tenuazonic-acid and alternariol

Alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TeA) are the three major Alternaria toxin contaminants in food. In the present study, we conducted their single and combined toxicity analyses using human gastric epithelial cell line (GES-1) that was first exposed to the toxins when they entered the human body. By comparing the cytotoxicity IC50, we found that compared to several other mycotoxins with limit standards there was cytotoxicity DON > OTA > AME > AOH > ZEN > TeA. Further, we obtained combination index (CI)-isobologram equation by the Chou-Talalay method according to a toxin ratio of 1:1:2 and carried out the combined toxicity analysis of the three binary and ternary compounds, and the results showed that AOH + AME + TeA showed synergistic toxic effects. Based on the co-occurring status, we also carried out the combined toxicity analysis of AME and AOH at different ratios and found antagonistic effects at low cytotoxic concentrations as well as synergistic and additive effects at high concentrations. Also, we found that all three and their combinations caused apoptosis, activation of caspase-3 cleavage, activation of DNA damage pathways ATR-Chk1-P53 and ATM-Chk2-P53. In conclusion, we used GES-1 cells to inform the risk of coaction of AOH, AME, and TeA in dietary exposure.

Topics: Alternaria; Epithelial Cells; Food Contamination; Humans; Lactones; Mycotoxins; Tenuazonic Acid; Tumor Suppressor Protein p53

Due to the extensive potential of previously studied endophytes in addition to plants belonging to genus Physalis as a source of anti-inflammatory constituents, the present study aimed at isolation for the first time some endophytic fungi from the medicinal plant Physalis pruinosa.. The endophytic fungi were isolated from the fresh leaves of P. pruinosa then purified and identified by both morphological and molecular methods. Comparative evaluation of the cytotoxic and ex vivo anti-inflammatory activity in addition to gene expression of the three pro-inflammatory indicators (TNF-α, IL-1β and INF-γ) was performed in WBCs treated with lipopolysaccharide (LPS) for the identified endophytes, isolated compounds and the standard anti-inflammatory drug (piroxicam). For prediction of the binding mode of the top-scoring constituents-targets complexes, the Schrödinger Maestro 11.8 package (LLC, New York, NY) was employed in the docking study.. A total of 50 endophytic fungal isolates were separated from P. pruinosa leaves. Selection of six representative isolates was performed for further bioactivity screening based on their morphological characters, which were then identified as Stemphylium simmonsii MN401378, Stemphylium sp. MT084051, Alternaria infectoria MT573465, Alternaria alternata MZ066724, Alternaria alternata MN615420 and Fusarium equiseti MK968015. It could be observed that A. alternata MN615420 extract was the most potent anti-inflammatory candidate with a significant downregulation of TNF-α. Moreover, six secondary metabolites, alternariol monomethyl ether (1), 3'-hydroxyalternariol monomethyl ether (2), alternariol (3), α-acetylorcinol (4), tenuazonic acid (5) and allo-tenuazonic acid (6) were isolated from the most potent candidate (A. alternata MN615420). Among the tested isolated compounds, 3'-hydroxyalternariol monomethyl ether showed the highest anti-inflammatory potential with the most considerable reductions in the level of INF-γ and IL-1β. Meanwhile, alternariol monomethyl ether was the most potent TNF-α inhibitor. The energy values for the protein (IL-1β, TNF-α and INF-γ)-ligand interaction for the best conformation of the isolated compounds were estimated using molecular docking analysis.. The results obtained suggested alternariol derivatives may serve as naturally occurring potent anti-inflammatory candidates. This study opens new avenues for the design and development of innovative anti-inflammatory drugs that specifically target INF-γ, IL-1β and INF-γ.

Topics: Anti-Inflammatory Agents; Endophytes; Ethers; Molecular Docking Simulation; Physalis; Tenuazonic Acid; Tumor Necrosis Factor-alpha

Alternaria can infest pears to produce metabolites, which can contaminate pears and their processed products. Pear paste, one of the most important pear-based products, is popular among Chinese consumers especially for its cough relieving and phlegm removal properties. Although people are concerned about the risk of Alternaria toxins in many agro-foods and their products, little is known about the toxins in pear paste.. A method was developed for the determination of tenuazonic acid, alternariol, alternariol menomethyl ether, altenuene and tentoxin in pear paste by ultra-performance liquid chromatography tandem mass spectrometry with saturated sodium sulphate dissolution and acidified acetonitrile extraction. The mean recoveries of the five toxins were 75.3-113.8% with relative standard deviations of 2.8-12.2% at spiked levels of 1.0-100 μg kg. To the best of our knowledge, this is the first report on the detection method and residue levels of Alternaria toxins in pear paste. The proposed method and research data can provide technical support for the Chinese government to continuously monitor and control Alternaria toxins in pear paste, especially tenuazonic acid. It can also provide a useful reference for related researchers. © 2023 Society of Chemical Industry.

Topics: Alternaria; Chromatography, High Pressure Liquid; Chromatography, Liquid; Ethers; Food Contamination; Humans; Lactones; Liquid-Liquid Extraction; Mycotoxins; Pyrus; Solubility; Tandem Mass Spectrometry; Tenuazonic Acid

A quick and selective analytical method was developed via LC-MS/MS for the simultaneous quantitation of alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TeA) which belong to the large group of secondary metabolites produced by fungi of the genus Alternaria. Cocoa is susceptible to a number of toxin-producing microorganisms, including Aspergillus and Penicillium species. The method relies on a single-step extraction, followed by an easy clean up, dilution of the raw extract and direct analysis. To assess whether cocoa and chocolate products can be a source of Alternaria toxins, a monitoring of cocoa and chocolate products (N = 99) as well as cocoa raw and semi-finished materials (cocoa shells, cocoa masses; N = 10) was performed. As the results, cocoa and products made from cocoa (without other ingredients) are no source of the Alternaria toxins considered here.

