Optimizacija sinteze i in vitro proučavanje antimikrobnog dejstva α,β-nezasićenih i α-bromkarboksilnih kiselina

A series of α,β-unsaturated and α-bromo carboxylic acids were identified as potent antimicrobial agents. The antimicrobial activity was evaluated using the broth microdilution method. All acids 1-12 exhibited a significant activity against nine laboratory control strains of bacteria and two strains of yeast Candida albicans. The tested acids were efficiently prepared by optimized phase-transfer-catalyzed (PTC) reactions of ketones with bromoform and aqueous lithium hydroxide in alcoholic solvent with triethylbenzyl ammonium chloride (TEBA) as catalyst.U ovom radu je prikazano in vitro ispitivanje antimikrobnog dejstva serije α,β-nezasićenih i α-bromkarboksilnih kiselina i pokazano je da su one potencijalno dobri antimikrobni agensi. Sve kiseline 1-12 pokazale su značajnu aktivnost prema devet sojeva bakterija i dva soja gljivica Candida albicans. Ispitivane kiseline sintetisane su u optimizovanoj reakciji ketona sa bromoformom i litijum-hidroksidom u smesi rastvarača (terc-butanol/voda). Kao katalizator za prenos između faza upotrebljen je trietilbenzilamonijum-hlorid (TEBA)

Spectroscopic and quantum chemical elucidation of newly synthesized 1-aryl-3-methyl-3-phenylpyrrolidine-2,5-diones as potential anticonvulsant agents

Novel succinimide derivatives were synthesized from 3-methyl-3-phenylsuccinic acid and substituted anilines under solvent-free conditions by using microwave irradiation. All obtained compounds were characterized by ultraviolet (UV), Fourier-transform infrared (FT-IR), H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy as well as by elemental analysis. The influence of the substituent electronic effects on spectroscopic data was analyzed by applying the Hammett equation. Moreover, a detailed interpretation and comparison of experimentally obtained and theoretically calculated FT-IR, UV and NMR spectra was performed. Density functional theory (DFT) calculated data of the investigated succinimides were obtained and analyzed in order to determine their structural, spectroscopic and electronic properties. Furthermore, ADMET factor profiling and in-silico prediction of potential biological activities of novel succinimide derivatives have been performed

Voltammetric and Quantum Investigation of Selected Succinimides

A series of succinimide derivatives were studied using the cyclic and square wave voltammetry. Density function theory was used in order to determinate which of the structural parameters influence the electrochemical activity. The quantum chemical calculations of the investigated succinimides were linked with the experimental electrochemical data and used to propose the oxidation mechanism. The most active among studied succinimides is 1,3-diphenylsuccinimide. The results obtained from the cyclic and square wave voltammetry and quantum chemical calculations indicate that the investigated compounds undergo oxidation by irreversible, diffusion controlled process including transfer of 1e(-) and 1 proton. The voltammetric and DFT results signify that the mechanism of electrochemical oxidation of all compounds involve the conversion of carbonyl-methyne-phenyl segment or methylene group in free radical. This conversion proceeds by the loss of one proton one electron process

Absorption and fluorescence spectral properties of azo dyes based on 3-amido-6-hydroxy-4-methyl-2-pyridone: Solvent and substituent effects

A series of nine 5-(4-substituted phenylazo)-3-amido-6-hydroxy-4-methyl-2-pyridones were synthesized and characterized by FT–IR, 1H and 13C NMR, UV–Vis, and PL spectroscopy. Photophysical properties of the dyes were examined in solvents of various polarities and at different pH values. The solvent effects on the absorbance and emission spectral shift were analyzed using Lippert–Mataga, Reichardt–Dimroth and Kamlet-Taft equations. Moreover, UV–Vis absorption and emission frequencies were correlated with Hammett substituent constants applying the linear free energy relationships. DFT calculations of the investigated dyes were accomplished to determine their structural and electronic properties. © 201

Synthesis, antimicrobial activity and quantum chemical investigation of novel succinimide derivatives

