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Vansteelandt M - Blanchet E - Egorov M - Petit F - Toupet L - Bondon A - Monteau F - Le Bizec B - Thomas O - Pouchus YF - Le Bot R - Grovel O
Ligerin, an antiproliferative chlorinated sesquiterpenoid from a marine-derived Penicillium strain
Journal of Natural Products
A new chlorinated sesquiterpenoid analogue of fumagillin, ligerin (1), was isolated from a marine-derived strain of Penicillium, belonging to the subgenus Penicillium, along with the known compounds penicillic acid (2), orcinol, and orsellinic acid. Chemical structures were established by an interpretation of spectroscopic data including IR, UV, and HRESIMS, together with analyses of 1D and 2D NMR spectra and X-ray analysis for the determination of the absolute configuration. Ligerin (1) displayed strong inhibitory activity against an osteosarcoma cell line. This is the first report of the isolation of a fumagillin analogue from a marine-derived Penicillium strain. © 2013 American Chemical Society and American Society of Pharmacognosy.

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Janssens G - Courtheyn D - Mangelinckx S - Prevost S - Bichon E - Monteau F - De Poorter G - De Kimpe N - Le Bizec B
Use of Isotope Ratio Mass Spectrometry to detect abuse of natural hormones in cattle: a review
Analytica Chimica Acta
Although substantial technical advances have been achieved during the past decades to extend and facilitate the analysis of growth promoters in cattle, the detection of abuse of synthetic analogs of naturally occurring hormones has remained a challenging issue. When it became clear that the exogenous origin of steroid hormones could be traced based on the 13C/12C isotope ratio of the substances, GC/C/IRMS has been successfully implemented to this aim since the end of the past century. However, due to the costly character of the instrumental setup, the susceptibility of the equipment to errors and the complex and time consuming sample preparation, this method is up until now only applied by a limited number of laboratories. In this review, the general principles as well as the practical application of GC/C/IRMS to differentiate between endogenous steroids and exogenously synthesized homologous compounds in cattle will be discussed in detail, and will be placed next to other existing and to be developed methods based on isotope ratio mass spectrometry. Finally, the link will be made with the field of sports doping, where GC/C/IRMS has been established within the World Anti-Doping Agency (WADA) approved methods as the official technique to differentiate between exogenous and endogenous steroids over the past few years. © 2013 Elsevier B.V. All rights reserved.

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Barbarossa A - Masetti R - Gazzottia T - Zama D - Astolfi A - Veyrand B - Pession A - Pagliuca G
Perfluoroalkyl substances in human milk: A first survey in Italy
Environment International
Due to their widespread diffusion, perfluoroalkyl substances (PFASs) have been frequently found in the environment and in several animal species. It has been demonstrated that they can easily reach also humans, mainly through diet. Being lactation a major route of elimination of these contaminants, their occurrence in human milk is of particular interest, especially considering that it generally represents the unique food source for newborns. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the two most important compounds of this family, have been frequently found in human milk at variable concentrations, but still limited data are available. The present study, the first conducted in Italy capable to detect these pollutants at ultra-trace levels by UPLC-MS/MS, confirmed the role of lactation as a relevant source of exposure for breastfed children. The measured concentrations ranged between 15 and 288 ng/L for PFOS and between 24 and 241 ng/L for PFOA. Moreover, mean concentrations and frequencies of both analytes resulted higher in milk samples provided by primiparous women, suggesting that the risk of intake might be higher for first-borns. Finally, comparing these results with previous data, PFOS gradual decrease over time since year 2000 was confirmed. © 2012 Elsevier Ltd. All rights reserved.

