Search results for "DEPS"

N-acyl-homoserine-lactone quorum sensing in tomato phytopathogenic Pseudomonas spp. is involved in the regulation of lipodepsipeptide production

2012

Pseudomonas corrugata and Pseudomonas mediterranea are two closely related phytopathogenic bacteria both causal agents of tomato pith necrosis. P. corrugata produces phytotoxic and antimicrobial cationic lipodepsipeptides (LDPs) which are thought to act as major virulence factors. Previous studies have demonstrated that P. corrugata CFBP 5454 has an N-acyl homoserine lactone (AHL) quorum sensing (QS) system PcoI/PcoR and that LDP production occurs at high population densities. No molecular studies on virulence have thus far been reported for P. mediterranea. In this study, we show that P. mediterranea also produces LDPs as well as possessing an AHL-dependent QS system, designated PmeI/PmeR,…

Study of enzymatic activity in human neuroblastoma cells SH-SY5Y exposed to zearalenone's derivates and beauvericin.

2021

Abstract Beauvericin (BEA), α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL), are produced by several Fusarium species that contaminate cereal grains. These mycotoxins can cause cytotoxicity and neurotoxicity in various cell lines and they are also capable of produce oxidative stress at molecular level. However, mammalian cells are equipped with a protective endogenous antioxidant system formed by no-enzymatic antioxidant and enzymatic protective systems such as glutathione peroxidase (GPx), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD). The aim of this study was evaluating the effects of α-ZEL, β-ZEL and BEA, on enzymatic GPx, GST, CAT and SOD activity in huma…

Antibacterial effects of enniatins J1 and J3 on pathogenic and lactic acid bacteria

2011

Abstract Enniatins (ENs) are N -methylated cyclohexadepsipeptides, secondary metabolites produced by various species of the genus Fusarium . They are known to act as antifungal, antiyeast and antibacterial and to possess antiinsecticidal and phytotoxic properties. In this study we evaluated for the first time the antibiotic effect of pure fractions of EN J 1 and J 3 on several pathogenic strains and lactic acid bacteria. The ENs J 1 and J 3 were purified from the fermentation extract of Fusarium solani growth on solid medium of wheat kamut, using the technique of the low pressure liquid chromatography (LPLC) followed by a semipreparative liquid chromatography (LC). The purity and the struct…

POLIMORFISMI GENETICI E SUSCETTIBILITA' INDIVIDUALE NELLO SVILUPPO DI ALLERGOPATIE RESPIRATORIE. EFFETTI DI DEPS ED ALLERGENI IN CELLULE DI EPITELIO …

2011

Antibacterial effect of the bioactive compound beauvericin produced by Fusarium proliferatum on solid medium of wheat.

2010

To obtain the bioactive compound beauvericin (BEA), Fusarium proliferatum CECT 20569 was grown on a solid medium of wheat, utilizing the technique of the solid state fermentation (SSF), being this mycotoxin purified by high performance liquid chromatography (HPLC) with a reverse phase semi-preparative column using as the mobile phase acetonitrile/water in gradient condition. The purity of the BEA was verified by analytical HPLC and liquid chromatography tandem mass spectrometry (LC/MS-MS). The pure fractions of BEA were utilized to determinate the antibiotic effects on several bacterial strains that are considered normally pathogens of the intestinal tract as: Escherichia coli, Enterococcus…

Evaluation of enniatins A, A1, B, B1 and beauvericin in Portuguese cereal-based foods.

2012

Sixty-one samples of Portuguese cereal-based foods were analysed for the occurrence of emerging mycotoxins called enniatins (A, A1, B and B1) and beauvericin. Samples were extracted with a mixture of acetonitrile/water (85/15, v/v) using an Ultra-Turrax homogeniser, and mycotoxins were detected with liquid chromatography coupled to a mass spectrometer. This method was validated and adequate values of recovery (70-103%) and relative standard deviation (15%) were obtained. Signal suppression/enhancement was studied and matrix-matched calibration used to minimise this effect, but no additional clean-up step was necessary. The mass spectrometer was operated in selected reaction monitoring (SRM)…

Natural occurrence of emerging Fusarium mycotoxins in feed and fish from aquaculture.

2014

A new analytical method for the simultaneous determination of enniatins (ENs) and beauvericin (BEA) in fish feed and fish tissues by liquid chromatography coupled to mass spectrometry with linear ion trap (LC-MS/MS-LIT) was developed. Results showed that the developed method is precise and sensitive. The presence of emerging Fusarium mycotoxins, ENs and BEA, was determined in samples of aquaculture fish and feed for farmed fish, showing that all feed samples analyzed were contaminated with mycotoxins, with 100% coexistence. In aquacultured fish samples, the highest incidence was found in edible muscle and liver. As for the exposure assessment calculated, it was found that average consumer i…

Application of Wastewater-Based Epidemiology for Tracking Human Exposure to Deoxynivalenol and Enniatins

2022

Wastewater-based epidemiology (WBE) is a promising biomonitoring approach with the potential to provide direct information on human intake and exposure to food contaminants and environmental chemicals. The aim of this study was to apply WBE while employing the normalization method for exploring human exposure to selected mycotoxins according to population biomarker 5-hydroxyindoleacetic acid (5-HIAA). This type of normalization technique has been previously used to detect various other compounds. However, to the best of our knowledge, this is the first study tracking human exposure to mycotoxins. A sensitive analytical methodology was developed to achieve reliable quantification of deoxyniv…

Study of locomotion response and development in zebrafish (Danio rerio) embryos and larvae exposed to enniatin A, enniatin B, and beauvericin.

2021

Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate food and feed resources, and are capable of inducing a wide range of toxicity. Here, we studied the developmental and behavioral toxicity in zebrafish (Danio rerio) embryos and larvae exposed to three mycotoxins: beauvericin (BEA), Enniatin A (ENN A), and Ennitain B (ENN B). Zebrafish embryos were collected after fertilization, treated individually from 1 to 6 dpf with BEA at 8, 16, 32 and, 64 μM and for both enniatins at 3.12, 6.25, 12.5 and, 25 μM. Mixture of mycotoxins were assayed as follows: i) for BEA + ENN A and BEA + ENN B at [32 + 12.5] μM and [16 + 6.25] μM; ii) for ENN A + ENN B at [12.5 + 12.5] …

Stereoselektive synthese von D-α-hydroxycarbonsäuren bzw. D-α-hydroxycarbonsäuren enthaltenden depsipeptiden aus L-aminosäuren

1985

Abstract Depsipeptides containing D-α-hydroxy carboxylic acids are efficiently synthesized by the reactions of L-α-halo-carboxylic acid esters (obtained from L-amino acids) with caesium salts of N-protected amino acids.