A5025482032- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- melanin and skin pigmentation
- Metalloenzymes and iron-sulfur proteins
- Biochemical Analysis and Sensing Techniques
- Erythrocyte Function and Pathophysiology
- Electrocatalysts for Energy Conversion
- Metal complexes synthesis and properties
- Phytochemicals and Antioxidant Activities
- Pancreatic function and diabetes
- Carbohydrate Chemistry and Synthesis
- Enzyme Structure and Function
- Diet, Metabolism, and Disease
- Biochemical and Molecular Research
- Crystallography and molecular interactions
- Advanced battery technologies research
- Metal-Catalyzed Oxygenation Mechanisms
- Synthesis of Organic Compounds
- Metabolism, Diabetes, and Cancer
- Fluorine in Organic Chemistry
- Chemical Synthesis and Analysis
- Microbial Metabolites in Food Biotechnology
- Advanced Photocatalysis Techniques
- Enzyme function and inhibition
- Nanocluster Synthesis and Applications
Centre National de la Recherche Scientifique
2014-2025
Centrale Marseille
2014-2025
Aix-Marseille Université
2011-2023
Institut des Sciences Moléculaires de Marseille
2006-2023
University of California, Berkeley
2006
Université Paris Cité
1999-2006
Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques
2006
Massey University
2003-2005
Université Paris-Saclay
2005
Université Paris-Sud
1999-2004
A human-bacterium symbiosis leads to the production of an antipathogenic and safe RiPP with a novel thioether network.
The synthesis and characterization of a dinuclear bis(thiosemicarbazone) cobalt complex [Co2 L2 (NCS)2 ] is reported. This exhibits significant catalytic activity for hydrogen production in DMF by using triethylammonium (Et3 NHBF4 ) as the proton source. Cyclic voltammetry data allowed maximum turnover frequency 130 s-1 1 m concentration to be determined. nature process dihydrogen were confirmed gas analysis during controlled potential electrolysis experiments. Quantum chemical calculations...
With the aim to develop effective and selective human tyrosinase inhibitors, we investigated aurone derivatives whose B-ring was replaced by a non-oxidizable 2-hydroxypyridine-N-oxide (HOPNO) moiety. These aurones were synthesized evaluated as inhibitors of purified tyrosinase. Excellent inhibition activity revealed rationalized theoretical calculations. The backbone especially found play crucial role, HOPNO moiety alone provided very modest on Furthermore, in vitro confirmed measuring...
In the pursuit of developping efficient and green methods for hydrogen production, a key focus is development most energy-efficient catalysts. The analysis various proton sources primarily aims at eliminating rate-limiting steps associated with protonation events ensuring stability catalyst. this work, we report how two distinct can cause mechanistic shift in evolution reaction. Specifically, explore reactivity change presence triethylammonium trifluoroacetic acid thiosemicarbazone-based...
Phosphoglucose isomerase (PGI; E.C. 5.3.1.9) catalyzes the second step in glycolysis, interconversion of D-glucose-6-phosphate and D-fructose-6-phosphate. We determined X-ray crystal structure rabbit PGI complexed with a competitive inhibitor activity, 5-phospho-D-arabinonate (5PAA), at 1.9 A resolution. 5PAA is better mimic proposed cis-enediol(ate) intermediate than 6-phospho-D-gluconate, which was used previously reported PGI. The orientation bound enzyme active site predicts that residue...
Tyrosinase (Ty) is a copper-containing enzyme widely present in plants, bacteria, and humans, where it involved biosynthesis of melanin-type pigments. Development Ty inhibitors an important approach to control the production accumulation pigments living systems. In this paper, we focused our interest phenylthiourea (PTU) phenylmethylene thiosemicarbazone (PTSC) recognized as tyrosinase by combining enzymatic studies coordination chemistry methods. Both are efficient mushroom they can be...
This work reports on the synthesis and characterization of a series mononuclear thiosemicarbazone nickel complexes that display significant catalytic activity for hydrogen production in DMF using trifluoroacetic acid as proton source. The ligand framework was chemically modified by varying electron-donating abilities para substituents phenyl rings, which expected to impact capability resulting reduce protons into hydrogen. Over four were obtained, one with thiomethyl substituent, NiSCH3,...
Abstract The search for alternative non‐noble transition metal catalysts able to evolve hydrogen has been the focus of intense research. Molecular complexes bearing redox‐active ligands have reported as efficient electrocatalysts evolution reaction (HER). This study showcases a new family nickel‐thiosemicarbazone displaying significant activity HER in DMF solvent using trifluoracetic acid proton source. Following previous works our group, ligand was stereochemically tailored, placing methoxy...
NMR was used to study the thermodynamics of cis → trans isomerization for prolyl amide bonds in compounds shown. The magnitude Kt/c C-terminal esters is greater than corresponding amides, signifying stronger backbone stereoelectronic effects esters. Increasing steric bulk N-terminal residue from Ac- Ac-Gly- favors conformation. Incorporation a Phe Pro, however, shifts equilibrium favor conformation, via stabilizing aromatic−proline interaction.