Topics: Alternaria; Chocolate; Chromatography, Liquid; Food Contamination; Lactones; Mycotoxins; Tandem Mass Spectrometry; Tenuazonic Acid

Wheat is one of three major food crops in China. Alternaria species can cause spoilage of wheat with consequent mycotoxin accumulation. Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are the most common and frequently studied mycotoxins. There are limited regulations placed on Alternaria mycotoxin concentrations worldwide due to the lack of toxicity data available. More data on the levels of mycotoxin contamination are also needed. It is also important to reduce the risks of Alternaria mycotoxins.. One hundred and thirty-two wheat samples were collected from Hebei Province, China, and analyzed for AOH, AME, and TeA. Tenuazonic acid was found to be the predominant Alternaria mycotoxin, especially in flour samples. Studying Alternaria species that cause black-point disease of wheat indicated that Alternaria alternata and Alternaria tenuissima were the dominant species. Most of the Alternaria strains studied produced more than one mycotoxin and TeA was produced at the highest concentration, which may have resulted in the high level of TeA contamination in the wheat samples. Furthermore, magnolol displayed obvious antifungal and antimycotoxigenic activity against Alternaria. This is the first report on the antimycotoxigenic activity of magnolol against Alternaria species.. The Alternaria mycotoxin contamination levels in wheat and wheat products from Hebei Province, China, were correlated with the toxigenic capacity of the Alternaria strains colonizing the wheat. Considering its safety, magnolol could be developed as a natural fungicide in wheat, or as a natural alternative food preservative based on its strong antifungal and antimycotoxigenic activity against Alternaria strains. © 2020 Society of Chemical Industry.

Topics: Alternaria; Biphenyl Compounds; China; Flour; Food Contamination; Fungicides, Industrial; Lactones; Lignans; Plant Diseases; Tenuazonic Acid; Triticum

Fluorescent pseudomonads colonizing wheat ears have a high antagonistic potential against phytopathogenic fungi. To check this hypothesis, the bacterial antagonist Pseudomonas simiae 9

Topics: Alternaria; Antibiosis; Biological Control Agents; Fusarium; Lactones; Mycotoxins; Pseudomonas; Tenuazonic Acid; Trichothecenes; Triticum; Zearalenone

Topics: Alternaria; Animals; Consumer Product Safety; Dose-Response Relationship, Drug; Food Microbiology; Humans; Lactones; Mycotoxins; Risk Assessment; Risk Factors; Structure-Activity Relationship; Tenuazonic Acid; Toxicity Tests

Alternaria mycotoxins, such as tenuazonic acid (TeA), altenuene (ALT), alternariol (AOH), tentoxin (TEN) and alternariol monomethyl ether (AME) are frequently found in foods and may pose a potential risk to human health. Human biomonitoring can help measure our exposure to these mycotoxins, and help us determine if the exposure is changing over time. In this study, a simple liquid-liquid extraction sample preparation procedure followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous analysis of five Alternaria mycotoxins in human urine. High recoveries (92.7-103.2%) were obtained for all the tested mycotoxins with relative standard deviations (RSDs, %) of less than 6.4%. The limits of quantification (LOQs) for the analytes in urine ranged from 0.001 to 0.05 ng/mL. The method was successfully applied to investigate the levels of five Alternaria mycotoxins from 135 volunteers. In all of the samples, at least one Alternaria mycotoxin was detected. TeA, AME and AOH were the predominant Alternaria mycotoxins, and the detection rates were 85.9%, 96.3% and 51.9%, respectively.

Topics: Alternaria; Arylsulfatases; Chromatography, High Pressure Liquid; Food Contamination; Glucuronidase; Humans; Lactones; Limit of Detection; Liquid-Liquid Extraction; Mycotoxins; Peptides, Cyclic; Tandem Mass Spectrometry; Tenuazonic Acid

Large amounts of tomato fruits and derived products are produced in China and may be contaminated by Alternaria mycotoxins, which may have the potential risks for human health. There is thus an increasing interest in reducing the mycotoxins. In the present study, 26 Alternaria strains isolated from tomato black rots were identified according to morphological and molecular grounds, and their mycotoxigenic abilities for alternariol (AOH), alternariol monomethyl-ether (AME) and tenuazonic acid (TeA) were also investigated. The results showed that A. alternate was the predominant species with incidence values of 65.4% (17/26), followed by A. brassicae (7/26) and A. tenuissima (2/26). A. alternate isolates showed the highest capacity for AOH, AME and TeA production among the studied isolates either in vitro or in vivo, suggested that A. alternata may be the most important mycotoxin-producing species in tomato fruits. Thus, UV-C irradiation was used to reduce the mycotoxin produced by A. alternata in our study. The results showed that low dose of UV-C irradiation (0.25 kJ/m

Topics: Alternaria; China; Coumaric Acids; Fruit; Lactones; Mycotoxins; Propionates; Solanum lycopersicum; Tenuazonic Acid; Ultraviolet Rays

Alternaria species have been reported to infect a wide variety of vegetables, fruits, and cereal crops. Wheat is one of the most consumed cereal worldwide. A sensitive HPLC-DAD methodology was applied to quantify alternariol (AOH), alternariol methyl ether (AME) and tenuazonic acid (TeA) in 65 samples of whole wheat, bran, and flour. The extraction methodology allowed extracting the three toxins simultaneously. Limits of detection in wheat were 3.4, 4.5, and 0.5 µg kg

Topics: Alternaria; Argentina; Chromatography, High Pressure Liquid; Dietary Fiber; Flour; Food Contamination; Lactones; Limit of Detection; Mycotoxins; Tenuazonic Acid; Triticum

