 13921404
Jesus Vicente de JuliánOrtiz1, Emili Besalú*1,2, Ramón GarcíaDomenech3
1Institut de Química Computacional. Universitat de Girona. Spain
2Departament de Química. Universitat de Girona. Spain
3Unidad de Investigación de Diseño de Fármacos y Conectividad Molecular. Universitat de València. Spain.
Received 11 February 2003
A set of 21 previously published COX2 inhibitors has been analyzed in order to obtain a new paradigm capable of obtaining true predictions of the activity. Overfitting in the models has effectively been prevented even for small training sets. The most significant variables for the prediction of the property have been selected, and outliers have also been easily identified with this approach. Topological indices have been used as descriptors.
Vol. 42A, June 2003, pp. 14051413
Alina Pyka1*, Elzbieta Kępczyńska2 & Jacek Bojarski2
1Silesian Academy of Medicine, Faculty of Pharmacy, Department of Analytical Chemistry,
4 Jagiellońska Street, 41200 Sosnowiec, Poland
2Medical College of Jagiellonian University, Department of Organic Chemistry, 9 Medyczna Street, 30688 Kraków, Poland
Received 24 January, 2003
Thirteen barbiturates have been separated by reversedphase thin layer chromatography with thirteen mobile phases. The RM values of barbiturates investigated have been correlated with the selected traditional structural descriptors, with the partition coefficients of the compounds, and with the dipole moments (mph) or with the permittivities (mph) of the mobile phases applied. The most accurate prediction of the RM values of the barbiturates in all the mobile phases investigated, have been achieved by use of twoparametric equation employing the dipole moments (or the permittivities) of the mobile phases, and one topological indices from among the topological indices o, 1, o, 1, R, W, A, 1B and three parametric equations employing the dipole moments (or the permittivities) of the mobile phases, and two topological indices (IB and 1 as well as IB and 1), or one electrotopological descriptor (SdssC or SssssC) or Gutman index (M or M), and selected partition coefficient. However, Randić indices of 0order (o and o) are the most universal for QSAR analysis of barbiturates investigated.
Vol. 42A, June 2003, pp. 14141425
Sunil Gupta1, Manjeet Singh1 & Anil Kumar Madan*2
1 Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147 002, India
2 Faculty of Pharmaceutical Sciences, M.D. University, Rohtak 124 001, India
Received 29 December 2002
The discriminating power of three novel adjacencycumdistance based chemical topological descriptors termed as eccentricadjacency topochemical indices have been investigated to estimate antiHIV activity of 107 derivatives of 6(phenylthio)thymines. The values of eccentricadjacency topochemical indices of each derivative in the dataset have been computed and suitable models developed after identification of the active ranges. Subsequently, each derivative has been assigned a biological activity which was then compared with the reported antiHIV activity. The use of models based upon these topochemical indices result in prediction of antiHIV activity with an accuracy of 8189 %. An excellent relationship between eccentricadjacency topochemical indices and antiHIV activity of 6(phenylthio) thymine derivatives can be attributed to sensitivity of the proposed topochemical indices towards nature, number and relative position of heteroatoms. The high discriminating power of eccentricadjacency topochemical indices along with other mathematical tools can be exploited for drug design.
Vol. 42A, June 2003, pp. 14261435
Vijay K Agrawala*, Sneha Karmarkar b, Padmakar V Khadikar b & Shachi Shrivastavaa
a QSAR and Computer Chemical Laboratories, APS University, Rewa 486 003, India,
email: vijayagrawal@lycos.com
bResearch Division, Laxmi Fumigation and Pest Control Pvt. Ltd., 3 Khatipura, Indore 452 007, India.
and
Istavan Lukovits
Chemical Research Center,Hungarian Academy of Sciences, H1525 Budapest P.O.B. 17, Hungary
Received 31 October 2002
This paper describes topological modeling of antihypertensive activity of 2aryliminoimidazolidines. A large pool of distancebased topological indices consisting of W, B, , J, Sz, and log RB is initially used for this purpose. An excellent model is obtained in multiparametric regression containing and logRB along with two indicator parameters
Vol. 42A, June 2003, pp. 14361441
Padmakar V.Khadikar1,*, Istvan Lukovits2, Vijay K.Agrawal3, Shachi Shrivastava3’, Mona Jaiswal4,
Ivan Gutman5 , Sneha Karmarkar1 & Anjali Shrivastava4
1Research Division, Laxmi Fumigation & Pest Control (P), 3,Khatipura, Indore 452 007, India
*Email: pvkhadikar@rediffmail.com
2Chemical Research Center, Hungarian Academy of Sciences, H1525 Budapest, P. O. Box 17, Hungary
3QSAR & Computer Chemical Laboratories, A.P.S. University, Rewa 486 003, India
4Department of Chemistry, Govt. Model and Autonomous Holkar College, Indore 452 001, India
5Faculty of Science, University of Kragujevac, P. O. Box 60, YU34000 Kragujevac, Serbia & Montenegro
Received 6 January 2003
Use of equalized electronegativity (eq) in modeling toxicity of nitrobenzene is discussed. Results show that more reliable models can be obtained when eq is combined with topological indices. The results are discussed by using multiple regression and crossvalidation procedures.
Vol. 42A, June 2003, pp. 14421445
Lemi Türker
Middle East Technical University, Department of Chemistry, 06531, Ankara, Turkey
Recieved 9 September 2002
A vector model based on the truncated Hosoya indices has been introduced. Two novel indices (cos and T) are proposed and used for a series of compounds that had been tested previously on Galleria mellonella L. females as sexattractants. The model also enables to visualize better the relationship between the property/activity and structure (the Hosoya indices).