Selenoneine-inspired selenohydantoins with glutathione peroxidase-like activity.

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. The new selenohydantoin molecules were inspired by selenoneine and synthesized using straightforward methods. Their antioxidant potential was evaluated and proven using classical radical scavenging and metal-reducing methods. The selenohydantoin derivatives exhibited glutathione peroxidase-like activity, reducing hydroperoxides. Theoretical calculations using Density Functional Theory (DFT) revealed the selenone isomer to be the only one occurring in solution, with selenolate as a possible tautomeric form in the presence of a basic species. Cytocompatibility assays indicated that the selenohydantoin derivatives were non-toxic to primary human aortic smooth muscle cells, paving the way for further biological evaluations of their antioxidant activity. The results suggest that selenohydantoin derivatives with trifluoro-methyl (-CF3) and chlorine (-Cl) substituents have significant activities and could be potential candidates for further biological trials. These compounds may contribute to the development of effective therapies for chronic diseases such cardiovascular diseases.

Hyphenation of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with separation methods: The art of compromises and the possible - A review.

This review provides an overview of the online hyphenation of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) with separation methods to date. The online coupling between separation techniques (gas and liquid chromatography, capillary electrophoresis) and FT-ICR MS essentially raises questions of compromise and is not look as straightforward as hyphenation with other analyzers (QTOF-MS for instance). FT-ICR MS requires time to reach its highest resolving power and accuracy in mass measurement capabilities whereas chromatographic and electrophoretic peaks are transient. In many applications, the strengths and the weaknesses of each technique are balanced by their hyphenation. Untargeted "Omics" (e.g. proteomics, metabolomics, petroleomics, …) is one of the main areas of application for FT-ICR MS hyphenated to online separation techniques because of the complexity of the sample. FT-ICR MS achieves the required high mass measurement accuracy to determine accurate molecular formulae and resolution for isobar distinction. Meanwhile separation techniques highlight isomers and reduce the ion suppression effects extending the dynamic range. Even if the implementation of FT-ICR MS hyphenated with online separation methods is a little trickier (the art of compromise), this review shows that it provides unparalleled results to the scientific community (the art of the possible), along with raising the issue of its future in the field with the relentless technological progress.

Nucleos'ID: A New Search Engine Enabling the Untargeted Identification of RNA Post-transcriptional Modifications from Tandem Mass Spectrometry Analyses of Nucleosides.

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. Thus, very long and tedious manual data interpretations are required. To meet the need of easier and faster data interpretation, a new user-friendly search engine, called Nucleos'ID, was developed for CE-MS/MS and LC-MS/MS users. Performances of this new software were evaluated on CE-MS/MS data from nucleoside analyses of already well-described Saccharomyces cerevisiae transfer RNA and Bos taurus total tRNA extract. All samples showed great true positive, true negative, and false discovery rates considering the database size containing all modified and unmodified nucleosides referenced in the literature. The true positive and true negative rates obtained were above 0.94, while the false discovery rates were between 0.09 and 0.17. To increase the level of sample complexity, untargeted identification of several RNA modifications from Pseudomonas aeruginosa 70S ribosome was achieved by the Nucleos'ID search following CE-MS/MS analysis.

Daniellia oliveri (Rolfe) Hutch and Dalziel: Antimicrobial Activities, Cytotoxicity Evaluation, and Phytochemical Identification by GC-MS.

During a previous study that identified plants used in traditional medicine in Togo to treat infectious diseases, Daniellia oliveri 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. Then, the most active fractions were evaluated for cytotoxicity by using normal human cells (MRC-5 cells) via the MTT assay. Finally, the most active and not toxic fractions were phytochemically investigated by GC-MS. Interestingly, all the raw extracts and fractions were active against the bacteria tested, with MICs ranging from 16 µg/mL to 256 µg/mL, while no antifungal activity was observed at 256 µg/mL, the highest tested concentration. Moreover, no toxicity was observed with most of the active fractions. The subsequent chemical investigation of the most interesting fractions led to identifying terpenes, phytosterols, phenolic compounds, and fatty acids as the main compounds. In conclusion, this study demonstrated that D. oliveri possesses valuable antibacterial activities in accordance with traditional use.

