Prediction of the logarithmic of partition coefficients (log P) of some organic compounds by least square-support vector machine (LS-SVM)

Theoretical Study of the Relationship Between Wiener, Padmakar-Ivan, and Szeged Topological Indices in Contrast to Energy, Electric Moments and Partition Coefficient of Armchair Polyhex Carbon Nanotubes with Various Circumference and Fixed Lengths

“…Tables 1, 2 and 3 show the different calculated values of the polyhex carbon nanotube TUVC 6 [2p, q] with various circumferences [2p] and fixed length [q]. As can be seen, with an increase in the carbon number of nanotubes, the values of energy (kJmol −1 ), electric quadrupole, hexadecapole moments and their logarithmic values of armchair polyhex carbon nanotube TUVC 6 [2p, q] with q: 3, p: (3,4,5,6,7,8,9,10,11,12,13) or (C 18 , C 24 , C 30 , C 36 , C 42 , C 48 , C 54 , C 60 , C 66 , C 72 , C 78 ) are increased. Therefore, it can be concluded that the number of carbon atoms in a nanotube would affect its energy.…”

“…Two of these correspond to high symmetry SWNTs; in zigzag tubes, some of the C-C bonds lie parallel to the tube axis, while in armchair tubes, some bonds are perpendicular to the axis (Scheme 1). Recently, researchers In this study, the relationship between Wiener, Padmakar-Ivan, Szeged topological indices and partition coefficient (Log P) in contrast to the electric moments and energy (kJmol −1 ) of some armchair polyhex carbon nanotubes TUVC 6 [2p,q] with various circumference [p: 3,4,5,6,7,8,9,10,11,12,13] and fixed lengths [q: 3] are represented. The quantum chemical descriptors and optimized geometrical structure are obtained by Becke's three-parameter formulation with the Lee-Yang-Parr functional (B3LYP) level and the 3-21G standard basis set.…”

Feature selection method based on fuzzy entropy for regression in QSAR studies

“…It is well known that quantitative structure-activity/ property relationships (QSAR/QSPR) are one of the most successful approaches to predicting chemical properties starting only with molecular structural information, that play crucial roles in the elucidation of drug action mechanisms and the design of more potent drugs [1][2][3][4]. The predictability of such a QSAR/ QSPR model is affected by two factors.…”

QSAR prediction of HIV inhibition activity of styrylquinoline derivatives by genetic algorithm coupled with multiple linear regressions

“…The major goal of quantitative structure-activity/property relationship (QSAR/QSPR) studies is to relate the biological activity of a series of compounds with some appropriate descriptors (Goodarzi and Freitas, 2008a, b, c;Freitas et al, 2008;Fatemi and Goudarzi, 2005;Goudarzi and Goodarzi, 2008). The predictive accuracy of QSAR is typically affected by two aspects: the selection of descriptors that sufficiently represent the structural information, and the choice of a specific predictive model.…”

“…The pIC 50 value for each molecule would then be calculated as a composite of each molecular descriptor weighted by the respective coefficients. Also, least-squares procedures are widely used for estimating parameters/coefficients in MLR and other model equations (Goudarzi and Goodarzi, 2008).…”