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Lechat MM - Pouvreau JB - Peron T - Gauthier M - Montiel G - Veronesi C - Todoroki Y - Le Bizec B - Monteau F - Macherel D - Simier P - Thoiron S - Delavault P
PrCYP707A1, an ABA catabolic gene, is a key component of Phelipanche ramosa seed germination in response to the strigolactone analogue GR24
Journal of experimental botany
After a conditioning period, seed dormancy in obligate root parasitic plants is released by a chemical stimulus secreted by the roots of host plants. Using Phelipanche ramosa as the model, experiments conducted in this study showed that seeds require a conditioning period of at least 4 d to be receptive to the synthetic germination stimulant GR24. A cDNA-AFLP procedure on seeds revealed 58 transcript-derived fragments (TDFs) whose expression pattern changed upon GR24 treatment. Among the isolated TDFs, two up-regulated sequences corresponded to an abscisic acid (ABA) catabolic gene, PrCYP707A1, encoding an ABA 8'-hydroxylase. Using the rapid amplification of cDNA ends method, two full-length cDNAs, PrCYP707A1 and PrCYP707A2, were isolated from seeds. Both genes were always expressed at low levels during conditioning during which an initial decline in ABA levels was recorded. GR24 application after conditioning triggered a strong up-regulation of PrCYP707A1 during the first 18 h, followed by an 8-fold decrease in ABA levels detectable 3 d after treatment. In situ hybridization experiments on GR24-treated seeds revealed a specific PrCYP707A1 mRNA accumulation in the cells located between the embryo and the micropyle. Abz-E2B, a specific inhibitor of CYP707A enzymes, significantly impeded seed germination, proving to be a non-competitive antagonist of GR24 with reversible inhibitory activity. These results demonstrate that P. ramosa seed dormancy release relies on ABA catabolism mediated by the GR24-dependent activation of PrCYP707A1. In addition, in situ hybridization corroborates the putative location of cells receptive to the germination stimulants in seeds. © The Author [2012]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved.

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Veyrand B - Sirot V - Durand S - Pollono C - Marchand P - Dervilly-Pinel G - Tard A - Leblanc JC - Le Bizec B
Human dietary exposure to Polycyclic Aromatic Hydrocarbons: results of the second French Total Diet Study
Environment International
In the frame of the second French Total Diet Study (TDS), the 15+1 EU priority polycyclic aromatics hydrocarbons (PAHs) were analyzed in 725 foodstuffs habitually consumed by the French population, using gas chromatography coupled to tandem mass spectrometry, after pressurized liquid extraction and purification on PS-DVB stationary phase. The highest PAH concentrations recovered in foodstuffs corresponded to the following contributors: chrysene (25.7%), benzo[b]fluoranthene (15.0%) and benz[a]anthracene (9.0%) whereas the lowest concentrations were those of dibenz[a,h]anthracene, 5 methylchrysene and dibenzo[a,h]pyrene (below 2.0%). By food groups, the current highest levels of total PAH were detected in mollusks and crustaceans, followed by the different oil based products. To estimate French population's exposure, contamination data were combined with national individual food consumption data. Mean daily exposure to the sum of benzo[a]pyrene, benz[a]anthracene, chrysene and benzo[b]fluoranthene (PAH4) was estimated to be 1.48 ng/kg bw/day in adults and 2.26 ng/kg bw/day in children. The main contributors to PAH exposure for adults are fats, bread and dried bread products followed by crustaceans and mollusks. The margin of exposure (MOE) approach indicates that exposure to PAHs through food is not a major health problem for French consumers. © 2013 Elsevier Ltd. All rights reserved.