Protocol for Etching Bare-Fused Silica Capillaries for Sheathless Capillary Electrophoresis-Mass Spectrometry Coupling.

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. However, the homemade implementation of a suitable capillary for the porous tip sprayer is more challenging. The porous tip is created by etching the bare-fused silica capillary with hydrofluoric acid. Here we describe the complete process of etching bare-fused silica capillaries, from length cutting to quality control of the newly etched capillary.

Optimization of nucleotides dephosphorylation for RNA structural characterization by tandem mass spectrometry hyphenated with separation methods.

As part of RNA characterization, the identification of post-transcriptional modifications can be performed using hyphenation of separation methods with mass spectrometry. To identify RNA modifications with those methods, a first total digestion followed by a dephosphorylation step are usually required to reduce RNA to nucleosides. Even though effective digestion and dephosphorylation are essential to avoid further complications in analysis and data interpretation, to our knowledge, no standard protocol is yet referenced in the literature. Therefore, the aim of this work is to optimize the dephosphorylation step using a total extract of transfer RNA (tRNA)1 from B. taurus as a model and to determine and fix two protocols, leading to complete dephosphorylation, based on time and bacterial alkaline phosphatase (BAP)2 consumptions. Capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) was used to estimate the dephosphorylation efficiency of both protocols on many canonical and modified nucleotides. For a timesaving protocol, we established that full dephosphorylation was obtained after a 4-hour incubation at 37 °C with 7.5 U of BAP for 1 µg of tRNA. And for a BAP-saving protocol, we established that full dephosphorylation was obtained 3.0 U of BAP after an overnight incubation at 37 °C. Both protocols are suitable for quantitative analyses as no loss of analytes is expected. Moreover, they can be widely used for all other RNA classes, including messenger RNA or ribosomal RNA.

New Pregnane Glycosides Isolated from Caralluma hexagona Lavranos as Inhibitors of α-Glucosidase, Pancreatic Lipase, and Advanced Glycation End Products Formation.

Caralluma hexagona 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 C. hexagona were evaluated for their inhibitory activity against key enzymes in diabetes and hyperlipidemia, i.e., α-glucosidase and pancreatic lipase. In addition, the antioxidative effect and inhibition of advanced glycation end products (AGEs) were also assayed. Using a bioguided approach, the crude aqueous, methanolic extracts, methylene chloride (CH2Cl2), Diaion HP20 50% MeOH (DCF-1), and 100% MeOH (DCF-2) fractions of C. hexagona were evaluated for their possible α-glucosidase and pancreatic lipase inhibition and antioxidant activity. In addition, inhibition of AGE generation using bovine serum albumin (BSA)-fructose, BSA-methylglyoxal, and arginine-methylglyoxal models was carried out. Moreover, the main constituents of the most active fraction were isolated and identified using different chromatographic and sprectroscopic methods. From the most active CH2Cl2 fraction, four new pregnane glycosides were isolated and identified as 12ß-O-benzoyl 3ß,8ß,12ß,14ß,20-pentahydroxy-(20S)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside (1), 3ß,8ß,14ß,20-tetrahydroxy-(20S)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside-20-O-3-isoval-ß-d-glucopyranoside (2), 3ß,8ß,14ß,20-tetrahydroxy-(20R)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside-20-O-3-isoval-4-benzoyl-ß-d-glucopyranoside (3A), and 3ß,8ß,14ß,20-tetrahydroxy-(20R)-pregn-5-ene-3-O-ß-d-glucopyranosyl-(1 → 4)-O-ß-d-digitaloside-20-O-3,4 di-benzoyl-ß-d-glucopyranoside (3B). Among the tested samples, the highest trolox equivalent (TE) antioxidant capacity (TEAC) was observed for DCF-1 with values of 128.53 ± 5.07, 378.58 ± 5.19, and 106.71 ± 5.66 µM TE/mg using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant potential (FRAP) assays, respectively. The isolated apigenin-8-C-neohesperoside showed the highest antioxidant capacity (168.80 ± 1.80 and 278.21 ± 13.26 µM TE/mM) in DPPH and FRAP, respectively, while luteolin 4'-O-ß-d-neohesperidoside had the highest TEAC (599.19 ± 9.57 µM TE/mM) in ABTS assay. Compounds 1, 2, and the mixture 3A and 3B inhibited α-glucosidase with IC50 values of 0.92 ± 0.02, 0.67 ± 0.01, and 0.74 ± 0.02 mM, respectively. In the AGE assays, DCF-1 showed the highest inhibitory effect in BSA-fructose and arginine-methylglyoxal models with IC50 values of 0.39 ± 0.02 and 0.77 ± 0.10 mg/mL, respectively. Among the isolated compounds, flavonoid compounds showed the highest antiglycation effect, while pregnanes revealed higher α-glucosidase inhibition. In conclusion, the current study revealed that C. hexagona is a promising Yemeni natural remedy, of which the major content of pregnane glycosides and flavonoids could be considered as a new therapeutic candidate targeting the metabolic syndrome.

