Neurocentre Magendie


Tél : 0540002526
Envoyer un email

PhD Sciences Biologiques et Médicales, co-tutelle Université Bordeaux 2 et Académie Nationale des Sciences d'Ukraine. Approche pharmacochimique de l’inhibition de l'angiogénèse tumorale (1998-2001)
Chercheur contractuel en chimie des substances naturelles à l’ENITA de Bordeaux (2001-2009)
Ingénieur de Recherche en chimie des micronutriments à l’ENITA de Bordeaux (2010)
HDR Sciences Chimiques (2012)

Expertise: organic synthesis, structural analysis, hapten, protein conjugate

(1) Synthèse et caractérisation de produits naturels : phyto-œstrogènes (isoflavones, flavanones, chalcones, flavans, lignanes), 3,4-dihydro-isocoumarines antibactériennes, arômes du vin (thiols volatils et S-conjugués à la cysteine, méthoxypyrazines). (2) Synthèse de leurs haptènes, préparation et caractérisation des immunogènes (couplage d’haptènes à des protéines) en vue du développement de tests ELISA. (3) Synthèse de métabolites. (4) HPLC en mode analytique et préparative, HPLC chirale, GC. (4) Analyse structurale associée : RMN, IR, MS... (5) Synthèse peptidique : en solution, en phase solide

18 publication(s) depuis Mars 2003:

Trier par

* equal contribution
Les IF indiqués ont été collectés par le Web of Sciences en

09/2017 | anal bioanal chem   IF 3.4
Derivatization-free LC-MS/MS method for estrogen quantification in mouse brain highlights a local metabolic regulation after oral versus subcutaneous administration.
Lozan E, Shinkaruk S, Al Abed SA, Lamothe V, Potier M, Marighetto A, Schmitter JM, Bennetau-Pelissero C, Bure C

17beta-Estradiol (17beta-E2) is a steroid with pleiotropic actions. In addition to being a sexual hormone, it is also produced in the brain where it modulates the reproductive axis. It has been shown that 17beta-E2 also acts on synaptic plasticity and plays a role in neurological pathways and in neurodegenerative diseases. Assaying this steroid in the brain is thus interesting to improve our knowledge of 17beta-E2 effects in the brain. However, 17beta-E2 concentration in the central nervous system has been reported to be of a few nanograms per gram wet weight (nanomolar range concentration); therefore, its quantification requires both an efficient extraction process and a sensitive detection method. Herein is presented a derivatization-free procedure based on solid-phase extraction followed by LC-MS/MS analysis, targeted on 17beta-E2, its isomer17alpha-E2, and its metabolites estrone (E1) and estriol (E3). This extraction process allowed reaching 96% 17beta-E2 recovery from the mouse brain. Limit of detection (LOD) and limit of quantification (LOQ) values of 0.5 and 2.5 pmol mL(-1), respectively, were reached for both 17alpha-E2 and 17beta-E2. LOD values for E1 and E3 were 0.01 and 0.025 pmol mL(-1), respectively. The variation coefficients for intra- and inter-assays were 6 and 14%, respectively, for both estradiol forms. The method was applied to assess estrogen levels in the mouse brain and hippocampus after 17beta-E2 acute (subcutaneous injection) and chronic (drinking water) physiological administration. Total estrogen levels were determined after enzymatic deconjugation and compared to free estrogen levels. While 17alpha-E2 was not detected in biological samples, 17beta-E2 and metabolite measurements highlight a local biotransformation of estrogens after physiological administration via drinking water. Graphical abstract Method workflow: After oral or subcutaneous Estradiol administration, mouse brain or hippocampus was removed. Samples were homogenized and prepared according to a liquid-liquid extraction, followed by a solid-phase extraction. Then, LC-MS/MS was optimized to quantify 17ss-E2, its isomer17alpha-E2, its metabolites estrone (E1) and estriol (E3) and their conjugates.

