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A quantitative structure-property relationship (QSPR) was developed for modeling the retention index of 1184 flavor and fragrance compounds measured using a Carbowax 20M glass capillary gas chromatography column. The 4885 molecular descriptors were calculated using Dragon software, and then were simultaneously analyzed through multivariable linear regression analysis using the replacement method (RM) variable subset selection technique. We proceeded in three steps, the first one by considering all descriptor blocks, the second one by excluding conformational descriptor blocks, and the last one by analyzing only 3D-descriptor families. The models were validated through an external test set of compounds. Cross-validation methods such as leave-one-out and leave-many-out were applied, together with Y-randomization and applicability domain analysis. The developed model was used to estimate the I of a set of 22 molecules. The results clearly suggest that 3D-descriptors do not offer relevant information for modeling the retention index, while a topological index such as the Randić-like index from reciprocal squared distance matrix has a high relevance for this purpose., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Five Schiff bases obtained from condensation of 4-methoxybenzohydrazide with related aldehydes, namely o-vanillin, vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde were prepared. A detailed structural and spectroscopic study is reported. The crystal structures of four members of the family were determined and compared with one another. The hydrazones obtained from 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde resulted to be isomorphic to each other. The solid-state structures are stabilized by intra-molecular O-H⋯N interactions in salicylaldehyde derivatives between the O-H moiety from the aldehyde and the hydrazone nitrogen atom. All crystals are further stabilized by inter-molecular H-bonds mediated by the crystallization water molecule. A comparative analysis between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. The structure is predicted for the compound for which the crystal structure was not determined. Infrared and electronic spectra were measured and assigned with the help of data obtained from computational methods based on the Density Functional Theory., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A detailed structural and spectroscopic study of the disulfide Schiff base obtained from condensation of 2-aminothiophenol and o-vanillin is reported. It includes the analyses of the anhydrous and monohydrate forms of the title compound. Structures of both solids were resolved by X-ray diffraction methods. A comparison between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. Vibrational (IR and Raman) and electronic spectra were measured and assigned with the help of computational methods based on the Density Functional Theory. Calculated MEP-derived atomic charges were calculated to predict coordination sites for metal complexes formation., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Mayor depression, obsessive-compulsive panic, social anxiety disorders are common diseases that are usually treated with sertraline hydrochloride which is the active ingredient of the well known drugs as Zoloft and Lustral. In this work, we presented a more complete vibrational characterization of the solid phase FT-IR spectra of Sertraline hydrochloride and its sertraline-iodine product in which the conformational space of the molecules was investigated performing molecular dynamic simulations within an NVT ensemble. Geometrical, electronic and vibrational properties were calculated with the density functional theory. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes of both molecules. In addition, for the first time we present the evaluation of anti-thyroid activity of sertraline hydrochloride by using the Lang's method. Also, with the aim to evaluate the antidepressant effect of its iodine product we demonstrated for this compound the toxic effect towards the male Wistar rats., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The conformational behavior of 2,3,4,6-tetra-O-acetyl-β-D-mannopyranosyl methanesulfonamide has been investigated from a combined theoretical and experimental point of view. The study of the conformational space of the glycosyl sulfonamide revealed that the β anomer is thermodynamically more stable than the α one. This fact suggests that the synthesis reaction could take place mainly under thermodynamic control as the main experimental product is the β-anomeric form of the sulfonamide. Several intramolecular hydrogen bonds were found in the stable conformers of the N-mannopyranosyl sulfonamide under study. A relationship was found to exist between them and the relative stability of the conformers. A detailed analysis of geometrical parameters shed light into the nature of the solid state structure of the novel 2,3,4,6-tetra-O-acetyl-β-D-mannopyranosyl methanesulfonamide in terms of exo- and endo-anomeric effects and antiperiplanar relationships. NBO calculations confirmed those findings. Calculated (1)H and (13)C NMR chemical shifts support previous findings concerning configuration and conformation assignments of the title sulfonamide. Finally, an explanation of the stereochemical outcome of sulfonamidoglycosylations, was given in terms of exo- and endo-anomeric effects and steric factors., (Copyright © 2012 Elsevier Ltd. All rights reserved.)