Search results for "Depsipeptide"
showing 10 items of 86 documents
Pseudomonas corrugata crpCDE is part of the cyclic lipopeptide corpeptin biosynthetic gene cluster and is involved in bacterial virulence in tomato a…
2014
Summary: Pseudomonas corrugataCFBP 5454 produces two kinds of cyclic lipopeptides (CLPs), cormycin A and corpeptins, both of which possess surfactant, antimicrobial and phytotoxic activities. In this study, we identified genes coding for a putative non-ribosomal peptide synthetase and an ABC-type transport system involved in corpeptin production. These genes belong to the same transcriptional unit, designated crpCDE. The genetic organization of this locus is highly similar to other PseudomonasCLP biosynthetic clusters. Matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis revealed that transporter and synthetase genomic knock-out mutants were u…
α,β-Dehydroamino acids in naturally occurring peptides
2014
α,β-Dehydroamino acids are naturally occurring non-coded amino acids, found primarily in peptides. The review focuses on the type of α,β-dehydroamino acids, the structure of dehydropeptides, the source of their origin and bioactivity. Dehydropeptides are isolated primarily from bacteria and less often from fungi, marine invertebrates or even higher plants. They reveal mainly antibiotic, antifungal, antitumour, and phytotoxic activity. More than 60 different structures were classified, which often cover broad families of peptides. 37 different structural units containing the α,β-dehydroamino acid residues were shown including various side chains, Z and E isomers, and main modifications: meth…
Intra- and intermolecular forces dependent main chain conformations of esters of α,β-dehydroamino acids
2013
Abstract Esters of dehydroamino acids occur in nature. To investigate their conformational properties, the low-temperature structures of Ac-ΔAla-OMe, Ac-ΔVal-OMe, Z-(Z)-ΔAbu-OMe, and Z-(Z)-ΔAbu-NHMe were studied by single-crystal X-ray diffraction. The ΔAla ester prefers the fully extended conformation C5. Both the ΔVal and (Z)-ΔAbu esters assume the conformation β, whereas the amide analogue of the latter prefers the conformation α. For the conformations found, DFT calculations using B3LYP/6-311++G(d,p) with the SCRF-PCM and M062X/6-311++G(d,p) with the SCRF-SMD method were applied to mimicking chloroform and water environment. The tendency of the ΔVal and (Z)-ΔAbu esters towards the confo…
Influence of different soluble dietary fibers on the bioaccessibility of the minor Fusarium mycotoxin beauvericin.
2011
Abstract Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains and is known to have various biological activities. This study investigated the bioaccessibility of the BEA tested in concentrations of 5 and 25 mg/L, in a model solution and in wheat crispy breads elaborated with different natural binding compounds as the soluble alimentary dietary fibers β-1,3 glucan, chitosan low molecular weight (L.M.W.), chitosan medium molecular weight (M.M.W.), fructooligosaccharides (FOS), galattomannan, inulin and pectin, added at concentrations of 1% and 5%. The bioaccessibility was determinated by employing a simulated gastrointestinal digestion tha…
Transcriptome analysis of Pseudomonas mediterranea and P. corrugata plant pathogens during accumulation of medium-chain-length PHAs by glycerol bioco…
2017
Pseudomonas corrugata and P. mediterranea are soil inhabitant bacteria, generally living as endophytes on symptomless plants and bare soil, but also capable of causing plant diseases. They share a similar genome size and a high proteome similarity. P. corrugata produces many biomolecules which play an important role in bacterial cell survival and fitness. Both species produce different medium-chain-length PHAs (mcl-PHAs) from the bioconversion of glycerol to a transparent film in P. mediterranea and a sticky elastomer in P. corrugata. In this work, using RNA-seq we investigated the transcriptional profiles of both bacteria at the early stationary growth phase with glycerol as the carbon sou…
Biomonitoring of Enniatin B1 and Its Phase I Metabolites in Human Urine: First Large-Scale Study
2020
Enniatins (Enns) are mycotoxins produced by Fusarium spp. which are a fungus widely spread throughout cereals and cereal-based products. Among all the identified enniatins, Enn B1 stands as one of the most prevalent analogues in cereals in Europe. Hence, the aim of this study was to evaluate for the first time the presence of Enn B1 and its phase I metabolites in 300 human urine samples using an ultrahigh-performance liquid chromatography high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) methodology. Enn B1 was detected in 94.3% of samples ranging from 0.007 to 0.429 ng/mL (mean value: 0.065 ng/mL). In accordance with previous in vitro and in vivo analysis, hydroxylated metabolites …
Antifungal effects of the bioactive compounds enniatins A, A1, B, B1
2010
To produce enniatin (ENs), Fusarium tricinctum CECT 20150 was grown in a liquid medium of potato (PDB), being mycotoxin purified by high performance liquid chromatography (HPLC) with a reverse phase semipreparative column using a mobile phase of acetonitrile/water using gradient condition. The purity of the ENs fractions was verified by analytical HPLC and LC/MS-MS. The pure fractions of ENs were utilized to study the biological activity on several mycotoxigenic moulds as Fusarium verticilloides, Fusarium sporotrichioides, Fusarium tricinctum, Fusarium poae, Fusarium oxysporum, Fusarium proliferatum, Beauveria bassiana, Trichoderma harzianum, Aspergillus flavus, Aspergillus parasiticus, Asp…
Study of the potential toxicity of commercial crispy breads by evaluation of bioaccessibility and bioavailability of minor Fusarium mycotoxins
2011
Abstract Enniatins (ENs) are bioactive compounds produced by the secondary metabolism of several Fusarium strains and known to have several biological activities, such as acting as enzyme inhibitors, antifungal and antibacterial agents, and immunomodulatory substances. This study has investigated the ENs bioaccessibility, spiked in commercial wheat crispy bread at 1.5 and 3.0 μmol/g concentrations, their transepithelial transport and bioavailability using Caco-2 cells as a model of the human intestinal epithelium. The content (%) of the four ENs contained in the gastric fluid has resulted variable from 69% to 91%, considering the two concentrations assayed. The mean bioaccessibility data fo…
A chemical approach for the reduction of beauvericin in a solution model and in food systems.
2014
Abstract Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains with a strong antibacterial, antifungal, and insecticidal activities. This study evaluated the reduction of BEA added at 25 mg/kg in phosphate buffer saline (PBS) solutions at pH of 4, 7 and 10, or to different cereal products (kernels and flours) by the bioactive compounds phenyl isothiocyanate (PITC) and benzyl isothiocyanate (BITC). The concentration of the mycotoxin was evaluated using liquid chromatography coupled to the diode array detector (LC-DAD). In solution, BEA reduction ranged from 9% to 94% on a time-dependent fashion and lower pH levels resulted in higher BEA re…
Study of the potential toxicity of enniatins A, A(1), B, B(1) by evaluation of duodenal and colonic bioavailability applying an in vitro method by Ca…
2010
Abstract The bioavailability of the minor Fusarium mycotoxins enniatins (ENs) utilizing an in vitro method which allows the simulation of the small and large intestine tracts has been studied. This method, based on the application of the Caco-2 cells grown alone or in symbiosis with several strains characteristics of the gastrointestinal tract, has permitted to simulate the duodenal and colonic intestinal compartments, respectively. The duodenal bioavailability expressed as absorption value after 4 h of exposure, ranged from 57.7 to 76.8% for EN A, from 68.8 to 70.2% for EN A1, from 65.0 to 67.0% for EN B, and from 62.2 to 65.1% for EN B1. Colonic bioavailability after 48 h of incubation ra…