Two main precursors (S-3-(hexan-1-ol)-l-cysteine and S-3-(hexan-1-ol)-l-glutathione) of 3-sulfanylhexanol (3SH, formerly named 3-mercaptohexanol) have been identified so far in grape juice but a correlation between precursor concentrations in grape juices and 3SH concentrations in wines is not always observed. This suggests that there may be other compounds associated with the aromatic potential. In this work, S-3-(hexanal)-glutathione (Glut-3SH-Al) and its bisulfite (Glut-3SH-SO3) adduct were identified in Sauvignon blanc grape juice by liquid chromatography coupled to Fourier transform mass spectrometry experiments. A partial purification of the compounds was carried out by Medium Pressure Liquid Chromatography (MPLC) on the reverse phase using 5L of grape juice. The addition of synthetized Glut-3SH-Al and Glut-3SH-SO3 in the synthetic medium induced a significant release of 3SH after fermentation. Moreover, we demonstrate that Glut-3SH-Al and its bisulfite adduct are present in grape juice and could be considered as new direct 3SH precursors with molar conversion yields close to 0.4%.

03/02/2016 | J Agric Food Chem   IF 3.2
Identification and Organoleptic Contribution of Vanillylthiol in Wines.
Floch M, Shinkaruk S, Darriet P, Pons A

Vanillylthiol, a chemical compound reminiscent of clove and smoke, has been identified for the first time in young red and dry white wines. The chemical structure of this new aroma was confirmed by original chemical synthesis. Vanillylthiol was prepared by a two-step procedure from vanillin. The conversion of vanillin to divanillyl disulfide was easily achieved by treatment with an inorganic sulfur-donor reagent. Reduction of the disulfide gave the target thiol in good yield. The quantification of vanillylthiol in wine was performed by nonspecific liquid/liquid extraction (CH2Cl2), separation of the volatile compounds using gas chromatography, and specific detection using tandem mass spectrometry (triple quadrupole). Vanillylthiol was found particularly in young wines aged in new oak barrels. These wines contained between a few 50 ng/L to more than 8300 ng/L. The highest levels were found in red wines aged 12 months in new oak barrels. Given its perception threshold in a wine model solution (3.8 mug/L), vanillylthiol may contribute to the spicy, clove-like flavor of red wines aged in oak barrels.

02/2014 | Talanta   IF 4.2
Design and validation of a novel immunological test for enterolactone.
Shinkaruk S, Pinot E, Lamothe V, Schmitter JM, Baguenard L, Bennetau B, Bennetau-Pelissero C

Enterolactone (ENL) is produced by the gut microflora from lignans found in edible plants. ENL is estrogenic with no effect on the E-screen test and is a natural Selected Estrogen Receptor Modulator (SERM) with health interests that have to be checked in clinical studies with bioavailability assessment. Two haptens of ENL were synthesized, with a spacer arm at the C5 position having either 2 or 4 carbon atoms (ENLDelta2 and ENLDelta4, respectively). Hapten coupling to bovine serum albumin (BSA) was characterized by MALDI mass spectrometry. Polyclonal antibodies were obtained against the BSA conjugates. Additional conjugates were generated by coupling to swine thyroglobulin (Thyr). Homologous and heterologous competitive ELISAs were developed with Thyr or BSA conjugates as coating. The best assays were validated on biological samples from mice. Both antibodies exhibited the same IC50 at 1.5 ng mL(-1) with a detection limit below 0.5 ng mL(-1). Most cross-reactions with structurally related lignans were lower than 0.03%. This new assay type is faster, more specific and more reliable than existing ones.

01/12/2012 | Food Chem   IF 4.5
Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian men.
Shinkaruk S, Durand M, Lamothe V, Carpaye A, Martinet A, Chantre P, Vergne S, Nogues X, Moore N, Bennetau-Pelissero C

Glycitein is a Selective Estradiol Receptor Modulator (SERM) from soy. The study reports plasma bioavailability and urine excretion of glycitein compared to other soy isoflavones after a unique intake of food supplement based on soy germ containing 55.24mg isoflavones. Eighteen plasma and urinary sampling profiles collected over 48h from healthy young Caucasian men were analysed using specific ELISAs. Eight profiles contained equol. Glycitein T(max), C(max), AUC(0-->24h) and T((1/2)) in plasma were calculated. Urine T(max), % of excretion at 24h and clearance were assessed. Glycitein is one of the best absorbed flavonoids. Plasma steady-state level can be achieved by several intakes a day. Glycitein bioavailability is similar to that of daidzein and its urinary excretion is significantly higher than that of genistein. Equol does not affect glycitein bioavailability. Knowing glycitein bioavailability in man is essential for the development of soy-germ-based food supplements for health applications.

