Publications by authors named "Patrick Chaimbault"

The study of the dialogue between microorganisms at the molecular level is becoming essential to understand their relationship (antagonist, neutral, or beneficial interactions) and its impact on the organization of the microbial community. Mass spectrometry imaging (MSI) with matrix-assisted laser desorption/ionization (MALDI) is a technique that reveals the spatial distribution of molecules on a sample surface that may be involved in interactions between organisms. An experimental limitation to perform MALDI MSI is a flat sample surface, which in many cases could not be achieved for bacterial colonies such as filamentous bacteria (e.

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Chronic diseases such as cystic fibrosis, inflammatory bowel diseases, rheumatoid arthritis, and cardiovascular illness have been linked to a decrease in selenium levels and an increase in oxidative stress. Selenium is an essential trace element that exhibits antioxidant properties, with selenocysteine enzymes like glutathione peroxidase being particularly effective at reducing peroxides. In this study, a series of synthetic organoselenium compounds were synthesized and evaluated for their potential antioxidant activities.

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Article Synopsis
  • This review discusses the challenges and benefits of combining Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) with separation methods like gas and liquid chromatography and capillary electrophoresis.
  • * The synergy between FT-ICR MS and these separation techniques enhances analytical capabilities, especially in complex applications such as untargeted "Omics" (like proteomics and metabolomics), by improving mass measurement accuracy and resolution.
  • * It emphasizes that while integrating FT-ICR MS with separation methods is complex, it yields exceptional results, prompting discussions on its future amid ongoing technological advancements.
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As RNA post-transcriptional modifications are of growing interest, several methods were developed for their characterization. One of them established for their identification, at the nucleosidic level, is the hyphenation of separation methods, such as liquid chromatography or capillary electrophoresis, to tandem mass spectrometry. However, to our knowledge, no software is yet available for the untargeted identification of RNA post-transcriptional modifications from MS/MS data-dependent acquisitions.

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During a previous study that identified plants used in traditional medicine in Togo to treat infectious diseases, was specifically reported to treat intertrigo and candidiasis. Consequently, to explore the anti-infective potential of this plant, we investigated the antibacterial and the antifungal activity of the plant's parts, as well as the cytotoxic activities of raw extracts and subsequent fractions, and the chemical composition of the most active fractions. In order to evaluate the antimicrobial activity, MICs were determined using the broth dilution method.

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Homemade capillaries are a very common practice for the users of capillary electrophoresis (CE), notably in CE-UV. With the advent of the capillary electrophoresis-mass spectrometry coupling since the end of the 1980s, several interfaces have been developed. Among those interfaces, the porous tip sprayer allows great sensitivity at nano flow rates and has been used in numerous applications over the past few years.

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Article Synopsis
  • Researchers explored how to effectively identify RNA modifications using mass spectrometry coupled with separation methods, highlighting the need for a standard protocol in RNA characterization.
  • The study focused on optimizing the dephosphorylation step for tRNA from B. taurus, testing two protocols based on incubation time and the amount of bacterial alkaline phosphatase (BAP) used.
  • One protocol successfully achieved full dephosphorylation in 4 hours with 7.5 U of BAP, while a more economical method required only 3.0 U of BAP after overnight incubation, both ensuring no loss of analytes for future analyses.
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Lavranos (Family Asclepiadaceae) is an endemic herb in Yemen and Saudi Arabia, traditionally used to treat diabetes, abdominal pain, and stomach ulcers. Different extracts, fractions, and main constituents of were evaluated for their inhibitory activity against key enzymes in diabetes and hyperlipidemia, i.e.

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The bacteria of the genus and Basidiomycete fungi harbor many biosynthetic gene clusters (BGCs) that are at the origin of many bioactive molecules with medical or industrial interests. Nevertheless, most BGCs do not express in standard lab growth conditions, preventing the full metabolic potential of these organisms from being exploited. Because it generates biotic cues encountered during natural growth conditions, co-culture is a means to elicit such cryptic compounds.

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  • Researchers developed a new method to screen for iron-chelating peptides from protein hydrolysates using ion-pair reverse phase liquid chromatography (IP-RPLC) and high-resolution mass spectrometry (HRMS).
  • The process involves mixing peptides with iron(II) to form complexes, followed by comparative mass analysis of the samples to identify peptides that bind iron efficiently.
  • This new protocol successfully detected specific peptides, like GGH, in complex mixtures, indicating its effectiveness for discovering iron(II)-chelating peptides in food sources, while achieving a limit of detection as low as 0.77 mg/L.
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  • Two new compounds, 5-Hydroxy-1H-indole and D-pinitol, were isolated from the Calycotome spinosa plant, alongside three known flavonoids.
  • The novel alkaloid showed excellent antioxidant properties, outperforming standard antioxidants in various assays such as DPPH and total antioxidant capacity.
  • Additionally, the new compound exhibited significant antibacterial activity against multiple bacteria, indicating its potential for further applications in health or medicinal fields.
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A healthy ageing process is important when it is considered that one-third of the population of Europe is already over 50 years old, although there are regional variations. This proportion is likely to increase in the future, and maintenance of vitality at an older age is not only an important measure of the quality of life but also key to participation and productivity. So, the binomial "nutrition and ageing" has different aspects and poses considerable challenges, providing a fertile ground for research and networks.

