Search results for "derivati"

Synthesis, Characterization, Thermal and Antimicrobial studies of N-substituted Sulfanilamide derivatives

2014

Abstract Four sulfanilamide derivatives N -[4-(phenylsulfamoyl)phenyl]acetamide (1), 4-amino- N -phenylbenzenesulfonamide (2), N -[4-(phenylsulfamoyl)phenyl]benzamide (3) and N -{4-[(3-chlorophenyl)sulfamoyl]phenylbenzamide (4) were synthesized and characterized by Infra-Red (IR), Nuclear Magnetic Resonance (NMR) and UV–visible (UV–Vis) spectra. Also Liquid Chromatographic (LCMS) and High Resolution Mass Spectrometric (HRMS) methods were used. Crystal structures of 1–4 were determined by single crystal X-ray diffraction (XRD) and their conformational and hydrogen bond (HB) network properties were examined with survey of the literature data. Compounds 1 and 2 crystallize in the same orthorho…

Supramolecular Construction of Cyanide-Bridged Re I Diimine Multichromophores

2019

The reactions of labile [Re(diimine)(CO)3(H2O)]+ precursors (diimine = 2,2′-bipyridine, bpy; 1,10-phenanthroline, phen) with dicyanoargentate anion produce the dirhenium cyanide-bridged compounds [{Re(diimine)(CO)3}2CN)]+ (1 and 2). Substitution of the axial carbonyl ligands in 2 for triphenylphosphine gives the derivative [{Re(phen)(CO)2(PPh3)}2CN]+ (3), while the employment of a neutral metalloligand [Au(PPh3)(CN)] affords heterobimetallic complex [{Re(phen)(CO)3}NCAu(PPh3)]+ (4). Furthermore, the utilization of [Au(CN)2]−, [Pt(CN)4]2–, and [Fe(CN)6]4–/3– cyanometallates leads to the higher nuclearity aggregates [{Re(diimine)(CO)3NC}xM]m+ (M = Au, x = 2, 5 and 6; Pt, x = 4, 7 and 8; Fe, x…

Perfil químico do extrato polar de Paepalanthus microphyllus(Guill.) Kunth (Eriocaulaceae)

2004

From the ethanolic extract of the capitulae of Paepalanthus microphyllus, one caffeic acid derivative (1) was isolated. The structure of the compound was characterized by spectroscopic methods, mainly 1D and 2D NMR experiments, as well as ESMS spectrometry. In addition, three flavonoids of taxonomic relevance were isolated and identified by comparison to literature data. Do extrato etanólico dos capítulos de Paepalanthus microphyllus, isolou-se um derivado do ácido cafeico (1). Sua estrutura foi caracterizada por métodos espectroscópicos (RMN mono e bi-dimensionais) e por espetrometria de massas Electrospray. Foram, também, isolados outros três flavonóides (2-4) de interesse taxonômico, os …

Influence of different biomaterials on the viability of Aggregatibacter actinomycetemcomitans

2011

Abstract Objectives The aim of the present in vitro study was to evaluate the effects of different biomaterials used for regenerative periodontal surgery on the growth of the periodontopathogen Aggregatibacter actinomycetemcomitans . Methods Three commercially available biomaterials of synthetic origin (hydroxyapatite/beta-tricalcium phosphate, nanostructured hydroxyapatite paste, oily calcium hydroxide suspension), a bovine-derived xenograft as well as an enamel matrix derivative (EMD) were added in different concentrations to calibrated suspensions of A. actinomycetemcomitans ATCC 43718/33384 (serotype b/c). Equal aliquots (0.1 ml) for the viability assay were taken after 5 min, 1 h, 3 h,…

Lower rim arylation of calix[n]arenes with extended perfluorinated domains

2006

Abstract Exhaustive O-arylation of p-tert -butylcalix[ n ]arenes 2 ( n  = 4–8) with an excess of 3-pentadecafluoroheptyl-5-pentafluorophenyl-1,2,4-oxadiazole 3 and K 2 CO 3 in refluxing acetonitrile provides an easy entry to a new family of perfluorinated calix[ n ]arenes 1 . The cyclic tetramer furnishes a mixture of cone , partial cone , and 1,2-alternate conformers, while the larger macrocycles afford single products. The structures of all new compounds are substantiated by NMR techniques and MALDI-TOF mass spectral data. Single-crystal X-ray diffraction studies on the pentamer derivative 1b reveal a distorted cone-in conformation of the calixarene cup.

Biological Evaluation of the Antiproliferative and Anti-migratory Activity of a Series of 3-(6-Phenylimidazo[2,1-b][1,3,4]thiadiazol-2-yl)-1H-indole …

2019

Heterocyclic rings are recognized as key components of many natural, semi-synthetic and synthetic molecules with a broad spectrum of biological activities. Among these molecules, the indole and imidazo[2,1-b][1,3,4]thiadiazole systems have recently been described as useful scaffolds for the design of anticancer agents. Herein the antitumor activity of a series of 3-(6-phenylimidazo[2,1-b][1,3,4]thiadiazol-2-yl)-1H-indoles, designed as hybrid structures, was assessed. Seven out of 10 compounds (1a-g) were submitted to National Cancer Institute (NCI). Remarkably, compound 1g showed antiproliferative activity against the full panel of sixty human cancer lines, with half-maximal inhibitory conc…

Infinitely many solutions to boundary value problem for fractional differential equations

2018

Variational methods and critical point theorems are used to discuss existence of infinitely many solutions to boundary value problem for fractional order differential equations where Riemann-Liouville fractional derivatives and Caputo fractional derivatives are used. An example is given to illustrate our result.

Application of the 6-aminoquinolyl-N-hydroxysccinimidyl carbamate (AQC) reagent to the RP-HPLC determination of amino acids in infant foods.

2005

The validation of a pre-column derivatization procedure with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) to the determination of the amino acid content by RP-HPLC with fluorescence detection (lambda excitation 250 nm, lambda emission 395 nm) in milk-cereal based infant foods was carried out. The analytical parameters: linearity (0.0025-0.2mM), precision of the method (0.2-3.5% variation coefficients), accuracy (derivatization: 86-106% average recovery and method: 88.3-118.2% average recovery) and the limits of detection (0.016-0.367 microM) and quantification (0.044-1.073 microM) were determined. Glutamic acid, proline and leucine were the most abundant amino acid whereas the lowe…

Recent Results of Studies on Dialkyltin(IV) Complexes of Acidic Derivatives of Carbohydrates

2008

DFT calculation of 1J(119Sn,13C) and 2J(119Sn,1H) coupling constants in di- and trimethyltin(IV) compounds

2008

We have tested several computational protocols, at the nonrelativistic DFT level of theory, for the calculation of 1J(119Sn, 13C) and 2J(119Sn, 1H) spin-spin coupling constants in di- and trimethyltin(IV) derivatives with various ligands. Quite a good agreement with experimental data has been found with several hybrid functionals and a double-zeta basis set for a set of molecules comprising tetra-, penta-, and hexa-coordinated tin(IV). Then, some of the protocols have been applied to the calculation of the 2J(119Sn, 1H) of the aquodimethyltin(IV) ion and dimethyltin(IV) complex with D-ribonic acid and to the calculation of 1J(119Sn, 13C) and 2J(119Sn, 1H) of the dimethyltin(IV)-glycylglycin…