Names | |
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IUPAC name 3α,7α,15-Trihydroxy-12,13-epoxytrichothec-9-en-8-one | |
Systematic IUPAC name (2R,2′S,3R,5R,5aR,6S,9aR)-3,8-Dihydroxy-5a-(hydroxymethyl)-5,6-dimethylspiro[[2,5]methano[1]benzoxepine-10,2′-oxiran]-7(6H)-one | |
Other names Deoxynivalenol (DON) Vomitoxin | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.129.971 |
KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C15H20O6 | |
Molar mass | 296.319 g·mol−1 |
Related compounds | |
Related compounds | nivalenol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Vomitoxin, also known as deoxynivalenol (DON), is a type B trichothecene, an epoxy-sesquiterpenoid. This mycotoxin occurs predominantly in grains such as wheat, barley, oats, rye, and corn, and less often in rice, sorghum, and triticale. The occurrence of deoxynivalenol is associated primarily with Fusarium graminearum (Gibberella zeae) and F. culmorum , both of which are important plant pathogens which cause fusarium head blight in wheat and gibberella or fusarium ear blight in corn. The incidence of fusarium head blight is strongly associated with moisture at the time of flowering (anthesis), and the timing of rainfall, rather than the amount, is the most critical factor. However, increased amount of moisture towards harvest time has been associated with lower amount of vomitoxin in wheat grain due to leaching of toxins. [1] Furthermore, deoxynivalenol contents are significantly affected by the susceptibility of cultivars towards Fusarium species, previous crop, tillage practices, and fungicide use. [2] It occurs abundantly in grains in Norway due to heavy rainfall. [3]
F. graminearum grows optimally at a temperature of 25 °C and at a water activity above 0.88. F. culmorum grows optimally at 21 °C and at a water activity above 0.87. The geographical distribution of the two species appears to be related to temperature, F. graminearum being the more common species occurring in warmer climates. Deoxynivalenol has been implicated in incidents of mycotoxicoses in both humans and farm animals.
Vomitoxin belongs to a class of mycotoxins (trichothecenes) which are strong inhibitors of protein synthesis; [4] exposure to vomitoxin causes the brain to decrease its uptake of the amino acid tryptophan and, in turn, its synthesis of serotonin. Reduced levels of serotonin are believed to be responsible for the anorexic effects of DON and other trichothecenes. Irritation of the gastrointestinal tract may also play a role in reducing food intake, and may also partially explain the high incidence of paraesophageal stomach ulcers observed in sows during food refusal. In humans DON is extensively glucuronidated and excreted via urine. [5]
When compared to other trichothecene mycotoxins which can form in grains and forages, vomitoxin is relatively mild. Reduced feed intake, with its accompanying decrease in performance, is the only symptom of vomitoxin toxicity livestock producers will likely encounter. This response to vomitoxin appears to occur through the central nervous system.
A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize. Edible grains from other plant families, such as buckwheat and quinoa, are pseudocereals. Most cereals are annuals, producing one crop from each planting, though rice is sometimes grown as a perennial. Winter varieties are hardy enough to be planted in the autumn, becoming dormant in the winter, and harvested in spring or early summer; spring varieties are planted in spring and harvested in late summer. The term cereal is derived from the name of the Roman goddess of grain crops and fertility, Ceres.
Mold health issues refer to the harmful health effects of molds and their mycotoxins. However, recent research has shown these adverse health effects are caused not exclusively by molds, but also other microbial agents and biotoxins associated with dampness, mold, and water-damaged buildings, such as gram-negative bacteria that produce endotoxins, as well as actinomycetes and their associated exotoxins. Approximately 47% of houses in the United States have substantial levels of mold, with over 85% of commercial and office buildings found to have water damage predictive of mold. As many as 21% of asthma cases may result from exposure to mold. Substantial and statistically significant increases in the risks of both respiratory infections and bronchitis have been associated with dampness in homes and the resulting mold.
Fusarium ear blight (FEB), is a fungal disease of cereals, including wheat, barley, oats, rye and triticale. FEB is caused by a range of Fusarium fungi, which infects the heads of the crop, reducing grain yield. The disease is often associated with contamination by mycotoxins produced by the fungi already when the crop is growing in the field. The disease can cause severe economic losses as mycotoxin-contaminated grain cannot be sold for food or feed.