12/2011 | Neuropsychopharmacology   IF 6.4
Membrane mineralocorticoid but not glucocorticoid receptors of the dorsal hippocampus mediate the rapid effects of corticosterone on memory retrieval.
Dorey R, Pierard C, Shinkaruk S, Tronche C, Chauveau F, Baudonnat M, Beracochea D

This study was aimed at determining the type of the glucocorticoid membrane receptors (mineralocorticoid receptors (MRs) or glucocorticoid receptors (GRs)) in the dorsal hippocampus (dHPC) involved in the rapid effects of corticosterone or stress on memory retrieval. For that purpose, we synthesized corticosterone-3-O-carboxymethyloxime-bovine serum albumin conjugate (Cort-3CMO-BSA) conjugate (a high MW complex that cannot cross the cell membrane) totally devoid of free corticosterone, stable in physiological conditions. In a first experiment, we evidenced that an acute stress (electric footshocks) induced both a dHPC corticosterone rise measured by microdialysis and memory retrieval impairment on delayed alternation task. Both the endocrinal and cognitive effects of stress were blocked by metyrapone (a corticosterone synthesis inhibitor). In a second experiment, we showed that bilateral injections of either corticosterone or Cort-3CMO-BSA in dHPC 15 min before memory testing produced impairments similar to those resulting from acute stress. Furthermore, we showed that anisomycin (a protein synthesis inhibitor) failed to block the deleterious effect of Cort-3CMO-BSA on memory. In a third experiment, we evidenced that intra-hippocampal injection of RU-28318 (MR antagonist) but not of RU-38486 (GR antagonist) totally blocked the Cort-3CMO-BSA-induced memory retrieval deficit. In a fourth experiment, we demonstrated that RU-28318 administered 15 min before stress blocked the stress-induced memory impairments when behavioral testing occurred 15 min but not 60 min after stress. Overall, this study provides strong in vivo evidence that the dHPC membrane GRs, mediating the rapid and non-genomic effects of acute stress on memory retrieval, are of MR but not GR type.

Competitive inhibition serological assay for detection of the phytoestrogen glycitein (Glyc) was developed using surface plasmon resonance (SPR) technique with protein conjugates and polyclonal antibodies initially designed for the enzyme-linked immunosorbent assays (ELISA). The efficiency of the approach to the quantification of the soy isoflavone glycitein in water was investigated using the competitive reaction of analyte (free Glyc)and immobilized Glyc-BSA-conjugate with polyclonal antibodies. It was shown that the efficiency to detect Glyc drastically depends on the pH level of the probe solution. With the decrease in pH from 7.4 to 4.0, (i) the affinity of the specific reaction increases and (ii) the level of unspecific sorption becomes saturated. Non-specific adsorption to a SPR sensor surface obscures the specific component and shaded specific response at higher pH (6.0-7.4) when used serum for the quantification of specific analytes. The standard curves obtained in acidic solutions (pH 4-5) indicate that the linear part of the dependence completely covers the range between detection limit (0.1 mug/ml) and Glyc solubility in water (0.9 mug/ml). The difference in SPR- and ELISA-based analytical protocols as well as the requirements for increasing the efficiency in quantitative SPR analysis using purified antibodies is discussed.

