High-Resolution Mass Spectrometry as a Tool To Evaluate the Sample Preparation of Sludge

International audienc

A complementary LC-ESI-MS and MALDI-TOF approach for screening antibacterial proteomic signature of farmed European Sea bass mucus

International audienceAntibacterial protection in the mucus is provided by antimicrobial compounds and till now few numbers of AMP and proteins were identified. Herein, mass spectral profiling of fresh mucus from farmed sea bass (Dicentrarchus labrax) using Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometer (MALDI-TOF) and liquid chromatography mass spectrometry is investigated in order to survey the infective/healthy status of the mucus. We identify AMP peptides of 2891.7, 2919.45 and 2286.6 Da molecular weight respectively and characterize Chrysophsins in the mucus of Dicentrarchus labrax. These peptides display broad-spectrum bactericidal activity against Gram-negative (Minimum Inhibitory Concentrations namely MICs < 0.5 μM) and Gram-positive bacteria (MICs < 0.5 μM) including Escherichia coli and Bacillus subtilis. Furthermore, sensitivity to yeast Candida albicans is reported for the first time and shows interesting MICs of less than 2 μM. We also demonstrate that the fish pathogen Aeromonas salmonoicida is sensitive to Chrysophsins (MICs ranging between 5 and 14 μM). Our mucus molecular mass mapping developed approach allows for fast exploration of immune status. Our data provides evidence that Chrysophsins are secreted by immune cells and are released in mucus of non-challenged farmed European sea bass. These results suggest that Chrysophsins, secreted by gills of red sea bream, are an important widespread component of Teleostei defense against disease

Copolyesters of isosorbide, succinic acid, and isophthalic acid: Biodegradable, high T-g engineering plastics

International audienceIsosorbide, succinyl chloride and isophthaloyl chloride are polycondensed under various reaction conditions. The heating in bulk with or without catalysts as well in an aromatic solvent without catalyst, and polycondensation with the addition of pyridine only yield low molar mass copolyesters. However, heating in chlorobenzene with addition of SnCl2 or ZnCl2 produces satisfactory molar masses. The number average molecular weights (Mn) of most copolyesters fall into the range of 700015,000 Da with polydispersities (PD) in the range of 39. The MALDI-TOF mass spectra almost exclusively displayed peaks of cyclics indicating that the chain growth was mainly limited by cyclization and not by side reactions, stoichiometric imbalance or incomplete conversion. The glass-transition temperatures increased with the content of isophthalic acid from 75 to 180 degrees C and the thermo-stabilities also followed this trend

Synthèse de polymères issus de l'amidon de maïs : étude des structures par combinaison des techniques MALDI-ToF et RMN

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Non-targeted investigation of benthic invertebrates ( Chironomus riparius ) exposed to wastewater treatment plant effluents using nanoliquid chromatography coupled to high-resolution mass spectrometry

International audienceNanoliquid chromatography (nanoLC) was coupled to high-resolution mass spectrometry (HRMS) to perform a non-targeted investigation on benthic invertebrates, Chironomus riparius exposed to wastewater treatment plant (WWTP) effluents. Insect larvae represent a complex and low-weight matrix that required the use of a miniaturized Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method of extraction followed by nanoLC-HRMS to perform the analysis. The optimization of this coupling in terms of separation conditions including trapping step, detection conditions and data treatment provided reproducible fingerprints on insect larvae exposed to WWTP effluents with both in situ and ex-situ approaches. Statistical treatments such as principal component analysis highlighted the impact of WWTP effluents on the metabolome of insect larvae and showed the influence of exposure conditions. The identification of discriminating signals (m/z, tR) matched with several potential endogenous biomarkers. These are mainly fatty acids, indicating a change in lipid metabolism that can be correlated with exposure to WWTP effluents. Several xenobiotics have also been detected, including ibuprofen and propranolol, whose identities have been confirmed by analytical standards. This work demonstrates the effectiveness and sensitivity of nanoLC-HRMS based environmental non-targeted approaches in ecotoxicological studies and provides the first profiling data for a very small aquatic invertebrate

Synthesis of new poly(ether ketone)s derived from biobased diols

International audienceThumbnail image of graphical abstract A new class of poly(ether ketone)s (PEKs) is prepared by polycondensation of various diols produced from biomass and various difluoro aromatics. After optimization of the reaction conditions, polycondensation of isosorbide and 4,4′-difluorodiphenylketone (2a) gives PEK1 with a high yield, moderate viscosity (0.31 dL g−1), and a glass-transition temperature (Tg) of 170 °C. The optimum conditions are applied to the synthesis of a series of PEKs (PEK 2-9) from difluoro agents and sugar diols. The polycondensation of isomannide (1b) with 1,4-di(p-fluorobenzoyl)benzene (2b) gives the best results with an inherent viscosity of 0.52 dL g−1 and the mass spectrum shows an abundance of cyclic structures. Similar conditions are used for the preparation of high-molar-mass copoly(ether ketone)s from a stoechiometric mixture of isosorbide/bisphenol-A

Untargeted analysis of nanoLC-HRMS data by ANOVA-PCA to highlight metabolites in Gammarus fossarum after in vivo exposure to pharmaceuticals

International audienc

Dianhydrohexitol based diamines for the synthesis and characterization of biosourced polymers

International audienc

Suspect screening of emerging pollutants in groundwater and runoff water using passive sampling coupled with high resolution mass spectrometry

International audienc

Nanochromatography coupled to high resolution mass spectrometry to investigate the metabolomic of benthic invertebrates exposed to wastewater treatment plant effluents

National audienc