A series of eight dipeptides the general formula Ac-Phe-Pro*-NHMe was synthesized and thermodynamics cis → trans isomerization about central amide bond were studied by NMR. Pro* represents following prolines: l-proline (Pro), l-trans-4-hydroxyproline (Hyp), l-cis-4-hydroxyproline (hyp), l-cis-4-methoxyproline (hyp[OMe]), l-trans-3-hydroxyproline (3-Hyp), l-cis-3-hydroxyproline (3-hyp), l-2,3-trans-3,4-cis-3,4-dihydroxyproline (DHP), l-2,3-cis-3,4-trans-3,4-dihydroxyproline (dhp). The...
Abstract Elucidation of the binding modes Ty inhibitors is an important step for in‐depth studies on how to regulate tyrosinase activity. In this paper we highlight extraordinarily versatile effects aurone structure mushroom Depending position OH group B‐ring, aurones can behave either as substrates or hyperbolic activators. The synthesis a hybrid through combination moiety with HOPNO (2‐hydroxypyridine N ‐oxide), good metal chelate, led us new, efficient, mixed inhibitor tyrosinase. Another...
Abstract Tyrosinase is a copper‐containing enzyme found in plants and bacteria, as well humans, where it involved the biosynthesis of melanin‐type pigments. inhibitors have attracted remarkable research interest whitening agents cosmetology, antibrowning food chemistry, therapeutics. In this context, commercially available tyrosinase from mushroom (TyM) frequently used for identification inhibitors. This bacterial (TyB) been subjects intense biochemical structural studies, including X‐ray...
We describe the synthesis and characterization of a new mononuclear palladium complex ( PdL ) based on thiosemicarbazone ligand. X‐ray diffraction data collected single crystals reveal that is neutral entity with symmetric square‐planar geometry around metal center. The exhibits an electrocatalytic behavior for proton reduction in DMF solvent using trifluoroacetic acid (TFA) as source. Gas analysis under controlled conditions during 4 h at pool mercury working electrode showed moderate...
Tyrosinases act in the development of organoleptic properties tea, raisins, etc., but also cause unwanted browning fruits, vegetables, and mushrooms. The tyrosinase from Agaricus bisporus has been used as a model to study inhibitors, which are indispensable treatment skin pigmentation disorders. However, this disadvantages such side enzyme activities presence multiple isoenzymes. Therefore, we aimed introduce new model. pro-tyrosinase Polyporus arcularius was overproduced Escherichia coli....
Phosphoglucose isomerase (EC 5.3.1.9 ) catalyzes the second step in glycolysis, reversible isomerization of d -glucose 6-phosphate to -fructose 6-phosphate. The reaction mechanism involves acid-base catalysis with proton transfer and proceeds through a cis -enediol(ate) intermediate. 5-Phospho- -arabinonohydroxamic acid (5PAH) is synthetic small molecule that resembles intermediate, differing only it has nitrogen atom place C1. Hence, 5PAH best inhibitor reported date K i 2 × 10 −7 M. Here...
The human oxytocinase/insulin‐regulated aminopeptidase (OTase/IRAP) is a 1024 amino acid type II integral membrane protein that expressed mainly in fat, muscle and placenta tissues. It has been thought to be involved the control of onset labour but recently rat OTase/IRAP was shown participate regulation glucose transporter isoform 4 vesicle trafficking adipocytes as well. To approach an understanding gene organization determined. Accordingly, three overlapping genomic clones were isolated...
2-Hydroxypyridine-N-oxide (HOPNO) is described as a new and efficient transition-state analog (TS-analog) inhibitor for the mushroom tyrosinase with an IC50 = 1.16 μM KI 1.8 μM. Using binuclear copper(II) complex [Cu2(BPMP)(μ−OH)](ClO4)2 (2) known functional model catecholase activity, we isolated fully characterized 1:1 (2)/OPNO adduct in which HOPNO deprotonated chelates only one Cu-atom of site bidentate mode. On basis these results, structural inhibition by proposed.
In the following work, we carried out a systematic study investigating behavior of thiosemicarbazone-nickel (II) complex (NiTSC-OMe) as molecular catalyst for photo-induced hydrogen production. A comprehensive comparison regarding combination three different chromophores with this has been performed, using [Ir(ppy)2(bpy)]PF6, [Ru(bpy)3]Cl2 and [ZnTMePy]PCl4 photosensitizers. Thorough evaluation parameters affecting evolution experiments (i.e. concentration, pH, solvent nature ratio),...
An efficient preparation of pure ethyl Z- and E-α,α-difluoro-4-phenyl-3-butenoate 1a 1b together with the corresponding acids 2a 2b is described. The procedures involve stereocontrolled additions •CF2CO2Et to phenylacetylene or β-bromostyrene. Compound easily obtained by addition via a mechanism where stereochemistry controlled an electron-transfer process produce predominantly Z vinyl anion. product addition−elimination E-β-bromostyrenes steric factors in conformational equilibration intermediates.
Abstract The deciphering of the binding mode tyrosinase (Ty) inhibitors is essential to understand how regulate activity. In this paper, by combining experimental and theoretical methods, we studied an unsymmetrical functional model its interaction with 2‐hydroxypyridine‐ N ‐oxide (HOPNO), a new efficient competitive inhibitor for bacterial Ty. was dinuclear copper complex bridged chelated ring two different complexing arms (namely (bis(2‐ethylpyridyl)amino)methyl...