Outils chimiques pour l'étude et la compréhension du rôle du sulfure d'hydrogène en biologie

Après avoir été considéré pendant des années comme un polluant environnemental, il a récemment été mis en évidence que le sulfure d hydrogène est le troisième transmetteur gazeux, aux côtés des monoxydes d azote et de carbone. Dans ce travail de thèse, deux types d outils moléculairesont été visés : a) Des sondes fluorescentes pour détecter H2S, basées sur une utilisation originale de la chimie de coordination cherchant à favoriser l attaque du sulfure d hydrogène sur le ligand plutôt que sur le métal. Malgré leur forte réponse à H2S en solution tampon, celles-ci ne se sont malheureusement pas révélées sélectives vis-à-vis d autres thiols biologiques. b) Des donneurs lents de sulfure d hydrogène. Les premiers composés développés, basée sur la chimie de coordination, se comportent malheureusement comme des donneurs rapides. Par contre, la seconde famille, constituée de molécules organiques, s est révélée être un excellent substitut des sels d H2S couramment utilisés dans les études biologiques malgré leurs effets indésirables. De plus, nous avons aussi répondu à un défi synthétique en obtenant le premier complexe Fe SH comportant un ligand hydrosulfure impliqué dans une liaison hydrogène, telle que celle trouvée dans les hémoglobines des bactéries Bacillus subtilis et Thermobifida fusca.Pas de résumé en anglaisPARIS5-Bibliotheque electronique (751069902) / SudocPARIS-BIUM-Bib. électronique (751069903) / SudocSudocFranceF

Supplementary material for the article: Wedmann, R.; Onderka, C.; Wei, S.; Szijártó, I. A.; Miljkovic, J. L.; Mitrovic, A.; Lange, M.; Savitsky, S.; Yadav, P. K.; Torregrossa, R.; et al. Improved Tag-Switch Method Reveals That Thioredoxin Acts as Depersulfidase and Controls the Intracellular Levels of Protein Persulfidation. Chemical Science 2016, 7 (5), 3414–3426. https://doi.org/10.1039/c5sc04818d

Supplementary material for: [https://doi.org/10.1039/c5sc04818d]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1925

Solution and Solid-State Characterization of Zn(II) Complexes Containing A New Tridentate N\u3csub\u3e2\u3c/sub\u3es Ligand

A new N2S ligand bis(pyridyl)(2-mercapto-1-methylimidazolyl)methane (2, Py2MeImS) has been synthesized and characterized. Treatment of this ligand with bromide and triflate salts of Zn(II) results in the complexes (Py2MeImS)ZnBr2 (3) and [(Py2MeImS)2Zn](OTf)2 (4), respectively. The solid-state structure of (Py2MeImS)ZnBr2 shows bidentate N,N-coordination of Py2MeImS to the zinc ion, with the sulfur atom of the 2-mercaptoimidazole moiety uncoordinated. Two conformers of 3 rapidly interconvert in solution at room temperature, and variable temperature NMR studies and DFT calculations were used to help assign the likely identity of these conformers. In contrast, the crystal structure of [(Py2MeImS)2Zn] (OTf)2 exhibits a zinc ion with a distorted octahedral geometry where the two sulfur atoms of the two ligands are coordinated to the zinc center in a cis-configuration. Even though the cis-isomer (4-cis) is calculated to be lower in energy than the trans-isomer (4-trans), the low temperature 1H NMR spectrum of 4 reveals a single symmetric species that is inconsistent with the cis-isomer observed in the solid-state structure. DFT calculations propose alternative higher energy structures, including a trans-configuration of the coordinated S-atoms of the two Py2MeImS ligands, as well as structures in which the 2-mercaptoimidazole groups are no longer coordinated to the zinc(II) center. These studies provide valuable insight into the potential binding modes of this new ligand and its behavior in solution

Efficient C3-alkylsulfenylation of indoles under mild conditions using Lewis acid-activated 8-quinolinethiosulfonates.

The importance of sulfur-containing compounds in various fields, ranging from material science1-2 to medicinal chemistry, 3 has called for the development of synthetic strategies to form carbon-sulfur (C-S) bonds. Thus, numerous approaches based on the nucleophilicity of thiols have been designed over the years, which mostly use air-sensitive noble metal catalysts.4- 9 At the opposite, the use of electrophilic sulfur reagents is also a powerful, more eco-friendly approach, in particular for the sulfenylation of C-H bonds into C-S bonds.10-11 In this context, the sulfenylation of indoles (Equation 1) has become a benchmark reaction to develop and test new sulfenyl transfer reagents, because indoles are good nucleophiles and their occurrence in many natural products or biological active compounds makes them attractive synthetic targets.12-14 For instance, metal-catalyzed or metal-free protocols have been proposed, in which disulfides, sulfinic acid and their salts, sulfonyl chlorides, sulfonylhydrazine, or Nthiophtalimides are used as source of electrophilic sulfur.10,15-16 Thiosulfonates (RSO2SR’) are another class of emerging17 reagents, which were also studied for C-S bond formation18-20 and for indole sulfenylation.21 However, despite the large pool of sulfenylation agents listed above, the difficult activation of the chalcogen centre essentially limits these reagents to the formation of C-S(aryl) bonds. On the other hand, the transfer of alkylsulfenyl groups requires harsher activating conditions and is so far still limited<br /

Reversible Detection and Quantification of Hydrogen Sulfide by Fluorescence Using the Hemoglobin I from Lucina pectinata

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Stereoselective synthesis of multifunctionalized 1,2,4-triazolidines by a ruthenium porphyrin-catalyzed three-component coupling reaction

Multifunctionalized 1,2,4-triazolidines have been synthesized by a ruthenium porphyrincatalyzed three-component coupling reaction. In a one-pot reaction, ruthenium porphyrins catalyzed the in situ generation of azomethine ylides from α-diazo esters and imines. Stereoselective 1,3-dipolar cycloaddition reactions of the azomethine ylides with dialkyl azodicarboxylates gave the corresponding 1,2,4-triazolidines in good yields (up to 85%). Using chiral 8-phenylmenthanol α-diazo ester as the carbenoid source, chiral 1,2,4-triazolidines have been obtained with good diastereoselectivity (up to 84% de). Some of the 1,2,4-triazolidines exhibited good cytotoxicity against human nasopharyngeal carcinoma (SUNE1) (IC50 = 10.4 μM) and human cervical carcinoma (Heia) (IC50 = 10.7 μM) cell lines. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.link_to_subscribed_fulltex

Synthesis, Stability, and Reactivity of [(TPA)Zn(SH)]+ in Aqueous and Organic Solutions

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