To observe the variation in accumulation of Fusarium and Alternaria mycotoxins across a topographically heterogeneous field and tested biotic (fungal and bacterial abundance) and abiotic (microclimate) parameters as explanatory variables.. We selected a wheat field characterized by a diversified topography, to be responsible for variations in productivity and in canopy-driven microclimate. Fusarium and Alternaria mycotoxins where quantified in wheat ears at three sampling dates between flowering and harvest at 40 points. Tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), deoxynivalenol (DON), zearalenone (ZEN) and deoxynivalenol-3-Glucoside (DON.3G) were quantified. In canopy temperature, air and soil humidity were recorded for each point with data-loggers. Fusarium spp. as trichothecene producers, Alternaria spp. and fungal abundances were assessed using qPCR. Pseudomonas fluorescens bacteria were quantified with a culture based method. We only found DON, DON.3G, TeA and TEN to be ubiquitous across the whole field, while AME, AOH and ZEN were only occasionally detected. Fusarium was more abundant in spots with high soil humidity, while Alternaria in warmer and drier spots. Mycotoxins correlated differently to the observed explanatory variables: positive correlations between DON accumulation, tri 5 gene and Fusarium abundance were clearly detected. The correlations among the others observed variables, such as microclimatic conditions, varied among the sampling dates. The results of statistical model identification do not exclude that species coexistence could influence mycotoxin production.. Fusarium and Alternaria mycotoxins accumulation varies heavily across the field and the sampling dates, providing the realism of landscape-scale studies. Mycotoxin concentrations appear to be partially explained by biotic and abiotic variables.. We provide a useful experimental design and useful data for understanding the dynamics of mycotoxin biosynthesis in wheat.

Topics: Alternaria; Food Contamination; Fusarium; Glucosides; Lactones; Microclimate; Mycotoxins; Pseudomonas fluorescens; Secondary Metabolism; Soil Microbiology; Tenuazonic Acid; Trichothecenes; Triticum; Zearalenone

Alternaria mycotoxins frequently contaminate agricultural crops and may impact animal and human health. However, data on mammalian metabolism and potential biomarkers of exposure for human biomonitoring (HBM) are scarce. Here, we report the preliminary investigation with respect to metabolism and excretion of Alternaria toxins in Sprague Dawley rats. Four animals were housed in metabolic cages for 24 h after gavage administration of an Alternaria alternata culture extract containing ten known toxins. LC-MS/MS analysis of 17 Alternaria toxins in urine and fecal samples allowed to gain first insights regarding xenobiotic metabolism and excretion rates. Alternariol (6-10%), alternariol monomethyl ether (AME, 6-7%) and tenuazonic acid (up to 55%) were recovered in urine and fecal samples (9%, 87%, 0.3%, respectively), while perylene quinones administered at comparatively high levels, were either determined at very low levels (up to 0.5% altertoxin I in urine and 15% in feces; 0.2% alterperylenol in urine and 3% in feces) or not at all (altertoxin II, stemphyltoxin III). AME-3-sulfate, which was not present in the administered extract, was determined in urine, representing up to 23% of the AME intake. Critical evaluation of the applied sample preparation protocol and LC-MS/MS analysis revealed interesting preliminary results and information crucial for improving follow-up experiments.

Topics: Alternaria; Animals; Benz(a)Anthracenes; Chromatography, Liquid; Feces; Lactones; Limit of Detection; Male; Mycotoxins; Perylene; Rats; Rats, Sprague-Dawley; Tandem Mass Spectrometry; Tenuazonic Acid

The group of the small-spored Alternaria species is particularly relevant in foods due to its high frequency and wide distribution in different crops. These species are responsible for the accumulation of mycotoxins and bioactive secondary metabolites in food. The taxonomy of the genus has been recently revised with particular attention on them; several morphospecies within this group cannot be segregated by phylogenetic methods, and the most recent classifications proposed to elevate several phylogenetic species-groups to the taxonomic status of section. The purpose of the present study was to compare the new taxonomic revisions in Alternaria with secondary metabolite profiles with special focus on sections Alternaria and Infectoriae and food safety. A total of 360 small-spored Alternaria isolates from Argentinean food crops (tomato fruit, pepper fruit, blueberry, apple, wheat grain, walnut, pear, and plum) was morphologically identified to species-group according to Simmons (2007), and their secondary metabolite profile was determined. The isolates belonged to A. infectoria sp.-grp. (19), A. tenuissima sp.-grp. (262), A. arborescens sp.-grp. (40), and A. alternata sp.-grp. (7); 32 isolates, presenting characteristics overlapping between the last three groups, were classified as Alternaria sp. A high chemical diversity was observed; 78 different metabolites were detected, 31 of them of known chemical structure. The isolates from A. infectoria sp.-grp. (=Alternaria section Infectoriae) presented a specific secondary metabolite profile, different from the other species-groups. Infectopyrones, novae-zelandins and phomapyrones were the most frequent metabolites produced by section Infectoriae. Altertoxin-I and alterperylenol were the only compounds that these isolates produced in common with members of section Alternaria. None of the well-known Alternaria toxins, considered relevant in foods, namely alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), tentoxin (TEN) or altenuene (ALT), were produced by isolates of this section. On the other hand, strains from section Alternaria (A. tenuissima, A. arborescens, and A. alternata sp.-grps.) shared a common metabolite profile, indistinguishable from each other. AOH, AME, ALT, TEN, and TeA were the most frequently mycotoxins produced, together with pyrenochaetic acid A and altechromone A. Alternaria section Alternaria represents a substantial risk in food, since their members in all types

Topics: Alternaria; Argentina; Blueberry Plants; Crops, Agricultural; Food Contamination; Food Microbiology; Fruit; Juglans; Lactones; Malus; Mycotoxins; Peptides, Cyclic; Phylogeny; Piper nigrum; Prunus domestica; Pyrus; Secondary Metabolism; Solanum lycopersicum; Tenuazonic Acid; Triticum

