Search results for "Aniline Compound"
showing 10 items of 54 documents
Dependence of the Optical Constant Parameters of p-Toluene Sulfonic Acid-Doped Polyaniline and Its Composites on Dispersion Solvents
2020
The optical constants of Para-Toluene sulfonic acid-doped polyaniline (PANI), PANIchitosan composites, PANI-reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide dispersed in diluted p-toluene sulfonic acid (PTSA) solution and N-Methyl-2-Pyrrolidone (NMP) solvent have been evaluated and compared. The optical constant values were extracted from the absorbance spectra of thin layers of the respective samples. The potential utilization of the materials as the active sensing materials of surface plasmon resonance biosensors has also been assessed in terms of the estimated value of the penetration depth through a dielectric medium. The …
Nitroanilines as Quenchers of Pyrene Fluorescence
2012
The quenching of pyrene and 1‐methylpyrene fluorescence by nitroanilines (NAs), such as 2‐, 3‐, and 4‐nitroaniline (2‐NA, 3‐NA, and 4‐NA, respectively), 4‐methyl‐3‐nitroaniline (4‐M‐3‐NA), 2‐methyl‐4‐nitroaniline (2‐M‐4‐NA), and 4‐methyl‐3,5‐dinitroaniline (4‐M‐3,5‐DNA), are studied in toluene and 1,4‐dioxane. Steady‐state fluorescence data show the higher efficiency of the 4‐NAs as quenchers and fit with a sphere‐of‐action model. This suggests a 4‐NA tendency of being in close proximity to the fluorophore, which could be connected with their high polarity/hyperpolarizability. In addition, emission and excitation spectra evidence the formation of emissive pyrene—NA ground‐state complexes in…
Genotoxic effects of the herbicides alachlor, atrazine, pendimethaline, and simazine in mammalian cells
1994
Antiviral Properties of Chemical Inhibitors of Cellular Anti-Apoptotic Bcl-2 Proteins
2017
Viral diseases remain serious threats to public health because of the shortage of effective means of control. To combat the surge of viral diseases, new treatments are urgently needed. Here we show that small-molecules, which inhibit cellular anti-apoptotic Bcl-2 proteins (Bcl-2i), induced the premature death of cells infected with different RNA or DNA viruses, whereas, at the same concentrations, no toxicity was observed in mock-infected cells. Moreover, these compounds limited viral replication and spread. Surprisingly, Bcl-2i also induced the premature apoptosis of cells transfected with viral RNA or plasmid DNA but not of mock-transfected cells. These results suggest that Bcl-2i sensiti…
Effects of leflunomide (HWA 486) on expression of lymphocyte activation markers
1993
Leflunomide (HWA 486), an isoxazol derivative, has been shown to be very effective in combating autoimmune diseases and transplantation rejection in a great number of animal models. The main metabolite of leflunomide, A77 1726, is a potent antiproliferative compound. To further elucidate this effect, lymphocytes of healthy human donors were cultured for 24, 48 or 72 h in the presence of PHA or immobilized anti-CD3 antibody. A77 1726 was added at concentrations between 10 and 100 microM. Flow cytometric evaluation of early activation or proliferation markers (IL-2 and transferrin receptors, respectively) showed that their expression was inhibited in a dose-dependent manner by A77 1726. Toget…
Synthesis and characterization of new polyamino-cyclodextrin materials.
2011
With the aim of the synthesis of chemically modified cyclodextrins bearing polyamine pendant groups, potentially useful as capping agents for the preparation of nanosized metal systems or as auxiliaries for gene transfection, the reaction between the heptakis-(6-iodo)-(6-deoxy)-b-cyclodextrin and various polyamines has been explored. This synthetic approach allows obtaining materials constituted by mixtures of cyclodextrins, having different degrees of substitution, which were satisfactorily characterized by means of various complementary techniques (ESI-MS, NMR, potentiometric titration). The products obtained were successfully subjected to preliminary tests for their binding abilities tow…
N-[tert-Butoxycarbonylglycyl-(Z)-α,β-dehydrophenylalanylglycyl-(E)-α,β-dehydrophenylalanylphenylalanyl]-4-nitroaniline ethanol solvate
2005
The alpha,beta-dehydrophenylalanine residues influence the conformation of the title pentapeptide Boc0-Gly1-Delta(Z)Phe2-Gly3-Delta(E)Phe4-L-Phe5-p-NA ethanol solvate, C42H43N7O9.C2H5OH. The first unsaturated phenylalanyl (Delta(Z)Phe2) and the third glycyl (Gly3) residues form a type I beta turn, while the second unsaturated phenylalanyl (Delta(E)Phe4) and the last phenylalanyl (L-Phe5) residues are part of a type II beta turn. All the amino acids in the peptide are linked trans to one another. The crystal structure is stabilized by intra- and intermolecular hydrogen bonds.
Biopartitioning micellar chromatography: An alternative high-throughput method for assessing the ecotoxicity of anilines and phenols
2007
An investigation of the use of the chromatographic retention (log k) as an in vitro approach for modelling the toxicity to Fathead Minnows of anilines and phenols is developed. A data set of 65 compounds with available experimental toxicity data was used. Log k data at three pH values were used for the compounds classification and two groups or 'MODEs' were identified. For one 'MODE' a quantitative retention-activity relationship (QRAR) model was calculated. Finally, it was used to estimate the toxicity to Fathead minnows of anilines and phenols for which experimental data are not available. These estimations were compared to those obtained from another toxicity (to Tetrahymena pyriformis) …
Evaluation of the interaction and drug release from alpha,beta-polyaspartamide derivatives to a biomembrane model
2005
This article reports on a comparative study on the ability of various polymers, containing hydrophilic and/or hydrophobic groups, to interact with a biomembrane model using the differential scanning calorimetry (DSC) technique. Multilamellar vesicles of mixed dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidic acid (DMPA) were chosen as a model of cell membranes. The investigated samples were a water soluble polymer, the alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) and its derivatives partially functionalized with polyethylene glycol (PEG2000) to obtain PHEA-PEG2000, with hexadecylamine (C16) to obtain PHEA-C16, and with both compounds to obtain PHEA-PEG2000-C16. Th…