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Kaabia Z - Dervilly-Pinel G - Hanganu F - Cesbron N - Bichon E - Popot MA - Bonnaire Y - Le Bizec B
Ultra high performance liquid chromatography/tandem mass spectrometry based identification of steroid esters in serum and plasma: An efficient strategy to detect natural hormone abuse in breeding and racing animals.
Journal of Chromatography A
During last decades, the use of natural steroids in racing and food producing animals for doping purposes has been flourishing. The endogenous or exogenous origin of these naturally occurring steroids has since remained a challenge for the different anti-doping laboratories. The administration of these substances to animals is usually made through an intra-muscular pathway with the steroid under its ester form for a higher bioavailability and a longer lasting effect. Detecting these steroid esters would provide an unequivocal proof of an exogenous administration of the considered naturally occurring steroids. A quick analytical method able to detect at trace level (below 50 pg/mL) a large panel of more than 20 steroid esters in serum and plasma potentially used for doping purposes in bovine and equine has been developed. Following a pre-treatment step, the sample is submitted to a solid phase extraction (SPE) before analysis with UPLC–MS/MS. The analytical method’s efficiency has been probed through three different in vivo experiments involving testosterone propionate intra-muscular administration to three heifers, 17-estradiol benzoate intramuscular administration to a bull and a heifer and nandrolone laurate intra-muscular administration to a stallion. The results enabled detecting the injected testosterone propionate and 17-estradiol benzoate 2 and 17 days, respectively, post-administration in bovine and nandrolone laurate up to 14 days post-administration in equine. The corresponding elimination profiles in bovine serum and equine plasma have been established. The first bovine experiment exhibited a maximal testosterone propionate concentration of 400 pg/mL in one of the three heifer serum within 5 h post-administration. The second bovine experiment reported a maximal 17-estradiol benzoate concentration of 480 pg/mL in the same matrix recorded 9 days after its administration. The last equine experiment resulted in a maximal nandrolone laurate concentration of 440 pg/mL in horse plasma 24 h after administration. © 2013 Elsevier B.V. All rights reserved.

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Deceuninck Y - Bichon E - Dervilly-Pinel G - Antignac JP - Le Bizec B
Fast and multiresidue determination of 20 glucocorticoids in bovine milk using UHPLC-MS/MS.
Journal of Chromatography A
Glucocorticoids constitute a class of molecules widely used in animal husbandry. Some of these compounds are licensed for veterinary practices while their use for growth promoting purposes is prohibited within the European Union. In order to ensure the respect of the legislation and consumers safety, several methodologies have been proposed to monitor these substances in various products, including edible matrices for which a regulatory limit has been set up (MRL). An extended range of targeted analytes together with reduced time of analysis and cost are however still current challenges regularly revisited according to the continuous technological improvements. In this context, the aim of the present study was to develop and implement a new fast and multi-residue method based on UHPLC–MS/MS for the determination of twenty glucocorticoids in bovine milk, included the screening of the three regulated MRL compounds (dexamethasone, betamethasone and prednisolone). This validated method authorizes such multi-analyte measurement within a 10 min runtime while the signal specificity is ensured through the SRM acquisition mode. Decision limits and detection capabilities were calculated in the range of 0.001–0.363 µg.L-1, which allows a very efficient control at low trace level for a potential illegal use of these substances. The performances obtained in terms of application range, selectivity and sensitivity were found to be significantly improved in comparison to other reported approaches either for screening or confirmation purposes: regarding linearity, correlation coefficients were above 0.98 within the range of 0.01–5.0 µg.L-1, repeatability and reproducibility parameters ranged from 1 to 30% with the maximum relative standard deviation (RSD) observed for cortisone (30.1%). Stability of the stock solutions and minor changes in the standard operating procedure have been included for the determination of ruggedness of the method. Identification was systematically ensured according to 4 identification points, RSD of transitions ratio (T2/T1) ranged from 3.2% and 19.3% and the RSD of the retention time was lower than 0.25%. © 2013 Elsevier B.V. All rights reserved.