Alternaria spp. are major contaminants of wheat crops, causing both economic losses for producers and health risk for consumers due to the accumulation of toxic metabolites. The application of synthetic fungicides in the field may trigger mycotoxin accumulation, since fungistatic levels of those compounds might cause fungal responses to stress. Hence, new alternatives are needed for its control. The aim of this work was to compare the effects of a natural antifungal compound, the antifungal protein PgAFP, and a synthetic commercial one, on Alternaria tenuissima sp.-grp. growth, mycotoxin biosynthesis (tenuazonic acid and alternariols) and the expression of a stress-related gene associated with cell wall integrity (CWI) pathway, in a wheat-based medium at two water activities (a

Topics: Alternaria; Antifungal Agents; Cell Wall; Fungal Proteins; Fungicides, Industrial; Lactones; Mycotoxins; Penicillium chrysogenum; Tenuazonic Acid; Triticum; Water

Topics: Alternaria; Chromatography, Reverse-Phase; Food Analysis; Food Microbiology; Fruit; Lactones; Mycotoxins; Peptides, Cyclic; Solanum lycopersicum; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Tenuazonic Acid

Topics: Alternaria; Benz(a)Anthracenes; Chromatography, High Pressure Liquid; Food Contamination; Helianthus; Lactones; Mycotoxins; Seeds; South Africa; Tandem Mass Spectrometry; Tenuazonic Acid

To study the effects of water activity (a. Interacting conditions of a. The optimum and marginal conditions for growth and mycotoxin production by A. alternata on a SN media similar to grape composition were in agreement, but certain stressful conditions for growth evaluated also promote mycotoxin production.. Temperature and a

Topics: Alternaria; Argentina; Lactones; Mycotoxins; Temperature; Tenuazonic Acid; Vitis; Water; Wine

Alternaria arborescens has been reported as a common fungal species invading tomatoes and is capable of producing several mycotoxins in infected plants, fruits and in agricultural commodities. Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants of food. This species can produce these toxic metabolites together with AAL toxins (Alternaria alternata f. sp. lycopersicum toxins), which can act as inhibitors of sphingolipid biosynthesis. The objective of this study was to determine the effect of water activity (aw, 0.995, 0.975, 0.950) and temperature (6, 15, 20, 25 and 30 °C) on mycotoxin production by A. arborescens on a synthetic tomato medium. The optimum production of AOH and AME occurred at 0.975 aw after 40 days of incubation at 30 °C. The maximum TeA accumulation was observed at 0.975 aw and 25 °C and at 0.950 aw and 30 °C. AAL TA was produced in higher quantities at 0.995 aw and 30 °C. At 6 °C no quantifiable levels of AOH or AME were detected, but significant amounts of TeA were produced at 0.975 aw. In general, high aw levels and high temperatures were favorable for mycotoxin production. The greatest accumulation of all four toxins occurred at 0.975 aw and 30 °C. The results obtained here could be extrapolated to evaluate the risk of tomato fruits and tomato products contamination caused by these toxins.

Topics: Alternaria; Food Contamination; Food Microbiology; Fruit; Lactones; Mycotoxins; Solanum lycopersicum; Sphingolipids; Temperature; Tenuazonic Acid; Water

Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants in food materials. The objective of this study was to develop a pretreatment method with countercurrent chromatography (CCC) for enrichment and cleanup of trace Alternaria mycotoxins in food samples prior to high-performance liquid chromatography (HPLC) analysis. An Analytical CCC instrument with a column volume 22.5mL was used, and a two-phase solvent system composed of ethyl acetate and water modified with 6% [HOOMIM][Cl] in mass to volume ratio was selected. Under the optimized CCC operation conditions, trace amounts of AOH, AME, and TeA in large volume of liquid sample were efficiently extracted and enriched in the stationary phase, and then eluted out just by reversing the stationary phase as mobile phase in the opposite flowing direction tail-to-head. The enrichment and elution strategies are unique and can be fulfilled online with high enrichment factors (87-114) and high recoveries (81.14-110.94%). The method has been successively applied to the determination of Alternaria mycotoxins in real apple juice and wine samples with the limits of detection (LOD) in the range of 0.03-0.14μgL(-1). Totally 12 wine samples and 15 apple juice samples from the local market were analyzed. The detection rate of AOH and AME in both kinds of the samples were more than 50%, while TeA was found in relatively high level of 1.75-49.61μgL(-1) in some of the apple juice samples. The proposed method is simple, rapid, and sensitive and could also be used for the analysis and monitoring of Alternaria mycotoxin in other food samples.

Topics: Alternaria; Chromatography, High Pressure Liquid; Chromatography, Liquid; Countercurrent Distribution; Fruit and Vegetable Juices; Ionic Liquids; Lactones; Malus; Mycotoxins; Tenuazonic Acid; Wine

It is well known that the type and the availability of nitrogen have a great influence on the biosynthesis of certain mycotoxins. Here it is shown that some amino acids have no influence, some others strongly support and a third group inhibits the biosynthesis of ochratoxin (OTA) by Penicillium nordicum even in a complex medium, such as PDA. Arginine (Arg) is one of the strong OTA inhibiting amino acids. It was shown that Arg not only inhibits OTA in Penicillium but also citrinin (CIT) biosynthesis in Penicillium verrucosum, Penicillium expansum and Penicillium citrinum and alternariol (AOH), alternariol monomethylether (AME) and tenuazonic acid (TeA) biosynthesis in Alternaria alternata. The minimal inhibitory concentration of Arg differs depending on the mycotoxin and the species analysed. However, the OTA biosynthesis by P. verrucosum and P. nordicum was most sensitive. Growth, on the other hand, was much less affected by Arg. Urea, a metabolite of Arg catabolism, shows a similar inhibitory activity. In wheat medium containing 50mM Arg almost no OTA was produced by Penicillium, in contrast to plain wheat medium.