Metabolomics approach based on LC-HRMS for the fast screening of iron(II)-chelating peptides in protein hydrolysates.

Production of iron-chelating peptides from protein hydrolysates requires robust and adequate screening methods to optimize their purification and subsequently valorize their potential antioxidant properties. An original methodology was developed for direct and sensitive screening of iron(II)-chelating peptides based on ion-pair reverse phase liquid chromatography (IP-RPLC) coupled to high-resolution mass spectrometry (HRMS). Peptide mixture was first added to iron(II) solution to form iron(II)-peptide complexes. Then IP-RPLC-HRMS analysis was conducted on this iron-peptide mixture and on the iron-free peptide solution for comparative mass spectra analysis. This protocol, initially applied to a range of low molecular weight standard peptides, allowed detection of [(Peptide-H)+56FeII]+ complex ion for iron(II)-chelating peptides (GGH, EAH, DAH, ßAH, DMH, DTH, DSH). GGH was added in complex peptide mixtures and targeted analysis of [(GGH-H)+56FeII]+ complex showed a limit of detection (LOD) below 0.77 mg L-1 of GGH. This protocol was finally tested in combination with metabolomics software and additional digital processing for non-targeted search for iron(II)-chelating peptides. Applicability of this new screening methodology has been validated by detection of GGH as iron(II)-chelating peptide when added at 0.77 mg L-1 in casein hydrolysate. Graphical abstract.

Elicitation of Antimicrobial Active Compounds by Streptomyces-Fungus Co-Cultures.

The bacteria of the genus Streptomyces 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. In this study, we explored 72 different Streptomyces-fungus interaction zones (SFIZs) generated during the co-culture of eight Streptomyces and nine fungi. Two SFIZs were selected because they showed an elicitation of anti-bacterial activity compared to mono-cultures. The study of these SFIZs showed that co-culture had a strong impact on the metabolic expression of each partner and enabled the expression of specific compounds. These results show that mimicking the biotic interactions present in this ecological niche is a promising avenue of research to explore the metabolic capacities of Streptomyces and fungi.

New approach in the characterization of bioactive compounds isolated from Calycotome spinosa (L.) Link leaves by the use of negative electrospray ionization LITMSn, LC-ESI-MS/MS, as well as NMR analysis.