In the present study, twelve new 1-aryl-3-ethyl-3-methylpyrrolidine-2,5-diones were synthesized and their structures were characterized by FT-IR, H-1 NMR, C-13 NMR spectroscopy and elemental analysis. In the final step of synthetic rout, condensation between corresponding succinic acid and substituted anilines has been improved using the microwave irradiation. Significantly higher yields compared to conventional condensation have been observed. The preliminary biological results indicated that some of the synthesized compounds showed promising in vitro antifungal activities towards several test fungi. 1-(4-Bromophenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione (8) exhibited significant in vitro inhibitory activities against broad spectra of fungus, and on the basis of obtained data, the investigated bromo derivative has to be observed as novel potential fungicide. The density functional theory (DFT) calculations have been performed in order to study the structure-activity relationship (SAR) of the investigated molecules. In order to prediction of the chemical activity of the molecule, the molecular electrostatic potential (MEP) map was analyzed for the optimized geometry of 1-phenyl-3-ethyl-3-methylpyrrolidine-2,5-dione (4) and 1-(4-bromophenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione (8)

Synthesis, UV-Vis spectrophotometric titration and theoretical calculations of 6-hydroxy-4-methyl-3-(pyridinium-1-yl)-2-pyridone

U ovom radu prikazana je sinteza i karakterizacija 6-hidroksi-4-metil-3-(piridinijum-1-il)-2-piridona. Sintetisano jedinjenje dobijeno je u obliku dipol-jona. Spektrofotometrijskom titracijom u rastvoru etanola ispitan je uticaj pH vrijednosti na strukturu jedinjenja. Kako bi se detaljno opisala struktura derivata 2-piridona, eksperimentalno dobijene vrijednosti dobijenih apsorpcionih maksimuma upoređeni su sa kvantno-hemijskim proračunima optimizovanih geometrija i teorijskih UV-Vis spektara pri različitim pH vrijednostima.In this research, synthesis and characterization of 6-hydroxy-4-methyl-3-(pyridinium-1-yl)-2-pyridone was shown. Synthesized compound was achieved in the zwitterionic form. UV-Vis spectrophotometric titration was performed in order to examine the influence of pH values on the structure of the compound. For the purpose of detail characterization of 2-pyridone derivative, experimentally obtained results were compared to quantum-chemical calculations of optimized geometries and theoretical UV-Vis spectra of solution for different pH values

Determination of all pK(a) values of some di- and tri-carboxylic unsaturated and epoxy acids and their polylinear correlation with the carboxylic group atomic charges

For a series of seven unsaturated and seven epoxy di- and tricarboxylic acids, pK(a)(a) values were determined potentiometrically in aqueous media at 25 degreesC and an ionic strength of 0.1 M (NaCl). The thermodynamic pKaa values were correlated with the atomic charges of carboxylic group calculated by the MNDO-PM3 semiempirical MO method

Computational and spectroscopic data correlation study of N,N '-bisarylmalonamides (Part II)

To complement a previous UV study, we present a quantitative evaluation of substituent effects on spectroscopic data (H-1 and C-13 NMR chemical shifts as well as FT-IR absorption frequency) applied to N, N'-bisarylmalonamides, using simple and extended Hammett equations as well as the Swain-Lupton equation. Furthermore, the DFT CAM-B3LYP/6-311+G(d,p) method was applied to study the impact of different solvents on the geometry of the molecules and their spectral data. Additionally, experimental data are correlated with theoretical results; excellent linear dependence was obtained. The overall results presented in this paper show that N, N'-bisarylmalonamides are prominent candidates for model molecules

Solvatochromic and quantum chemical investigations of newly synthesized succinimides: substituent effect on intramolecular charge transfer

Two series of 1-aryl-3-phenyl- and 1-aryl-3,3-diphenylpyrrolidine-2,5-diones were synthesized and their solvatochromic properties were studied in a set of 15 solvents of different polarity. The effect of specific and non-specific solvent-solute interactions on the position of their absorption bands was evaluated by using the solvent parameter sets of Kamlet and Taft. The interpretation of the effect of different substituent patterns on the solvatochromic properties of the investigated compounds was based on quantum chemical calculations performed by the density functional theory (DFT)/CAM-B3LYP method using the 6-311G(d,p) basis set. The theoretical absorption frequencies show very good agreement with the experimental values. The energy gaps between the HOMO and LUMO orbitals were also analyzed. It is demonstrated that different substituents change the conjugation effect and further determine the pathways of intramolecular charge transfer