Topics: Alternaria; Arginine; Citrinin; Lactones; Mycotoxins; Ochratoxins; Penicillium; Tenuazonic Acid; Triticum; Urea

This study represents the first report about possibility of reduction of Alternaria toxins in wheat using the extrusion process. Effects of extrusion processing parameters - moisture content (w=16, 20, 24g/100g), feeding rate (q=15, 20, 25kg/h), and screw speed (v=300, 390, 480rpm), on reduction rate of tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME), in whole wheat flour were investigated. Temperature ranged between 111.1 and 160.8°C, while the absolute pressure was from 0.17 to 0.23MPa. The simultaneous influence of w and v was the most important for TeA reduction (p<0.05), while v and q were the most influential for AOH reduction (p<0.01). Level of AME reduction was mostly influenced by w and v (p<0.10). Optimal parameters for reduction of all three Alternaria toxins were as follows: w=24g/100g, q=25kg/h, v=390rpm, with a reduction of 65.6% for TeA, 87.9% for AOH and 94.5% for AME.

Topics: Alternaria; Flour; Food Contamination; Food Handling; Food Microbiology; Lactones; Mycotoxins; Pilot Projects; Principal Component Analysis; Reproducibility of Results; Tandem Mass Spectrometry; Temperature; Tenuazonic Acid; Triticum; Whole Grains

Although Fusarium species remain a main source of mycotoxin contamination of wheat, in recent years, due to the evident climatic changes, other mycotoxigenic fungi have been recognised as important wheat contaminants. Alternaria species, especially A. alternata, have been found as contaminants of wheat as well as wheat-based products. Under favourable conditions A. alternata very often produce alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and others Alternaria toxins. The aim of the present study was to examine the presence of three Alternaria toxins (AOH, AME and TeA) in wheat samples harvested during three years (2011-13). To this end, 92 samples were collected during wheat harvesting from different growing regions of the Autonomous Province of Vojvodina, which represents the most important wheat-growing area in Serbia. The presence of Alternaria toxins was analysed by HPLC with electrospray ionisation triple quadrupole mass spectrometry (LC-ESI-MS/MS). Among all the analysed wheat samples, 63 (68.5%) were contaminated with TeA, 11 (12.0%) with AOH and 6 (6.5%) with AME. Furthermore, the maximum and mean toxin concentrations were 2676 and 92.4 µg kg(-1), 48.9 and 18.6 µg kg(-1), and 70.2 and 39.0 µg kg(-1) for TeA, AOH and AME, respectively. Co-occurrence of three Alternaria toxins in wheat samples was detected in six samples; a combination of two toxins was found in two samples; and 64 samples contained one toxin. The results showed that among 92 analysed wheat samples, only 20 (21.7%) samples were without Alternaria toxins. The presence of Alternaria toxins was also investigated in terms of weather conditions recorded during the period of investigation, as well as with the sampling region. This study represents the first preliminary report of the natural occurrence of Alternaria toxins in wheat (Triticum aestivum) from Serbia.

Topics: Alternaria; Chromatography, High Pressure Liquid; Food Contamination; Lactones; Mycotoxins; Serbia; Tandem Mass Spectrometry; Tenuazonic Acid; Triticum

Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.

Topics: Alternaria; Brassica; Chromatography, High Pressure Liquid; Food Contamination; Food Microbiology; Lactones; Limit of Detection; Mycotoxins; Peptides, Cyclic; Tandem Mass Spectrometry; Tenuazonic Acid; Vegetables

A total of 181 wheat flour and 142 wheat-based foods including dried noodle, steamed bread and bread collected in China were analyzed for alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and tenuazonic acid (TeA) by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. TeA was the predominant toxin found in 99.4% wheat flour samples at levels ranging from 1.76 μg/kg to 520 μg/kg. TEN was another Alternaria toxin frequently detected in wheat flour samples (97.2%) at levels between 2.72 μg/kg and 129 μg/kg. AOH and AME were detected in 11 (6.1%) samples at levels ranging from 16.0 μg/kg to 98.7 μg/kg (AOH) and in 165 (91.2%) samples with a range between 0.320 μg/kg and 61.8 μg/kg (AME). AOH was quantified at higher levels than AME with the ratio of AOH/AME ranging from 1.0 to 3.7. Significant linear regressions of correlation in toxin concentrations were observed between AOH and AME, AME and TeA, TEN and TeA, AOH+AME and TeA. At an average and 95th percentile, dietary exposure to AOH and AME in the Chinese general population and different age subgroups exceeded the relevant threshold value of toxicological concern (TTC), with the highest exposure found in children which deserves human health concern. TEN and TeA seem unlikely to be health concerns for the Chinese via wheat-based products but attention should be paid to synergistic or additive effects of TeA with AOH, AME, TEN and a further assessment will be performed once more data on toxicity-guided fractionation of the four toxins are available. It is necessary to conduct a systemic surveillance of Alternaria toxins in raw and processed foods in order to provide the scientific basis for making regulations on these toxins in China.

Topics: Alternaria; China; Chromatography, High Pressure Liquid; Chromatography, Liquid; Food Contamination; Lactones; Mycotoxins; Tandem Mass Spectrometry; Tenuazonic Acid; Triticum

Alternaria spp. are known to form a spectrum of secondary metabolites with alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT) and tenuazonic acid (TA) as the major mycotoxins with respect to quantity. In the present study we investigated the contribution of these compounds for the DNA damaging properties of complex extracts of Alternaria spp. infested rice. Five different Alternaria strains were cultured on rice and analyzed for their production of AOH, AME, ALT and TA. The extracts of two strains with distinctly different toxin profiles were selected for further toxicological analysis. An extract from A. alternata DSM 1102 infested rice, found to contain predominantly TA, exhibited substantial DNA strand breaking properties in cultured human colon carcinoma cells in the comet assay, whereas TA as a single compound did not affect DNA integrity up to 200μM. An extract of A. alternata DSM 12633 infested rice, containing in comparable proportions AOH, AME and TA, exceeded by far the DNA damaging properties of the single compounds. In contrast to AOH, AME and TA, both selected extracts induced an increase of DNA modifications sensitive to the bacterial repair enzyme formamidopyrimidine DNA glycosylase (FPG) in the comet assay, indicative for oxidative DNA damage. Toxicity-guided fractionation of the DSM 12633 extract confirmed that these effects were not caused by AOH, AME or TA. Taken together, the mycotoxins AOH, AME and TA, representing the major mycotoxins with respect to quantity in A. alternata infested food, play only a subordinate role for the genotoxic properties of complex extracts and appear not to be involved in the induction of FPG sensitive sites.