Two novel compounds were isolated for the first time from Calycotome spinosa (L.) Link, an alkaloid 5-Hydroxy-1H-indole (4) and a cyclitol D-pinitol (5), together with the three well-known flavonoids; Chrysin-7-O-(ß-D-glucopyranoside) (1), Chrysin-7-O-ß-D-(6″-acetyl)glycopyranoside (2) and Apigenin-7-O-ß-D-glycopyranoside (3). The chemical structures of the isolated compounds were elucidated by spectroscopic data and mass spectrometric analyses; including a fresh approach 1D-NMR, 2D-NMR with LC-ESI-MS/MS. In this study, the new compound (4) that has been obtained from the leaves MeOH extract presented the best radical scavenging activity (DPPH) (IC50 < 10 µg/mL) compared to the standard butylated hydroxytoluene (BHT, IC50 = 34.73 ± 0.23 µg/mL) and showed the highest total antioxidant capacity (TAC = 985.54 ± 0.13 mg AAE/g extract) in contrast to ascorbic acid (TAC = 905.95 ± 0.07 mg AAE/g extract). Furthermore, the strongest reducing power (EC50 = 344.82 ± 0.02 µg/mL), as well as the remarkable scavenging potential by ABTS assay (IC50 = 7.8 ± 0.43 µg/mL), were exhibited by the same composite (4). Followed by the methanol crude extract and the compound (3) that also showed a potent antioxidant (DPPH; IC50 = 41.04 ± 0.15 and 47.36 ± 0.21 µg/mL, TAC; 671.02 ± 0.21 and 608.67 ± 0.34 mg AAE/g extract, FRAP; EC50 = 763.73 ± 0.32 and 814.61 ± 0.31 µg/mL, ABTS; IC50 = 19.18 ± 0.06 and 63.72 ± 0.64 µg/mL, respectively), but less than the previous samples. On the opposite side, compound (5) had the lowest activity, in which its values were less interesting to determine. Moreover, compound (4) has equally exerted an attractive antibacterial activity against Staphylococcus aureus (ATTC-25923), Pseudomonas aeruginosa (ATTC- 27853) and Salmonella abony (NCTC 6017), as measured by the disc diffusion assay, with inhibition zones of 16 ± 0.5, 9.83 ± 0.29 and 8 ± 0.28 mm, in that order. To the best of our knowledge, 5-Hydroxy-1H-indole was isolated from plants for the second time in our current work. Thus, the obtained results from this investigation propose that the leaves of C. spinosa are a rich natural source for value molecules as potential antioxidants and antimicrobial agents for best human health.

Personalized nutrition in ageing society: redox control of major-age related diseases through the NutRedOx Network (COST Action CA16112).

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. The NutRedOx network will focus on the impact of redox-active compounds in food on healthy ageing, chemoprevention, and redox control in the context of major age-related diseases. The main aim of the NutRedOx network is to gather experts from Europe, and neighbouring countries, and from different disciplines that are involved in the study of biological redox active food components and are relevant to the ageing organism, its health, function, and vulnerability to disease. Together, these experts will form a major and sustainable EU-wide cluster in form of the NutRedOx Centre of Excellence able to address the topic from different perspectives, with the long-term aim to provide a scientific basis for improved nutritional and lifestyle habits, to train the next generation of multidisciplinary researchers in this field, to raise awareness of such habits among the wider population, and also to engage with industry to develop age-adequate foods and medicines.

Labeling nitrogen species with the stable isotope 15N for their measurement by separative methods coupled with mass spectrometry: A review.

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. Nitrogen isotope (15N) is stable and has a low level of natural abundance. Labeling nitrogen species with 15N associated with mass spectrometry (MS) gives rise to more mechanistic information and improved analytical performances compared to conventional methods. The present review is dedicated to the 15N labeling of related nitrogen species to monitor their interconversion and metabolism, the different chemical probes used for their derivatization and the corresponding separative methods coupled with MS for analyzing resulting adducts. The fragmentation mode of the different adducts and the resulting selectivity and sensitivity are discussed.