Aflatoxins are various poisonous carcinogens and mutagens that are produced by certain molds, particularly Aspergillus species mainly by Aspergillus flavus and Aspergillus parasiticus. According to the USDA, "They are probably the best known and most intensively researched mycotoxins in the world." The fungi grow in soil, decaying vegetation and various staple foodstuffs and commodities such as hay, maize, peanuts, coffee, wheat, millet, sorghum, cassava, rice, chili peppers, cottonseed, tree nuts, sesame seeds, sunflower seeds, and various cereal grains and oil seeds. In short, the relevant fungi grow on almost any crop or food. When such contaminated food is processed or consumed, the aflatoxins enter the general food supply. They have been found in both pet and human foods, as well as in feedstocks for agricultural animals. Animals fed contaminated food can pass aflatoxin transformation products into milk, milk products, and meat. For example, contaminated poultry feed is the suspected source of aflatoxin-contaminated chicken meat and eggs in Pakistan.
A mycotoxin is a toxic secondary metabolite produced by fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' is usually reserved for the toxic chemical products produced by fungi that readily colonize crops.
Fusarium is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the soil microbial community. Some species produce mycotoxins in cereal crops that can affect human and animal health if they enter the food chain. The main toxins produced by these Fusarium species are fumonisins and trichothecenes. Despite most species apparently being harmless, some Fusarium species and subspecific groups are among the most important fungal pathogens of plants and animals.
T-2 mycotoxin is a trichothecene mycotoxin. It is a naturally occurring mold byproduct of Fusarium spp. fungus which is toxic to humans and other animals. The clinical condition it causes is alimentary toxic aleukia and a host of symptoms related to organs as diverse as the skin, airway, and stomach. Ingestion may come from consumption of moldy whole grains. T-2 can be absorbed through human skin. Although no significant systemic effects are expected after dermal contact in normal agricultural or residential environments, local skin effects can not be excluded. Hence, skin contact with T-2 should be limited.
Fumonisin B1 is the most prevalent member of a family of toxins, known as fumonisins, produced by multiple species of Fusarium molds, such as Fusarium verticillioides, which occur mainly in maize (corn), wheat and other cereals. Fumonisin B1 contamination of maize has been reported worldwide at mg/kg levels. Human exposure occurs at levels of micrograms to milligrams per day and is greatest in regions where maize products are the dietary staple.
Yellow rain was a 1981 political incident in which the United States Secretary of State Alexander Haig accused the Soviet Union of supplying T-2 mycotoxin to the communist states in Vietnam, Laos and Cambodia for use in counterinsurgency warfare. Refugees described many different forms of "attacks", including a sticky yellow liquid falling from planes or helicopters, which was dubbed "yellow rain". The U.S. government alleged that over ten thousand people had been killed in attacks using these supposed chemical weapons. The Soviets denied these claims and an initial United Nations investigation was inconclusive.
The trichothecenes are a large family of chemically related mycotoxins. They are produced by various species of Fusarium, Myrothecium, Trichoderma/Podostroma, Trichothecium, Cephalosporium, Verticimonosporium, and Stachybotrys. Chemically, trichothecenes are a class of sesquiterpenes.
Zearalenone (ZEN), also known as RAL and F-2 mycotoxin, is a potent estrogenic metabolite produced by some Fusarium and Gibberella species. Specifically, the Gibberella zeae, the fungal species where zearalenone was initially detected, in its asexual/anamorph stage is known as Fusarium graminearum. Several Fusarium species produce toxic substances of considerable concern to livestock and poultry producers, namely deoxynivalenol, T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS) and zearalenone. Particularly, ZEN is produced by Fusarium graminearum, Fusarium culmorum, Fusarium cerealis, Fusarium equiseti, Fusarium verticillioides, and Fusarium incarnatum. Zearalenone is the primary toxin that binds to estrogen receptors, causing infertility, abortion or other breeding problems, especially in swine. Often, ZEN is detected together with deoxynivalenol in contaminated samples and its toxicity needs to be considered in combination with the presence of other toxins.
Beauvericin is a depsipeptide with antibiotic and insecticidal effects belonging to the enniatin family. It was isolated from the fungus Beauveria bassiana, but is also produced by several other fungi, including several Fusarium species; it may therefore occur in grain contaminated with these fungi. Beauvericin is active against Gram-positive bacteria and mycobacteria, and is also capable of inducing programmed cell death in mammals.