Topics: Alternaria; Animals; Cell Cycle; Cell Line; Cricetinae; Dose-Response Relationship, Drug; Lactones; Molecular Structure; Mutagenicity Tests; Mutagens; Oryza; Tenuazonic Acid

Large amounts of tomato fruits and derived products are produced in Argentina and may be contaminated by Alternaria toxins. Limited information is available on the genetic variability, toxigenicity, and pathogenicity of Alternaria strains occurring on tomato. We analyzed 65 Alternaria strains isolated in Argentina from tomato fruits affected by black mould and from tomato puree, using amplified fragment length polymorphisms (AFLPs) technique. AFLP analysis resolved the set of strains in 3 main clusters (DICE similarity values of 58 and 60%) corresponding to A. alternata/tenuissima (44 strains), A. arborescens (15 strains) and to an unknown group (6 strains). Most of the representative strains, belonging to each AFLP cluster, when cultured on rice, produced tenuazonic acid (up to 46,760 mg/kg), alternariol monomethyl ether (AME, up to 1860 mg/kg), and alternariol (up to 70 mg/kg). The toxin profile related to the strains was not related to any AFLP cluster, except for AME which was produced at lower level by A. arborescens. Most of strains were pathogenic on two types of commonly cultivated tomato fruits. These findings provide new information on the variability within the Alternaria species complex associated with tomato disease.

Topics: Alternaria; Amplified Fragment Length Polymorphism Analysis; Argentina; DNA, Fungal; Fruit; Genetic Variation; Lactones; Mycotoxins; Plant Diseases; Sequence Analysis, DNA; Solanum lycopersicum; Tenuazonic Acid

The natural occurrence of Alternaria mycotoxins in Argentinean wheat from the zone 5 South during the 2004 to 2005 harvest was investigated in 64 wheat samples. All samples were highly contaminated with a wide range of fungal species. Alternaria was found as the main component of the mycota, with an infection percentage of 100%. Three mycotoxins produced by species of Alternaria were determined in wheat: alternariol, alternariol monomethyl ether, and tenuazonic acid. Alternariol was detected in 4 (6%) of 64 samples, with a range of 645 to 1,388 microg/kg (mean of 1,054 microg/kg); alternariol monomethyl ether, with a range of 566 to 7,451 microg/kg (mean of 2,118 microg/kg) in 15 (23%) of 64 samples; and tenuazonic acid in 12 (19%) of 64 samples, with a range of 1,001 to 8,814 microg/kg (mean, 2,313 microg/kg). Alternariol monomethyl ether was the predominant toxin, but tenuazonic acid was detected in higher concentrations. Alternariol was present in fewer samples and in lower levels than were the other toxins. Tenuazonic acid and alternariol monomethyl ether occurred together in four samples, while tenuazonic acid and alternariol co-occurred in one sample. This the first report of the natural occurrence of Alternaria mycotoxins in Argentinean wheat. Toxin levels were high, probably due to the heavy infection with Alternaria species found in the samples.

Topics: Alternaria; Argentina; Colony Count, Microbial; Consumer Product Safety; Food Contamination; Food Microbiology; Humans; Lactones; Mycotoxins; Prevalence; Species Specificity; Tenuazonic Acid; Triticum

Fungi contaminant of alpataco (Prosopis flexuosa) fruits from La Pampa province (Argentina) were identified. Alternaria alternata and Sphaeropsis sapinea were the dominant species. Phoma sp., Nigrospora sp., Preussia minima, Cladosporium sp., Pithomyces chartarum, Epicoccum nigrum, Aspergillus niger and Aspergillus speluneus were also isolated but with less frequency. Twelve strains of Alternaria alternata, the toxigenic species with higher incidence, were screened for alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) production. Since one isolate was able to produce AME, six isolates produced AOH and AME and two isolates produced AOH, AME and TA, these results indicate a potential risk of contamination with Alternaria toxins in this substrate.

Topics: Alternaria; Argentina; Food Contamination; Food Microbiology; Fruit; Fungi; Lactones; Mitosporic Fungi; Mycotoxins; Prosopis; Species Specificity; Tenuazonic Acid

The toxigenic potential of Alternaria strains isolated from Argentinean wheat was investigated. A total of 123 strains were assayed for the production of tenuazonic acid (TA), alternariol (AOH) and alternariol monomethyl ether (AME). All but one of the isolates were able to produce at least one of the three mycotoxins. TA was produced by 72% of the strains (1-14782 mg/kg), AOH by 87% (4-622 mg/kg) and AME by 91% (7-2625 mg/kg). The average level of TA detected for all strains (1757 mg/kg) was higher than the average level of both alternariols (162 mg/kg for AOH and 620 mg/kg for AME). TA was the toxin produced at the highest concentration but in lower frequency. Most of the strains were able to synthesize more than one toxin: 74 isolates (60%) were positive for all three toxins, 30 (24%) for both AOH and AME, 5 (4%) for both TA and AME, and 2 (2%) for TA and AOH. The widespread occurrence of Alternaria in wheat and its ability to produce mycotoxins suggests the possible occurrence of its toxins in wheat naturally infected with this fungus.