Higher-energy collision-induced dissociation for the quantification by liquid chromatography/tandem ion trap mass spectrometry of nitric oxide metabolites coming from S-nitroso-glutathione in an in vitro model of the intestinal barrier.

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. nitrite, S-nitrosothiols (RSNOs) and nitrate and (ii) to distinguish them from other sources (endogenous synthesis and diet). METHODS: Exogenous GSNO was labeled with 15 N, and the GS15 NO metabolites after conversion into the nitrite ion were derivatized with 2,3-diaminonaphthalene. The resulting 2,3-naphthotriazole was quantified by liquid chromatography/tandem ion trap mass spectrometry (LC/ITMS/MS) in multiple reaction monitoring mode after Higher-energy Collision-induced Dissociation (HCD). Finally, the validated method was applied to an in vitro model of the intestinal barrier (monolayer of Caco-2 cells) to study GS15 NO intestinal permeability. RESULTS: A LC/ITMS/MS method based on an original transition (m/z 171 to 156) for sodium 15 N-nitrite, GS15 NO and sodium 15 N-nitrate measurements was validated, with recoveries of 100.8 ± 3.8, 98.0 ± 2.7 and 104.1 ± 3.3%, respectively. Intra- and inter-day variabilities were below 13.4 and 12.6%, and the limit of quantification reached 5 nM (signal over blank = 4). The permeability of labeled GS15 NO (10-100 µM) was evaluated by calculating its apparent permeability coefficient (Papp ). CONCLUSIONS: A quantitative LC/ITMS/MS method using HCD was developed for the first time to selectively monitor GS15 NO metabolites. The assay allowed evaluation of GS15 NO intestinal permeability and situated this drug candidate within the middle permeability class according to FDA guidelines. In addition, the present method has opened the perspective of a more fundamental work aiming at studying the fragmentation mechanism leading to the ion at m/z 156 in HCD tandem mass spectrometry in the presence of acetonitrile.

Antibacterial activity and cytotoxicity of Pterocarpus erinaceus Poir extracts, fractions and isolated compounds.

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. The broth microdilution method was used to evaluate the antibacterial activity, based on the determination of Minimal Inhibitory Concentrations (MICs) against several bacterial species representative of the most commonly encountered infectious diseases worldwide. The cytotoxicity of the raw extract and the most active fractions on a human non-cancerous cell (namely MRC-5) was estimated with a MTT assay. The chemical structure of the compounds isolated was elucidated using a combination of advanced Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS). RESULTS: All extracts and fractions tested have shown good activities against Gram-positive bacteria (including Methicillin-Resistant Staphylococcus aureus, MRSA) and against Pseudomonas aeruginosa with MIC values ranging from 32µg/mL to 256µg/mL. In contrast, extracts were not toxic to MRC-5 cells. Four compounds have been isolated: Compound 1 (friedeline); Compound 2 (2,3 dihydroxypropyloctacosanoate); Compound 3 (a mixture of ß-sitosterol, stigmasterol and campesterol); Compound 4 (ß-sitosteryl-ß-D-glucopyranoside) and shown to be active against some of the bacteria tested. They were active with MIC equal to 4µg/mL against strains of S. aureus (including MRSA). To the best of our knowledge, all of them except friedeline have never been reported in this plant species. CONCLUSION: P. erinaceus is confirmed as a plant harboring promising antibacterial activity with activities against serious human pathogens at very low concentrations. Some of the compounds isolated are also active at concentrations as low as 4µg/mL and therefore, may provide new leads for the development of antibacterial agents.

Tubulin-binding anticancer polysulfides induce cell death via mitotic arrest and autophagic interference in colorectal cancer.