Mycotoxicology is the branch of mycology that focuses on analyzing and studying the toxins produced by fungi, known as mycotoxins. In the food industry it is important to adopt measures that keep mycotoxin levels as low as practicable, especially those that are heat-stable. These chemical compounds are the result of secondary metabolism initiated in response to specific developmental or environmental signals. This includes biological stress from the environment, such as lower nutrients or competition for those available. Under this secondary path the fungus produces a wide array of compounds in order to gain some level of advantage, such as incrementing the efficiency of metabolic processes to gain more energy from less food, or attacking other microorganisms and being able to use their remains as a food source.
Fusarium culmorum is a fungal plant pathogen and the causal agent of seedling blight, foot rot, ear blight, stalk rot, common root rot and other diseases of cereals, grasses, and a wide variety of monocots and dicots. In coastal dunegrass, F. culmorum is a nonpathogenic symbiont conferring both salt and drought tolerance to the plant.
Gibberella zeae, also known by the name of its anamorph Fusarium graminearum, is a fungal plant pathogen which causes fusarium head blight (FHB), a devastating disease on wheat and barley. The pathogen is responsible for billions of dollars in economic losses worldwide each year. Infection causes shifts in the amino acid composition of wheat, resulting in shriveled kernels and contaminating the remaining grain with mycotoxins, mainly deoxynivalenol (DON), which inhibits protein biosynthesis; and zearalenone, an estrogenic mycotoxin. These toxins cause vomiting, liver damage, and reproductive defects in livestock, and are harmful to humans through contaminated food. Despite great efforts to find resistance genes against F. graminearum, no completely resistant variety is currently available. Research on the biology of F. graminearum is directed towards gaining insight into more details about the infection process and reveal weak spots in the life cycle of this pathogen to develop fungicides that can protect wheat from scab infection.
Crown rot of wheat is caused by the fungal pathogen Fusarium pseudograminearum. F. pseudograminearum is a member of the fungal phylum Ascomycota and is also known as Gibberella coronicola (teleomorph). It is a monoecious fungus, meaning it does not require another host other than wheat to complete its life cycle. Although F. pseudograminearum can produce both anamorphic and teleomorphic states, the teleomorph is usually not present for crown rot of wheat. This Fusarium species has, until recently, been considered to be the same as the species known as Fusarium graminearum due to many similar characteristics. One of the only differences between the two species is that F. pseudograminearum lacks its sexual stage on the wheat host.
Fusarium sporotrichioides is a fungal plant pathogen, one of various Fusarium species responsible for damaging crops, in particular causing a condition known as Fusarium head blight in wheat, consequently being of notable agricultural and economic importance. The species is ecologically widespread, being found across tropical and temperate regions, and is a significant producer of mycotoxins, particularly trichothecenes. Although mainly infecting crops, F. sporotrichioides-derived mycotoxins can have repercussions for human health in the case of the ingestion of infected cereals. One such example includes the outbreak of alimentary toxic aleukia (ATA) in Russia, of which F. sporotrichioides-infected crop was suspected to be the cause. Although current studies on F. sporotrichioides are somewhat limited in comparison to other species in the genus, Fusarium sporotrichioides has found several applications as a model system for experimentation in molecular biology.
Mycoestrogens are xenoestrogens produced by fungi. They are sometimes referred to as mycotoxins. Among important mycoestrogens are zearalenone, zearalenol and zearalanol. Although all of these can be produced by various Fusarium species, zearalenol and zearalanol may also be produced endogenously in ruminants that have ingested zearalenone. Alpha-zearalanol is also produced semisynthetically, for veterinary use; such use is prohibited in the European Union.
Nivalenol (NIV) is a mycotoxin of the trichothecene group. In nature it is mainly found in fungi of the Fusarium species. The Fusarium species belongs to the most prevalent mycotoxin producing fungi in the temperate regions of the northern hemisphere, therefore making them a considerable risk for the food crop production industry.
Stenocarpella maydis (Berk.) Sutton is a plant pathogenic fungus and causal organism of diplodia ear and stalk rot. Corn and canes are the only known hosts to date. No teleomorph of the fungus is known.
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