Topics: Alternaria; Argentina; Chromatography, High Pressure Liquid; Food Contamination; Food Microbiology; Lactones; Mycotoxins; Prevalence; Species Specificity; Tenuazonic Acid; Time Factors; Triticum

Some Alternaria species are able to produce plant pathogenic as well as toxic metabolites. In both agriculture and the food industry it is important know if toxigenic Alternaria are present to rapidly employ the correct corrective actions. The purpose of this work was to establish a real-time PCR method, which can detect and quantify apple pathogenic and toxigenic Alternaria. An AM-toxin I primer set, which could recognize Alternaria DNA only, was designed by using primers complementary to the AM-toxin I gene. The method could detect small amounts of DNA (4 pg) and still obtain a large dynamic range (4 decades) without interference from apple material. Eight Alternaria isolates were analyzed for the presence of AM-toxin I gene and their production of secondary metabolites. Then analyses showed that all eight isolates contained the AM toxin gene and were able to produce the plant pathogenic tentoxin in addition to AM toxin I. The analyses also showed the production of tenuazonic acid, alternariols, Altenuene, altenusin and/or altertoxin I in pure culture. Analyses of inoculated apples showed that both the AM-toxin gene and alternariol monomethyl ether could be detected. Morphological analyses suggested that the eight Alternaria strains, though they all carried the AM toxin genes, probably belong to different but closely related un-described Alternaria taxa in the A. tenuissima species-group based on morphological and chemical differences.

Topics: Alternaria; Chromatography, High Pressure Liquid; Lactones; Malus; Mycotoxins; Polymerase Chain Reaction; Sensitivity and Specificity; Tenuazonic Acid

Molds of the genus Alternaria are common food pathogens responsible for the spoilage of fruits, vegetables, grains, and nuts. Although consumption of Alternaria alternata-contaminated foodstuffs has been implicated in an elevated incidence of esophageal carcinogenesis, the mutagenic potencies of several A. alternata toxins seem unable to account for the levels of activity found using crude mycelial extracts. In this study, the mutagenic effects of nitrosylation were examined with the major Alternaria metabolites Altenuene (ALT), Alternariol (AOH), Alternariol Monomethyl Ether (AME), Altertoxin I (ATX I), Tentoxin (TENT), Tenuazonic Acid (TA), and Radicinin (RAD) using the Ames Salmonella strains TA98 and TA100. In the absence of nitrosylation, ATX I was mutagenic when tested from 1 to 100 microg/plate in TA98 with rat liver S9 for activation, while AOH and ATX I were weakly mutagenic +/- S9 in TA100. Incubation with nitrite generally increased mutagenic potencies with ATX I strongly mutagenic +/- S9 in both TA98 and TA100, while ALT, AOH, AME, and RAD responses were enhanced in TA100 + S9. However, subsequent examination of three extracts made from A. alternata culture broth, acetone-washed mycelia, and the acetone washes showed a different mutagenic response with both broth and acetone washes directly mutagenic in TA98 and TA100 but with a reduced response + S9. The acetone-washed mycelial extract was found to have the lowest mutagenic activity of the three extracts tested. Nitrosylation had little effect on the mutagenicity of any of the extracts. Thus, while nitrosylation increases the mutagenicity of ATX I, and to a lesser extent that of several other Alternaria toxins, the results demonstrate that Alternaria produces a major mutagenic activity with a S. typhimurium response different from that found with the purified toxins. Efforts are currently underway to chemically identify this mutagenic species. Published 2001 Wiley-Liss, Inc.

Topics: Alternaria; Animals; Benz(a)Anthracenes; Dose-Response Relationship, Drug; Hydrogen-Ion Concentration; Lactones; Microsomes, Liver; Models, Chemical; Mutagenicity Tests; Mutagens; Peptides, Cyclic; Perylene; Pyrones; Rats; Salmonella typhimurium; Sodium Nitrite; Tenuazonic Acid

Alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TEA) are secondary metabolites of Alternaria species. Cyclopiazonic acid (CPA) is produced by fungi belonging to the ubiquitous genera of Penicillium and Aspergillus and has been found in a wide range of foods. These toxins were searched for by liquid chromatography with diode-array detection in tomato products processed and sold in Brazil. Eighty samples of tomato products were examined (juice 11, pulp 22, purée 22, paste 24 and whole stewed tomato 1). Eleven brands sold nationwide were covered. TEA was found in seven samples of tomato pulp (39-111 ng/g) and four samples of tomato puree (29-76 ng/g). CPA was found in six samples of pulp (64-178 ng/g) and two samples of purée (36-117 ng/g). Co-occurrence of TEA and CPA was found in two samples of purée and one of pulp. This is the first time that the presence of CPA has been reported in tomato products. Neither AME nor AOH were detected in the samples.

Topics: Alternaria; Brazil; Chromatography, High Pressure Liquid; Humans; Indoles; Lactones; Mycotoxins; Solanum lycopersicum; Tenuazonic Acid

Sunflower (Heliantus annuus) is an important crop in the economy of Argentina due to its high production and demand from domestic and export markets. The aim of this study was to evaluate the presence of Alternaria species and its mycotoxins in ensiled sunflower seeds. The sampling was carried out in three periods: at the beginning of ensiling, on the second month and finally on the fourth month. The mycological analysis was made with disinfected seeds, cultured on Dichloran-Rose Bengal-Chloramphenicol (DRBC) and Dichloran-Chloramphenicol-Malt Extract-Agar (DCMA). The toxins were analyzed by thin layer chromatography (TLC). A alternata was the main fungal species isolated. The incidence of Alternaria species and the levels of alternariol and tenuazonic acid decreased as the time of ensiling increased. Alternariol monomethyl ether was detected in two samples from the second and third sampling periods.

Topics: Alternaria; Chromatography, Thin Layer; Helianthus; Lactones; Mycotoxins; Seeds; Silage; Tenuazonic Acid; Time Factors

Analytical methods are described for detection of the Alternaria mycotoxins alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT) and tenuazonic acid (TeA) in natural and semisynthetic laboratory cultures. After extraction and purification of the crude extract by column chromatography on silica gel the qualitative and quantitative analyses were carried out by thin layer (TLC)- and high performance liquid chromatography (HPLC). HPLC separations were achieved using a Hypersil ODS column with methanol/water containing a complexing agent as eluent. Detection at 340 nm (AOH, AME, ALT) and 280 nm (TeA), respectively, has proved to be favourably. AME and TeA were produced in high purity and high yields as standard substances by two Alternaria strains. The identity of the toxins could be confirmed by EI-, CI- and FAB-mass spectrometry.