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). MALDI-TOF-MS analysis identified both compounds as reversible tubulin binders, validated by in cellulo α-tubulin degradation. BRAF(V600E)-mutated HT-29 cells were resistant to DBTTS, as evidenced by mitotic arrest for 48 h prior to apoptosis induction compared to KRAS(G12V)-mutated SW480/620 cells, which committed to death earlier. The prolonged mitotic block correlated with autophagy impairment and p62 protein accumulation in HT-29 but not in SW480/620 cells, whereas siRNA-mediated p62 inhibition sensitized HT-29 cells to death. In silico analysis with 484 colorectal cancer patients associated higher p62 expression and reduced autophagic flux with greater overall survival. Accordingly, we hypothesized that DBTTS targets CRC survival/death through autophagy interference in cell types with differential autophagic capacities. We confirmed the therapeutic potential of DBTTS by the inhibition of spheroid and colony formation capacities in CRC cells, as well as in HT-29 zebrafish xenografts in vivo.

Correlative Analysis of Fluorescent Phytoalexins by Mass Spectrometry Imaging and Fluorescence Microscopy in Grapevine Leaves.

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. To overcome this issue, a correlative analysis combining mass spectroscopy imaging (MSI) and fluorescence imaging was developed to localize in situ stilbenes on the same stressed grapevine leaves. High-resolution images of the stilbene fluorescence provided by macroscopy were supplemented by specific distributions and structural information concerning resveratrol, pterostilbene, and piceids obtained by MSI. The two imaging techniques led to consistent and complementary data on the stilbene spatial distribution for the two stresses addressed: UV-C irradiation and infection by Plasmopara viticola. Results emphasize that grapevine leaves react differently depending on the stress. A rather uniform synthesis of stilbenes is induced after UV-C irradiation, whereas a more localized synthesis of stilbenes in stomata guard cells and cell walls is induced by P. viticola infection. Finally, this combined imaging approach could be extended to map phytoalexins of various plant tissues with resolution approaching the cellular level.

Natural and Synthetic Coumarins with Effects on Inflammation.

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. Other biological properties are also possible and anti-inflammation activity is one of these. As coumarins are also available quite easily via synthesis, natural ones can be prepared this way but derivatives with special substituents are also feasible. A review on the same topic appeared in 2004 and our contribution will take into account everything published since then.

Screening of indeno[1,2-b]indoloquinones by MALDI-MS: a new set of potential CDC25 phosphatase inhibitors brought to light.

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. Biological investigations showed that only compounds 5c-f inhibited CDC25A and -C phosphatases, with IC50 values around the micromolar range. The direct use of a screening method based on MALDI-MS technology allowed achieving fast scaffold identification of a new class of potent inhibitors of CDC25 phosphatases. These four molecules appeared as novel molecules of a new class of CDC25 inhibitors. Assessment of 5c-e in an MRC5 proliferation assay provided an early indicator of toxicity to mammalian cells. Compound 5d seems the most promising hit for developing new CDC25 inhibitors.

2-(Thienothiazolylimino)-1,3-thiazolidin-4-ones inhibit cell division cycle 25 A phosphatase.

Cell division cycle dual phosphatases (CDC25) are essential enzymes that regulate cell progression in cell cycle. Three isoforms exist as CDC25A, B and C. Over-expression of each CDC25 enzyme is found in cancers of diverse origins. Thiazolidinone derivatives have been reported to display anti-proliferative activities, bactericidal activities and to reduce inflammation process. New 2-(thienothiazolylimino)-1,3-thiazolidin-4-ones were synthesized and evaluated as inhibitors of CDC25 phosphatase. Among the molecules tested, compound 6 inhibited CDC25A with an IC50 estimated at 6.2±1.0µM. The binding of thiazolidinone derivative 6 onto CDC25A protein was reversible. In cellulo, compound 6 treatment led to MCF7 and MDA-MB-231 cell growth arrest. To our knowledge, it is the first time that such 4-thiazolidinone derivatives are characterized as CDC25 potential inhibitor.

Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities.

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. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude "waste" plant materials for specific practical applications, especially-but not exclusively-in developing countries lacking a more sophisticated industrial infrastructure.