alternariol and altenuene

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

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

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

Topics: Alternaria; Beijing; Chromatography, High Pressure Liquid; Chromatography, Liquid; Drinking Water; Lactones; Limit of Detection; Mycotoxins; Solid Phase Extraction; Tandem Mass Spectrometry; Water Pollutants

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

A new secondary metabolite, 2-O-methylalternariol 4-O-β-[4-methoxyl-glucopyranoside] (1), together with four known compounds alternariol methyl ether (2), altenuene (3), isoaltenuene (4) and 2-(2'S-hydroxypropyl)-5-methyl-7-hydroxychromone (5), was isolated from the fungus Alternaria alternate cib-137. Its structure was elucidated on the basis of spectroscopic data. Compounds 3 and 4 demonstrated moderate activity against Staphylococcus aureus.

Topics: Alternaria; Anti-Bacterial Agents; Glucosides; Lactones; Molecular Structure; Staphylococcus aureus

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

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method was developed for the determination of altenuene (ALT), alternariol (AOH), tentoxin and alternariol monomethyl ether (AME) in apple juice concentrate (AJC). The sample was diluted with water, and then cleaned up with a PS DVB column. The quantification was carried out using an external standard method. The UPLC was performed on a BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using a gradient elution of acetonitrile and water. The MS/MS was performed with multiple reaction monitoring (MRM) mode. The limits of quantification of the four Alternaria toxins were between 1.0 and 5.0 microg/L. The recoveries were 77.8%-117.2% with the relative standard deviations less than 9.7%. The method is sensitive, stable and reliable. It's suitable for the quantitative and qualitative analyses of the four Alternaria toxins in AJC.

Topics: Alternaria; Beverages; Chromatography, High Pressure Liquid; Food Contamination; Lactones; Malus; Mycotoxins; Peptides, Cyclic; Tandem Mass Spectrometry

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

The production of mycotoxins by Alternaria alternata in cellulosic ceiling tiles was examined with thin-layer chromatography and high-performance liquid chromatography procedures. Alternariol and alternariol monomethyl ether were found in ceiling tile extracts, whereas extracts of control rice cultures of all three isolates produced these mycotoxins plus altenuene and altertoxin I. Extensive fungal growth and mycotoxin production occurred in the ceiling tiles at relative humidities of 84-89% and 97%.

Topics: Air Microbiology; Alternaria; Benz(a)Anthracenes; Cellulose; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Lactones; Mutagens; Mycotoxins; Perylene; Sick Building Syndrome

Heptafluorobutyrate (HFB) derivatives have not previously been used for GC of Alternaria mycotoxins. Capillary (0.5 micron film) GC-mass spectrometry (MS) showed that full and partial derivatives of alternariol (AOH), alternariol monomethyl ether (AME) and altenuene (ALT); a structurally uncharacterized derivative of altertoxin I (ALTX-I); and a tris-HFB derivative of tenuazonic acid (TA) were formed with heptafluorobutyric anhydride and a basic catalyst. Full and partial trimethylsilyl (TMS) ethers of these mycotoxins were formed with Tri-Sil TBT. Apple juice extracts caused increased response in GC-MS of AOH bis-HFB and bis-TMS derivatives. Natural occurrence of AOH in apple juice has been demonstrated.

Topics: Alternaria; Benz(a)Anthracenes; Beverages; Cholinesterase Inhibitors; Chromatography, High Pressure Liquid; Fluorocarbons; Fruit; Gas Chromatography-Mass Spectrometry; Lactones; Mycotoxins; Perylene

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