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Nordström Joensen U - Veyrand V - Antignac JP - Blomberg Jensen M - Holm Petersen J - Marchand P - Roy C - Andersson AM - Le Bizec B - Jorgensen N
PFOS (perfluorooctanesulfonate) in serum is negatively associated with testosterone levels in healthy men
Human Reproduction
Study question: Is exposure to perfluorinated compounds (PFCs) associated with testicular function (reproductive hormone levels and semen quality) in healthy men? Summary answer: PFOS levels were significantly negatively associated with serum testosterone (total and calculated free), but not with any other reproductive hormones or semen quality. What is known already: In animals, some PFCs have endocrine disrupting potential, but few studies have investigated PFCs in relation to human testicular function. Previously, we and others have observed a negative association between serum PFC levels and sperm morphology. The potential associations with reproductive hormones remain largely unresolved. Study design, size, duration: A cross-sectional study of 247 men was conducted during 2008–2009. participants/materials, setting, methods: Healthy men from the general population, median age of 19 years, gave serum and semen samples. Serum samples were analysed for total testosterone (T), estradiol (E), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin-B and 14 PFCs, including perfluorooctanesulfonate (PFOS). Semen samples were analysed according to the WHO criteria. Main results and the role of chance: PFOS levels were negatively associated with testosterone (T), calculated free testosterone (FT), free androgen index (FAI) and ratios of T/LH, FAI/LH and FT/LH. Other PFCs were found at lower levels than PFOS and did not exhibit the same associations. PFC levels were not significantly associated with semen quality. PFOS levels in these samples collected in 2008–2009 were lower than in our previous study of men participating in 2003. Limitations, reasons for caution: Results were robust to adjustment for relevant confounders; however, the possibility of chance associations due to multiple testing or effects of uncontrolled confounding cannot be ruled out. Wider implications of the findings: Our previous findings of decreased sperm morphology in the most highly PFC exposed men were not replicated, possibly due to a lack of highly exposed individuals; however, a recent independent study also did corroborate such an inverse association. The negative association between serum PFOS and testosterone indicates that testosterone production may be compromised in individuals with high PFOS exposure. © The Author 2012. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.

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Courant F - Martzolff A - Rabin G - Antignac JP - Le Bizec B - Giraudeau P - Tea I - Akoka S - Couzinet A - Cogne G - Grizeau D - Goncalvez O
How metabolomics can contribute to bio-processes: a proof of concept study for biomarkers discovery in the context of nitrogen-starved microalgae grown in photobioreactors.
Metabolomics has been emerging for several years as a global chemical phenotyping approach offering fascinating descriptive capabilities for addressing life complexity. It facilitates the understanding of the mechanisms of biological and biochemical processes in complex systems and promises new insights into specific research questions. The objective of this study was to use for the first time a metabolomic approach based on liquid chromatography high resolution mass spectrometry for characterizing an alteration of the testicular function, namely impaired semen quality. Metabolomic fingerprints were generated from serum samples collected from Danish young men presenting low, intermediate, or high sperm concentrations. Serum metabolic profiles were found to be significantly different among the three groups of volunteers. The developed methodology permitted to correlate the studied clinical parameter (i.e., sperm concentration) with the metabolite profiles generated. Peptides related to the Protein Complement C3f were identified as putative markers associated with this clinical parameter. The biological interpretation and further robustness linked to this observation remain to be further investigated, in particular to address the inter- and intraindividual variabilities. © 2013 American Chemical Society.

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Babut M - Mathieu A - Pradelle S - Marchand P - Le Bizec B - Perceval O
Nationwide PCB congener pattern analysis in freshwater fish samples in France.
Knowledge and Management of Aquatic Ecosystems
The 2006 european directive on polychlorodibenzodioxins and related compounds in foodstuffs prompted in France a nationwide monitoring study of freshwater fish contamination by these compounds. A database covering about 300 sites (2848 samples of 36 fish species) was obtained from this study. This database was used to explore congener pattern distributions, in order to identify typical sources and the impact of biotransformation on these sources. Fish ecological traits and fish size are the main factors explaining the overall PCB contamination in the two pre-identified categories of species (high or low propensity to accumulate hydrophobic compounds). Lipid content is also an influencing factor, but its relationship to other factors remains uncertain. Species show distinct congener patterns, related more to their physiology than to ecological traits. Spatial patterns were studied on selected sites having more than five individuals analysed – either chub (Squalius cephalus) or barbel (Barbus barbus), the most widespread species in the database –. We identified six patterns, which mainly differed in the respective proportions of congeners potentially biotransformed by fish. No connection to typical sources, e.g. technical mixtures, was identified. These patterns instead represent an ageing path of the initial mixtures; they could be used for setting remediation priorities. © ONEMA, 2013.

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