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Nitrogen and its numerous hydrogenated and oxygenated derivatives are of main importance in our environment and in living cells as well in both qualitative and quantitative aspects. Their monitoring is needed to evaluate all disturbances occurring in the nitrogen cycle and in pathophysiological events related to variations of nitric oxide (NO) bioavailability. Many analytical methods are devoted to the measurement of nitrogen species, especially those related to NO, in the environmental, biological and pharmacological fields, and they have already been compiled and discussed in numerous reviews.

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Rationale: The potency of S-nitrosoglutathione (GSNO) as a nitric oxide (NO) donor to treat cardiovascular diseases (CVDs) has been highlighted in numerous studies. In order to study its bioavailability after oral administration, which represents the most convenient route for the chronic treatment of CVDs, it is essential to develop an analytical method permitting (i) the simultaneous measurement of GSNO metabolites, i.e.

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Ethnopharmacological Relevance: Pterocarpus erinaceus has been chosen based on ethnobotanical surveys carried out in the Tchamba district of the Republic of Togo.

Aim Of The Study: Investigation of the antibacterial as well as cytotoxic activities of whole extracts, fractions and compounds isolated from the leaves, trunk bark and roots of Pterocarpus erinaceus.

Materials And Methods: Bio-guided fractionation of the raw extracts of plant parts and subsequent isolation of compounds from active fractions using normal phase open column chromatography.

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Polysulfanes show chemopreventive effects against gastrointestinal tumors. We identified diallyl tetrasulfide and its derivative, dibenzyl tetrasulfide (DBTTS), to be mitotic inhibitors and apoptosis inducers. Here, we translate their application in colorectal cancer (CRC).

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Plant response to their environment stresses is a complex mechanism involving secondary metabolites. Stilbene phytoalexins, namely resveratrol, pterostilbene, piceids and viniferins play a key role in grapevine (Vitis vinifera) leaf defense. Despite their well-established qualities, conventional analyses such as HPLC-DAD or LC-MS lose valuable information on metabolite localization during the extraction process.

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In this review, we will present the different aspects of coumarins and derivatives, from natural origins or synthetically prepared, and their action on inflammation. Coumarins and also furo- and pyranocoumarins are found in many different plants. These compounds are very often investigated for antioxidant properties.

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Quinones and quinones-like compounds are potential candidates for the inhibition of CDC25 phosphatases. The combination of MALDI-MS analyses and biological studies was used to develop a rapid screening of a targeted library of indeno[1,2-b]indoloquinone derivatives. The screening protocol using MALDI-TOFMS and MALDI-FTICRMS highlighted four new promising candidates.

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Article Synopsis
  • Cell division cycle dual phosphatases (CDC25) regulate cell progression and are over-expressed in various cancers, with three isoforms: CDC25A, B, and C.
  • New compounds called 2-(thienothiazolylimino)-1,3-thiazolidin-4-ones were created to inhibit CDC25 phosphatase, and one compound (6) showed a significant inhibitory effect on CDC25A.
  • Compound 6 not only inhibited CDC25A in vitro but also caused growth arrest in cancer cell lines MCF7 and MDA-MB-231, marking the first time these 4-thiazolidinone derivatives have been identified as potential CDC25 inhibitors.
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Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures.

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Complementary analytical methods have been used to study the effect of potassium on the pyrolysis mechanisms of cellulose and lignocellulosic biomasses. Thermogravimetry, calorimetry, high-temperature (1) H NMR spectroscopy (in situ and real-time analysis of the fluid phase formed during pyrolysis), and water extraction of quenched char followed by size-exclusion chromatography coupled with mass spectrometry have been combined. Potassium impregnated in cellulose suppresses the formation of anhydrosugars, reduces the formation of mobile protons, and gives rise to a mainly exothermic signal.

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Photodynamic therapy (PDT) is a cancer treatment modality that requires three components, namely light, dioxygen and a photosensitizing agent. After light excitation, the photosensitizer (PS) in its excited state transfers its energy to oxygen, which leads to photooxidation reactions. In order to improve the selectivity of the treatment, research has focused on the design of PS covalently attached to a tumor-targeting moiety.

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To investigate the in-situ response to a stress, grapevine leaves have been subjected to mass spectrometry imaging (MSI) experiments. The Matrix Assisted Laser Desorption/Ionisation (MALDI) approach using different matrices has been evaluated. Among all the tested matrices, the 2,5-dihydroxybenzoic acid (DHB) was found to be the most efficient matrix allowing a broader range of detected stilbene phytoalexins.

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Article Synopsis
  • Thiazolidinediones, like ∆2-pioglitazone, show potential anti-cancer effects by inhibiting the growth of various cancer cell types, including human adenocarcinoma cells.
  • In HCT116 cells, ∆2-pioglitazone reduced growth without causing apoptosis, instead promoting autophagy and increasing the production of reactive oxygen and nitrogen species while decreasing glutathione levels.
  • The drug's effectiveness is linked to the activation of the Nrf2/Keap1 pathway, which boosts the levels of key antioxidant enzymes, suggesting a protective cellular response.
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