Antimitotic agents prevent the mitosis process of cell cycle and are generally used for the treatment of cancer with good clinical success. QSAR analysis was performed on 33 reported 2-phenylindole-3-carbaldehyde derivatives to find out the structural requirements of these compounds for higher antimitotic activity. The dataset was divided into test set and training set by k-MCA. Factor analysis-stepwise multiple linear regression (FA-sMLR) method was used to develop statistically significant QSAR equations. QSAR analysis showed importance of topological indices like RTSA indices, structural information content indices, Balaban-type index from van der Waals weighted distance matrix Jhetv, rotatable bond fraction RBF, and Lovasz-Pelikan index LP1 on biological activity. The study also shows significance of electrostatic potential charges of different atoms as well as principal moment of inertia along Y axis and number of nitrogen atoms toward antimitotic activity of these compounds. © 2009 John Wiley & Sons A/S.

Molecular dynamics simulations of self-assembled monolayers (SAMs) of alkanethiol derivatives interfaced with water reveal the structure of the interface and show how it influences the properties of water. Three SAMs of different character (neutral, anionic and cationic) are compared: 6-hexanethiol, 11-mercaptoundecanoic acid and 11-amino-1-undecanethiol. The simulation captures phenomena such as the hydrophobic gap, local increase of the density of water near the interface and ordering of water into layers.

Based on our earlier QSAR study, a series of 1, 5-N,N′-substituted-2-(substituted naphthalenesulphonyl) glutamamides were synthesized as possible anticancer agents. Anticancer activities of these synthesized compounds were evaluated in vivo on Swiss Albino mice against Ehrlich Ascites Carcinoma (EAC) cells where inhibitions of tumor cell and tumor weight were considered as biological activity parameters. A comparative QSAR study was done with a set of descriptors and logarithm of tumor cell inhibition. The result shows the importance of topological parameters like ETSA and RTSA indices as well as electronic parameter like Wang-Ford charges of different atoms. Electrophilic attack at atom number 5 and increased number of chlorine atom may be favorable whereas presence of methoxy group at the atom number 8 in naphthalene ring may be detrimental to the activity.

Although a great variety of classical force fields (FFs) for room-temperature ionic liquids (RTTLs) have been recently suggested, no systematically derived non-polarizable model is able to reproduce their transport properties, i.e. diffusion constants, conductivities and viscosities. In the present paper, we show that modern FFs greatly overestimate pairwise electrostatic interaction energies in the RTILs systems leading to extremely hindered ionic motions. Based on the results of our ab initio molecular dynamics calculations using explicit ionic environment, we modified the electrostatic interaction potential of 1-ethyl-3-methylimidazolium tetrafluoroborate. Starting from FF, originally derived by Liu et al., we further refined it, so that it reproduces experimental transport properties without compromizing either structure or thermodynamics. The main advantages of the suggested phenomenological account for electronic polarization are its consistency, clearness, simplicity and the possibility to improve functionality of the existing FFs by modifying exclusively atomic partial electrostatic charges. ©The Electrochemical Society.

A qualitative and quantitative energetic and structural study of dibenzyl ketone (DBK) and benzyl ethyl ketone (BEK) was carried out in order to obtain insights into the type and magnitude of aromatic interactions that these systems present in their different phases. The crystal structure of DBK was obtained by X-ray crystallography, and it shows that the conformation adopted in the crystalline state is governed by the intermolecular interactions. The standard (p(0) = 10(5) Pa) molar enthalpy of formation in the gaseous state at T = 298.15 K was derived by Calvet and combustion calorimetry. Using a homodesmic reaction scheme, the first calorimetric evaluation of the interaction enthalpy between two stacked phenyl rings is presented. A stabilizing enthalpic effect of (12.9 +/- 4.9) kJ mol(-1) associated with the intramolecular pi-pi interaction in DBK was found. The gas phase intramolecular pi ... pi interaction in DBK is in agreement with quantum chemical calculations at B3LYP/6-311++ G(d, p) and MP2 with various basis-sets. An intramolecular pi ... pi interaction in DBK and a weak C-H ... pi interaction in BEK were found by variable-temperature (1)H-NMR spectroscopy in MeOD. These observations are consistent with a hindered rotor interpretation, supported by ab initio calculations for the gas phase at the MP2/cc-pVDZ level. The global results indicate a distinct molecular structure on going from crystalline DBK to liquid, gas, and solution phases, ruled by the overall contribution of the intra- and intermolecular interactions.

The conformational preferences of morphine and heroin were studied in gas phase and with inclusion of solvent effects. At 298.15 K, three conformers are significant for isolated morphine, all of them displaying antiperiplanar arrangement for the C2-C3-O-H unit, and there is only one significantly populated conformer for heroin. Quantum theory of atoms in molecules analysis of the electron density in their most populated conformers in gas phase indicates that the positive charge is shared among the amino hydrogen, those hydrogens of the methylamino group, and all of the hydrogens attached to the bridgehead carbons. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110: 2472-2482, 2010