Search results for "thiols"
showing 10 items of 23 documents
2,4,5-Triaryl imidazole probes for the selective chromo-fluorogenic detection of Cu(II). Prospective use of the Cu(II) complexes for the optical reco…
2019
The sensing behaviour toward metal cations and biothiols of two 2,4,5-triarylimidazole probes (3a and 3b) is tested in acetonitrile and in acetonitrile-water. In acetonitrile the two probes present charge-transfer absorption bands in the 320-350 nm interval. Among all cations tested only Cu(11) is able to induce bathochromic shifts of the absorption band in the two probes, which is reflected in marked colour changes. Colour modulations are ascribed to the formation of 1:1 Cu(II)-probe complexes in which the cation interacts with the imidazole acceptor heterocycle. Besides, the two probes present intense emission bands (at 404 and 437 nm for 3a and 3b respectively) in acetonitrile that are q…
Characterization of NO-Induced Nitrosative Status in Human Placenta from Pregnant Women with Gestational Diabetes Mellitus
2017
Dysregulation of NO production is implicated in pregnancy-related diseases, including gestational diabetes mellitus (GDM). The role of NO and its placental targets in GDM pregnancies has yet to be determined. S-Nitrosylation is the NO-derived posttranslational protein modification that can modulate biological functions by forming NO-derived complexes with longer half-life, termed S-nitrosothiol (SNO). Our aim was to examine the presence of endogenous S-nitrosylated proteins in cysteine residues in relation to antioxidant defense, apoptosis, and cellular signal transduction in placental tissue from control (n=8) and GDM (n=8) pregnancies. S-Nitrosylation was measured using the biotin-switch …
Physiological Levels of Nitric Oxide Diminish Mitochondrial Superoxide. Potential Role of Mitochondrial Dinitrosyl Iron Complexes and Nitrosothiols.
2017
Mitochondria are the major source of superoxide radicals and superoxide overproduction contributes to cardiovascular diseases and metabolic disorders. Endothelial dysfunction and diminished nitric oxide levels are early steps in the development of these pathological conditions. It is known that physiological production of nitric oxide reduces oxidative stress and inflammation, however, the precise mechanism of “antioxidant” effect of nitric oxide is not clear. In this work we tested the hypothesis that physiological levels of nitric oxide diminish mitochondrial superoxide production without inhibition of mitochondrial respiration. In order to test this hypothesis we analyzed effect of low p…
Insights into the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE
2017
17 p.-8 fig.
Design of new sensitive α,β-unsaturated carbonyl 1,8-naphtalimide fluorescent probes for thiol bioimaging
2017
International audience; We report herein an efficient synthesis of news naphtalimide-based fluorescent derivatives functionalized with an a,(3-unsaturated carbonyl group. Probes were synthesized from reaction of an amino-naphtalimide precursor with maleic anhydride. Photophysical study of fluorescent probes and cells labelling were performed, and showed that the reactive derivatives exhibit rich turn on fluorescence properties in presence of different biological thiol (Glutathione and Cysteine) making these systems a very promising way for thiol bioimaging.
Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry
2020
International audience; The knowledge about the molecular fraction contributing to white wines oxidative stability is still poorly understood. However, the role of S- and N-containing compounds, like glutathione and other peptides, as a source of reductant in many oxidation reactions, and acting against heavy metals toxicity, or lipid and polyphenol oxidation as ROS-scavenger is today very well established. In that respect, the aim of the present study is to introduce an original analytical tool for the direct determination of the available nucleophilic compounds in white wine under acidic pH conditions. One step derivatization of nucleophiles has been realized directly in wines using 4-met…
Biothiols, taurine, and lipid-soluble antioxidants in the edible pulp of Sicilian cactus pear (Opuntia ficus-indica) fruits and changes of bioactive …
2005
Biothiols, taurine, and flavonols, as well as tocopherols and carotenoids have been assessed in the edible pulp of Sicilian red (Sanguigna), yellow (Surfarina), and white (Muscaredda) cultivars of cactus pear. The yellow cultivar has the highest level of reduced glutathione (GSH, 8.1 +/- 0.78 mg/100 g pulp), whereas the white cultivar showed the highest amount of cysteine (1.21 +/- 0.12 mg/100 g pulp). Taurine accounted for 11.7 +/- 1.0 mg/100 g in the yellow pulp, while lower levels were measured in the others. With the exception of kaempferol in the yellow cultivar (2.7 +/- 0.2 microg/100 g pulp), the edible pulp of cactus pear was not a source of flavonols. Very low amounts of lipid-solu…
Impact of Hydrogen Peroxide on Protein Synthesis in Yeast.
2021
This article belongs to the Special Issue Thiol-Based Redox Regulation of Cellular and Organismal Function.
Exploring the Reactivity and Biological Effects of Heteroleptic N-Heterocyclic Carbene Gold(I)- Alkynyl Complexes
2020
With the aim to explore the effects of different organometallic ligands on the reactivity and biological properties of a series of twelve heteroleptic AuI complexes, of general formula [Au(NHC)(alkynyl)] (NHC = benzimidazolylidene or 1,3-dihydroimidazolylidene) were synthesized and characterized by 1H and 13C NMR and elemental analysis, and in some cases also by X-ray diffraction. The compounds were all stable in H2O/DMSO as established by NMR spectroscopy, while they could react with model thiols (EtSH) in the presence of water to undergo ligand-substitution reactions. 1H NMR experiments showed that dissociation of the more labile alkynyl ligand was possible for all compounds, while in the…
Contribution à l'étude des « goûts de lumière » dans le vin de champagne *. 1. Aspects analytiques - Dosage des mercaptans et des thiols dans les vins
1977
<p style="text-align: justify;">Plusieurs accidents appelés « goûts de lumière » ou « goûts de réduit » ont été observés dans les vins de champagne au cours de ces dernières années. Dans ce travail, nous avons mis au point une méthode d'appréciation de ces goûts par dosage des groupements thiols ou mercaptans dans les vins. L'analyse comparative montre une bonne concordance entre la concentration en groupements thiols et l'appréciation gustative.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">For some years, accidents called « light tastes » or « reduced tastes » have been occured in Champagne wines; a method for thiols and mercaptans…