Search results for "amide"

Ligand substitution reactions of the [ReX6]2− (X=Cl, Br) anions. Synthesis and crystal structure of novel oxalato complexes of rhenium(IV)

2006

Abstract The reaction of K2[ReX6] (X = Cl, Br) with oxalic acid and triethylamine in dimethylformamide solution yields the substituted complexes [ReX4(ox)]2− and cis-[ReX2(ox)2]2−, which can be obtained separately depending on the amount of added amine. The crystal structures of (PPh4)2[ReBr4(ox)], cis-(PPh4)2[ReBr2(ox)2] and cis-(AsPh4)2[ReCl2(ox)2] have been determined by single-crystal X-ray diffraction. The anionic complexes are octahedral with only slight distortions. The direct isolation of the pure complexes as well as the formation of only the cis isomers – without the presence of trans isomers and/or [Re(ox)3]2− – is probably due to the kinetic inertness of Re(IV)–X bonds, which in…

A novel and simple method for the purification of extracellular levansucrase from Zymomonas mobilis.

2003

A new and simple method for the purification of extracellular levansucrase from Zymomonas mobilis from highly viscous fermentation broth was developed. After incubation of the fermentation broth with a fructose-polymer cleaving enzyme preparation (Fructozyme, Novozymes, DK) for 48 h, levansucrase precipitated as aggregates and was redissolved in a 3 M urea solution. By ongoing size-exclusion chromatography on Sephacryl S-300 the final levansucrase preparation was purified 100-fold and exhibited a specific activity of 25-35 U/mg(protein). The levansucrase was stable in 3 M urea solution for at least four months without inactivation. To maximize the enzyme yield the dynamic changes of extrace…

Inhibition of B2 receptor internalization delays its dephosphorylation

1997

Studies on sea urchin oocytes. II. Synthesis of RNA during oogenesis.

1972

Abstract Isolated oocytes of the sea urchin Paracentrotus lividus actively incorporate 3H-uridine into RNA. Labeled RNA was analysed by sucrose gradient and acrylamide gel electrophoresis following cell fractionation. Much of the radioactivity is incorporated at the nucleolar level in the form of rRNA precursors. The kinetics of maturation of these latter suggests that this occurs at a slower rate than during embryogenesis. Other non-nucleolar RNA classes are also actively labelled and retained in the nucleus for many hours. These results are confirmed by an autoradiographic investigation.

Echovirus 1 Endocytosis into Caveosomes Requires Lipid Rafts, Dynamin II, and Signaling EventsV⃞

2004

Binding of echovirus 1 (EV1, a nonenveloped RNA virus) to the α2β1 integrin on the cell surface is followed by endocytic internalization of the virus together with the receptor. Here, video-enhanced live microscopy revealed the rapid uptake of fluorescently labeled EV1 into mobile, intracellular structures, positive for green fluorescent protein-tagged caveolin-1. Partial colocalization of EV1 with SV40 (SV40) and cholera toxin, known to traffic via caveosomes, demonstrated that the vesicles were caveosomes. The initiation of EV1 infection was dependent on dynamin II, cholesterol, and protein phosphorylation events. Brefeldin A, a drug that prevents SV40 transport, blocked the EV1 infection…

MICELLAR CHROMATOGRAPHIC PROCEDURE WITH DIRECT INJECTION FOR THE DETERMINATION OF SULFONAMIDES IN MILK AND HONEY SAMPLES

2001

The capability of liquid chromatography with micellar mobile phases of sodium dodecyl sulfate (SDS), of allowing the direct injection of biological fluids into reversed-phase columns, was applied to the determination of sulfonamides in milk and honey samples. The chromatographic behavior of a group of 15 sulfonamides was studied at pH 3.0 where the drugs showed a greater separation space. Acetonitrile was added to the mobile phase to decrease the retention of the most hydrophobic drugs and increase the efficiencies, which yielded a higher resolution. The samples were diluted with 0.10 M SDS to facilitate the solubilization of the matrix compounds and release the protein-bound drugs. The pro…

Updating chromatographic predictions by accounting ageing for single and tandem columns.

2018

The most efficient optimization methodologies in liquid chromatography are based on the modeling and prediction of the chromatographic behavior for each compound in the sample. However, when the column suffers some ageing after the modeling process, predictions may differ significantly from the actual separation. Repeating the modeling is especially troublesome when several columns are involved, as is the case of coupled columns. We propose a shortcut to correct the time and peak profiles in these situations, after evaluating the effects of ageing. The original models are corrected by introducing parameters accounting for column ageing, obtained using the data of a small subset of compounds…

1H NMR and UV-vis spectroscopic characterization of sulfonamide complexes of nickek(II)-carbonic anhydrase. Resonance assignments based on NOE effects

1992

The binding of acetazolamide, p-fluorobenzensulfonamide, p-toluenesulfonamide, and sulfanilamide to nickel(II)-substituted carbonic anhydrase II has been studied by 1H NMR and electronic absorption spectroscopies. These inhibitors bind to the metal ion forming 1:1 complexes and their affinity constants were determined. The 1H NMR spectra of the formed complexes show a number of isotropically shifted signals corresponding to the histidine ligands. The complexes with benzene-sulfonamides gave rise to very similar 1H NMR spectra. The NMR data suggest that these aromatic sulfonamides bind to the metal ion altering its coordination sphere. In addition, from the temperature dependence of 1H NMR s…

In Silico Design, Synthesis and Biological Evaluation of Anticancer Arylsulfonamide Endowed with Anti-Telomerase Activity

2022

Telomerase, a reverse transcriptase enzyme involved in DNA synthesis, has a tangible role in tumor progression. Several studies have evidenced telomerase as a promising target for developing cancer therapeutics. The main reason is due to the overexpression of telomerase in cancer cells (85–90%) compared with normal cells where it is almost unexpressed. In this paper, we used a structure-based approach to design potential inhibitors of the telomerase active site. The MYSHAPE (Molecular dYnamics SHared PharmacophorE) approach and docking were used to screen an in-house library of 126 arylsulfonamide derivatives. Promising compounds were synthesized using classical and green methods. Com…

Lipid-Altering Efficacy of Ezetimibe/Simvastatin 10/20 mg Compared to Rosuvastatin 10 mg in High-Risk Patients with and without Type 2 Diabetes Melli…

2010

AIMS: This post hoc analysis compared the effects of switching to ezetimibe/simvastatin 10/20 mg (EZE/SIMVA) or rosuvastatin 10 mg (ROSUVA) in uncontrolled high-risk hypercholesterolemic patients with/without type 2 diabetes mellitus (T2DM) despite statin monotherapy. METHODS: Patients (n = 618) at high risk for coronary vascular disease with elevated LDL-C ≥100 and ≤190 mg/dL despite use of statins were randomized 1:1 to double-blind EZE/SIMVA 10/20 mg or ROSUVA 10 mg for 6 weeks. Patients were classified as having T2DM based on ≥1 of the following: diagnosis of T2DM, antidiabetic medication, or FPG ≥126 mg/dL. This analysis evaluated percent changes from baseline in lipids among patients …