Search Results (4)

Alternaria mycotoxins represent a significant and emerging concern in the field of food safety due to their widespread occurrence in diverse food and feed commodities, including cereals, tomatoes, oilseeds, and dried fruits. Among these, alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and altertoxin-I (ATX-I) are the most frequently detected, often co-occurring at varying concentrations, thereby increasing the complexity of exposure and risk assessment. The gastrointestinal tract (GIT) is a crucial target of these toxins, as well as the liver, particularly considering its detoxifying role. Nevertheless, despite being a source of possible gastrointestinal and hepatic toxicity, there is still scarce data on the toxicokinetics of Alternaria toxins, on their mode of action, and respective toxic effects. To date, in vitro studies have shown that different Alternaria mycotoxins exhibit diverse toxicological effects, which may be dependent on their chemical structure. AOH and ATX-I have shown genotoxicity and cytotoxicity, mainly through interaction with the DNA and apoptosis, respectively. Tentoxin (TEN) has displayed hepatotoxic potential via impairment of detoxification pathways, and altenuene (ALT) has revealed lower toxicity. In vivo, AME and ATX-II revealed genotoxicity, while AOH and ATX-I showed context-dependent variability in their effects. Altogether, this review emphasizes that there is still a great lack of knowledge on these mycotoxins and an urgent need for more comprehensive toxicological and occurrence data to support proper risk assessment and, ultimately, regulatory decision-making. Full article

Alternaria fungi are widely distributed plant pathogens that invade crop products, causing significant economic damage. In addition, toxic secondary metabolites produced by the fungi can also endanger consumers. Many of these secondary metabolites are chemically characterized as mycotoxins. In this study, Q Exactive Orbitrap mass spectrometry was used for the non-targeted analysis of the metabolome of seven Alternaria isolates cultured on Potato Carrot Agar (PCA), Potato Dextrose Agar (PDA) and Potato Sucrose Agar (PSA) medium. Due to the difficulty of detecting modified toxins, an analytical strategy with multiple visual analysis tools was also used to determine the presence of sulfate conjugated toxins, as well as to visualize the molecular network of Alternaria toxins. The results show that PSA medium exhibits more advantageous properties for the culture of Alternaria, with more toxigenic species and quantities and more obvious metabolic pathways. Based on high-resolution tandem mass spectrometry (MS/MS) data, the mycotoxins and their metabolites were mainly clustered into four groups: alternariol (AOH)/alternariol monomethyl ether (AME)/altenusin (ALU)/altenuene (ALT)/dehydroaltenusin (DHA)/Desmethyldehydroaltenusin (DMDA) families, Altertoxin-I (ATX-I) family, tentoxin (TEN) family and tenuazonic acid (TeA) family. Moreover, the PSA medium is more suitable for the accumulation of AOH, AME, ALU, ALT, DHA and DMDA, while the PDA medium is more suitable for the accumulation of ATX-I, TEN and TeA. This research may provide theoretical support for the metabolomics study of Alternaria. Full article

The potato is a crop of global importance for the food industry. This is why effective protection against pathogens is so important. Fungi as potato pathogens are responsible for plant diseases and a significant reduction in yields, as well as for the formation of mycotoxins. This study focuses on the effect of three natural biocides, yeast Metschnikowia pulcherrima, lactic acid bacteria Lactiplantibacillus plantarum, and aqueous garlic extract, on the improvement of the physiology of planted potato tubers and the reduction in mycotoxin formation. The secondary metabolites produced by the fungal pathogens of genera Fusarium, Alternaria, Colletotrichum, Rhizoctonia, and Phoma in the presence of these biocontrol agents were compared to profiles obtained from contaminated potatoes. Analysis of liquid chromatography coupled with tandem mass spectrometry data showed the presence of 68 secondary metabolites, including the mycotoxins: alternariol, alternariol methyl ether, altertoxin-I, aurofusarin, beauvericin, diacetoxyscirpenol, enniatin B, and sterigmatocystin. The studies showed that the applied biocontrol agents had a positive effect on the physiological parameters of potatoes (including root growth, stem growth, gas exchange, and chlorophyll content index) and on the reduction in the production of mycotoxins and other secondary metabolites by Fusarium, Alternaria, and Phoma. Full article

Alternaria mycotoxins including alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), altertoxin-I (ATX-I), tentoxin (TEN), and tenuazonic acid (TeA), are ubiquitous contaminants in agricultural products. A method for the simultaneous determination of these six toxins by ultrahigh performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) with solid phase extraction (SPE) was validated in rice, sesame, tomato, and apple juice matrices. The performance of the method was evaluated in terms of linearity (R² > 0.999), the limit of detection (0.04–1.67 μg/kg), the limit of quantification (0.12–5.06 μg/kg), recovery (80.0–114.7%), and precision (<17.7%). The validated method was applied to monitor 152 marketed food samples in South Korea, as well as to investigate the co-occurrence and correlation between Alternaria toxins. The mean occurrence levels were 2.77 μg/kg for AOH, 4.36 μg/kg for AME, 0.14 μg/kg for ALT, 0.11 μg/kg for ATX-I, 0.43 μg/kg for TEN, and 104.56 μg/kg for TeA. Mean and extreme (95th percentile) daily dietary exposures of South Koreans to Alternaria toxins were estimated to be 22.93 ng/kg b.w./day and 86.07 ng/kg b.w./day, respectively. Full article