13/04/2011 | J Agric Food Chem   IF 3.2
Identification of impact odorants contributing to fresh mushroom off-flavor in wines: incidence of their reactivity with nitrogen compounds on the decrease of the olfactory defect.
Pons M, Dauphin B, La Guerche S, Pons A, Lavigne-Cruege V, Shinkaruk S, Bunner D, Richard T, Monti JP, Darriet P

Analysis of wines from different grape varieties marked by sometimes intense aromatic nuances of fresh mushroom was performed by gas chromatography coupled with olfactometry. This analysis has led to the identification of several odoriferous zones, which were recalling a fresh mushroom odor. Two trace compounds responsible for these odoriferous zones, 1-nonen-3-one and 1-octen-3-one, have been identified and their content has been determined by using either a multidimensional gas chromatography technique coupled to olfactometry and mass spectrometry detection (in the case of 1-nonen-3-one) or the preparation of the derivative with O-2,3,4,5,6-pentafluorobenzylhydroxylamine hydrochloride in the presence of the deuterated form, as the internal standard (in the case of 1-octen-3-one), then gas chromatography coupled to mass spectrometry detection. The assays allowed the quantification of these compounds at concentration levels sometimes well above their detection and recognition olfactory threshold. We show that adding nitrogen compounds to the altered wines, such as an amino acid (glycine) or a tripeptide (glutathione), led to lower concentrations of 1-octen-3-one in wines and diminished smell of fresh mushrooms. The study of the reaction in a model medium, whose composition is close to wine, by liquid chromatography coupled to mass spectrometry demonstrated the formation of adducts between 1-octen-3-one and glycine, and 1-octen-3-one and glutathione characterized by NMR.

13/10/2010 | J Agric Food Chem   IF 3.2
Elucidation of the 1,3-sulfanylalcohol oxidation mechanism: an unusual identification of the disulfide of 3-sulfanylhexanol in sauternes botrytized wines.
Sarrazin E, Shinkaruk S, Pons M, Thibon C, Bennetau B, Darriet P

A four-step purification method was developed to isolate a citrus odorant detected by gas chromatography-olfactometry (GC-O), which was apparently specific to Sauternes botrytized wines. A fragmentation pattern of the odorant was obtained by multidimensional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O). The exact mass measurement was used to determine its elemental formula as C(6)H(12)OS. On the basis of these data, the unusual structure of 3-propyl-1,2-oxathiolane was synthesized and characterized for the first time. This confirmed its identification. Its occurrence in Sauternes wine extracts was demonstrated to result from the thermal oxidative degradation of 3-sulfanylhexanol disulfide (3,3'-disulfanediyldihexan-1-ol) in the GC injector. This disulfide was synthesized and then firmly identified for the first time in Sauternes wine. Although the presence of 3-sulfanylhexanol oxidation products had previously been reported in natural extracts (but not wine), the full oxidation pathway from 3-sulfanylhexanol to 3-propyl-gamma-sultine via 3,3'-disulfanediyldihexan-1-ol was clearly established for the first time. Because the disulfide has mainly been detected in Sauternes botrytized wines, this finding suggested a singular reactivity of 3-sulfanylhexanol in botrytized wines, thus opening up a wide range of new opportunities in wine chemistry.

Equol, one of the main metabolites of daidzein, is a chiral compound with pleiotropic effects on cellular signaling. This property may induce activation/inhibition of the estrogen receptors (ER) a or b, and therefore, explain the beneficial/deleterious effects of equol on estrogen-dependent diseases. With its asymmetric centre at position C-3, equol can exist in two enantiomeric forms (R- and S-equol). To elucidate the yet unclear mechanisms of ER activation/inhibition by equol, we performed a comprehensive analysis of ERa and ERb transactivation by racemic equol, as well as by enantiomerically pure forms. Racemic equol was prepared by catalytic hydrogenation from daidzein and separated into enantiomers by chiral HPLC. The configuration assignment was performed by optical rotatory power measurements. The ER-induced transactivation by R- and S-equol (0.1-10 microM) and 17b-estradiol (E2, 10 nM) was studied using transient transfections of ERalpha and ERbeta in CHO, HepG2 and HeLa cell lines. R- and S-equol induce ER transactivation in an opposite fashion according to the cellular context. R-equol and S-equol are more potent in inducing ERalpha in an AF-2 and AF-1 permissive cell line, respectively. Involvement of ERalpha transactivation functions (AF-1 and AF-2) in these effects has been examined. Both AF-1 and AF-2 are involved in racemic equol, R-equol and S-equol induced ERalpha transcriptional activity. These results could be of interest to find a specific ligand modulating ER transactivation and could contribute to explaining the diversity of equol actions in vivo.