Topics: Alternaria; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Lactones; Mass Spectrometry; Molecular Structure; Mycotoxins; Spectrometry, Mass, Fast Atom Bombardment; Tenuazonic Acid

The ability to produce the Alternaria mycotoxins alternariol (AOH), alternariol monomethyl ether (AME) and altenuene (ALT) were studied on 87 Alternaria strains. 50 isolates were studied to produce tenuazonic acid (TeA). The strains were isolated from CCM-maize and stored hay. They were cultured under optimum conditions and analysed by various chromatographic methods for the 4 mycotoxins. All Alternaria strains studied produced AME and TeA, 77 per cent also AOH. A production of ALT was detected only in 18 per cent of the isolates. The concentrations of toxins produced were 0.08-482 (162) ppm for AME, 0.05-1862 (121) ppm for AOH, 0.1-34 (9.1) ppm for ALT and 0.02-42 (11.3) mg/100 ml liquid medium for TeA. The species Alternaria alternata (Fries) Keissler and Alternaria tenuissima (Kunze:Fr.) Wiltshire produced the greatest amounts of all mycotoxins studied.

Topics: Alternaria; Lactones; Mycotoxins; Poaceae; Tenuazonic Acid; Zea mays

Alternaria alternata strain 8442-3 was inoculated into tomatoes (Lycopersicon esculentum Mill.) and Red Delicious cultivar apples (Malus domestica Borkh.). Half of the lots of each fruit were shrink-wrapped in high-density polyethylene film. Wrapped and unwrapped fruits were incubated under darkness at 4, 15 and 25 degrees C for up to 5 weeks. A high-performance liquid chromatography method was developed to quantitate tenuazonic acid (TeA), alternariol (AOH), alternariol methyl ether (AME), and altenuene (ALT). Shrink-wrapping retarded, but did not completely inhibit growth in tomatoes for 3-7 days. Concentrations of up to 120.6 mg of AOH and 63.7 mg of AME per 100 g of tissue were produced in unwrapped tomatoes stored at 15 degrees C for 4 weeks; 19.0 mg of ALT per 100 g of tomato tissue was produced after 3 weeks at 25 degrees C. AOH, AME and ALT were also produced in unwrapped tomatoes stored at 4 degrees C; however, no TeA was detected in decayed tomatoes, regardless of type of wrapping or storage temperature. Shrink-wrapping resulted in decreased production of AOH, AME, and ALT. Alternaria toxins were not detected in apples stored at 4 and 15 degrees C. The highest concentration of AOH produced (48.8 mg per 100 g of tissue) was in unwrapped apples stored at 25 degrees C for 2 weeks; 12.3 mg per 100 g of tissue of shrink-wrapped apples was detected after 5 weeks of storage at 25 degrees C, while ALT reached 5.7 mg per 100 g after 4 weeks. TeA was not detected in apples infected with A. alternata.

Topics: Alternaria; Chromatography, High Pressure Liquid; Food Microbiology; Food Preservation; Fruit; Lactones; Mycotoxins; Solvents; Temperature; Tenuazonic Acid

Both water activity (aW) and temperature affected the production of altenuene (AE), alternariol (AOH), and alternariol monomethyl ether (AME) by Alternaria alternata on wheat extract agar and wheat grain. Greatest production of all three mycotoxins occurred at 0.98 aW and 25 degrees C on both substrates. At 0.98 aW and 25 degrees C, a single colony of A. alternata grown on wheat extract agar produced 807 micrograms of AOH, 603 micrograms of AME, and 169 micrograms of AE ml in 30 days. However, production of all three mycotoxins at 0.95 aW was less than 40% of these amounts. Little toxin was produced at 0.90 aW. Changing temperature and aW altered the relative amounts of the different toxins produced on agar. At 15 degrees C and 0.98 aW, maxima of 52 micrograms of AOH and 25 micrograms of AME per ml were produced after 15 and 30 days, respectively, whereas AE continued to increase and reached 57 micrograms/ml after 40 days. At 15 degrees C and 0.95 aW, production was, respectively, 62, 10, and 5 micrograms/ml after 40 days. All three metabolites were produced at 5 degrees C and 0.98 to 0.95 aW and at 30 degrees C and 0.98 to 0.90 aW. On wheat grain at 25 degrees C and 0.98 to 0.95 aW, more AME was produced than AOH or AE, but at 15 degrees C there was less AME than AOH or AE. Only trace amounts of AE, AOH, and AME were found at 15 to 25 degrees C and 0.90 aW, but production of AME was inhibited at 30 degrees C and 0.95 aW or less.

Topics: Alternaria; Aspergillus; Culture Media; Lactones; Mitosporic Fungi; Mycotoxins; Penicillium; Plant Extracts; Temperature; Tenuazonic Acid; Time Factors; Triticum; Water

The effects in the chicken embryo assay of four Alternaria metabolites (alternariol [AOH], alternariol methyl ether [AME], altenuene [ALT], and tenuazonic acid [TA]) were investigated. Administered to 7-day-old chicken embryos by yolk sac injection, AOH, AME, and ALT caused no mortality or teratogenic effect at doses up to 1,000, 500, and 1,000 micrograms per egg, respectively. TA exhibited a calculated 50% lethal dose of 548 micrograms per egg, with no teratogenic effect observed at either lethal or sublethal doses.

Topics: Alternaria; Animals; Antibiotics, Antineoplastic; Chick Embryo; Food Contamination; Lactones; Lethal Dose 50; Mitosporic Fungi; Tenuazonic Acid