Search results for "Thiazoles"
showing 10 items of 114 documents
Synthesis and evaluation of 18F-fluoroethylated benzothiazole derivatives for in vivo imaging of amyloid plaques in Alzheimer's disease
2010
Amyloid aggregates play a major role in the development of Alzheimer's disease. Targeting these aggregates by PET probes enables non-invasively the detection and quantification of amyloid deposit distribution in human brains. Based on benzothiazole core structure a series of amyloid imaging agents were developed. Currently [(11)C]2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole (Pittsburgh Compound-B (PIB) is the most specific and widely used amyloid imaging ligand. But due to the short half life of (11)C, longer lived (18)F-labeled derivatives offer logistic advantages and higher contrast images. In this work, three different [(18)F]fluoroethoxy-substituted benzothiazole derivatives ([(18…
Thioflavin T Hydroxylation at Basic pH and Its Effect on Amyloid Fibril Detection
2008
The fluorescent dye thioflavin T (ThT) is commonly used for in situ amyloid fibril detection. In this work, we focused on the spectroscopic properties and chemical stability of ThT in aqueous solution as a function of pH, temperature, and dye concentration. A reversible hydroxylation process occurs in alkaline solutions, which was characterized using a combination of UV-vis absorption spectroscopy, proton NMR, and density functional theory (DFT). On the basis of these studies, we propose a chemical structure for the hydroxylated form. Finally, by means of fluorescence spectroscopy, ThT hydroxylation effects on in situ amyloid detection have been investigated, providing new insights on the e…
Secondary nucleation and accessible surface in insulin amyloid fibril formation.
2008
At low pH insulin is highly prone to self-assembly into amyloid fibrils. The process has been proposed to be affected by the existence of secondary nucleation pathways, in which already formed fibrils are able to catalyze the formation of new fibrils. In this work, we studied the fibrillation process of human insulin in a wide range of protein concentrations. Thioflavin T fluorescence was used for its ability to selectively detect amyloid fibrils, by mechanisms that involve the interaction between the dye and the accessible surface of the fibrils. Our results show that the rate of fibrillation and the Thioflavin T fluorescence intensity saturate at high protein concentration and that, surpr…
Interaction of metal ions with D-glucobenzothiazoline: isolation and characterization of the resultant products
2002
Six different metal-ion complexes of D-glucobenzothiazoline were synthesized and characterized by analytical and spectral techniques. Formation of different types of species (ML and ML2) were observed with Cu2+, Ag+, Cd2+, Hg2+, and Zn2+ ions. Existence of an anomeric mixture in the case of the Cu2+ complex is identified from the EPR spectra, and the results were further supported by the simulated spectra. The structures were proposed based on different studies.
Synthesis and anti-HIV activity of 2,3-diaryl-1,3-thiazolidin-4-ones
2002
Several 1,3-thiazolidin-4-ones bearing a 2,6-dihalophenyl group at C-2 and a variously substituted phenyl ring at N-3 have been synthesized and tested as anti-HIV agents. The results of the in vitro tests showed that some of them proved to be effective inhibitors of HIV-1 replication.
Synthesis of new 2,3-diaryl-1,3-thiazolidin-4-ones as anti-HIV agents
2004
Several 2,3-diaryl-1,3-thiazolidin-4-ones were synthesized and evaluated as anti-HIV agents. The results of the in vitro tests showed that some of them were highly effective inhibitors of HIV-1 replication at 30-50 nM concentrations with minimal cytotoxicity, thereby acting as non-nucleoside HIV-1 reverse transcriptase inhibitors (NNRTIs).
Alternariol-induced cytotoxicity in Caco-2 cells. Protective effect of the phenolic fraction from virgin olive oil.
2014
The extra virgin olive oil (EVOO) has been associated to antioxidant effects. The mycotoxin alternariol (AOH) can contaminate olives. The aims of this work were to determine the cytotoxic effects and reactive oxygen species (ROS) produced by AOH, tyrosol and oleuropein (two polyphenols of olive oil) and a real EVOO extract in Caco-2 cells. The MTT assay and the ROS production by the H2-DCFDA probe were used. Results demonstrated that AOH reduces cellular proliferation depending on concentration, whereas tyrosol and oleuropein did not (12.5-100 μM). The combination of AOH + oleuropein (50 μM) increased cell proliferation (24%) whereas, AOH + tyrosol decreased (47%) it. Besides, AOH increased…
Synthesis and Biological Properties of Benzothiazole, Benzoxazole, and Chromen-4-one Analogues of the Potent Antitumor Agent 2-(3,4-Dimethoxyphenyl)-…
2008
New fluorinated 2-aryl-benzothiazoles, -benzoxazoles, and -chromen-4-ones have been synthesized and their activity against MCF-7 and MDA 468 breast cancer cell lines compared with the potent antitumor benzothiazole 5. Analogues such as 9a, b and 12a, d yielded submicromolar GI50 values in both cell lines; however, none of the new compounds approached 5 in terms of antitumor potency. For 5, binding to the aryl hydrocarbon receptor appeared to be necessary but not sufficient for growth inhibition.
Trehalose effects on α-crystallin aggregates
2007
alpha-Crystallin in its native state is a large, heterogeneous, low-molecular weight (LMW) aggregate that under certain conditions may progressively became part of insoluble high-molecular weight (HMW) systems. These systems are supposed to play a relevant role in eye lens opacification and vision impairment. In this paper, we report the effects of trehalose on alpha-crystallin aggregates. The role of trehalose in alpha-crystallin stress tolerance, chaperone activity and thermal stability is studied. The results show that trehalose stabilizes the alpha-crystallin native structure, inhibits alpha-crystallin aggregation, and disaggregates preformed LMW systems not affecting its chaperone acti…
Chronic peroxisome proliferator-activated receptorβ/δ agonist GW0742 prevents hypertension, vascular inflammatory and oxidative status, and endotheli…
2015
Endothelial dysfunction plays a key role in obesity-induced risk of cardiovascular disease. The aim of the present study was to analyze the effect of chronic peroxisome proliferator-activated receptor (PPAR)β/δ agonist GW0742 treatment on endothelial function in obese mice fed a high-fat diet (HFD).Five-week-old male mice were allocated to one of the following groups: control, control-treated (GW0742, 3 mg/kg per day, by oral gavage), HFD, HFD + GW0742, HFD + GSK0660 (1 mg/kg/day, intraperitoneal) or HFD-GW0742-GSK0660 and followed for 11 or 13 weeks. GW0742 administration to mice fed HFD prevented the gain of body weight, heart and kidney hypertrophy, and fat accumulation. The increase in …