Names | |
---|---|
IUPAC name (11S)-8,12-Dioxo-1β,2β:7,11-diepoxy-7α-eremophil-9-en-3β-yl acetate | |
Systematic IUPAC name (1aR,2R,2′R,3R,3′S,3aR,7bS)-3′-Formyl-3,3′,3a-trimethyl-6-oxo-1a,2,3a,4,6,7b-hexahydro-3H-spiro[naphtho[1,2-b]oxirene-5,2′-oxiran]-2-yl acetate | |
Identifiers | |
3D model (JSmol) | |
3DMet | |
ChEBI | |
ChEMBL | |
ChemSpider | |
KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Penicillin Roquefort toxin (PR toxin) is a mycotoxin produced by the fungus Penicillium roqueforti . In 1973, PR toxin was first partially characterized by isolating moldy corn on which the fungi had grown. [1] Although its lethal dose was determined shortly after the isolation of the chemical, details of its toxic effects were not fully clarified until 1982 in a study with mice, rats, anesthetized cats and preparations of isolated rat auricles. [2]
PR toxin contains multiple functional groups, including acetoxy (CH3COO-), aldehyde (-CHO), α,β-unsaturated ketone (-C=C-CO) and two epoxides. [3] The aldehyde group on C-12 is directly involved in the biological activity as removal leads to inactivation of the compound. The two epoxide groups do not play an important role, as removal showed no difference in activity. When exposed to air, PR toxin may decompose. How and why this happens, is however not known. [4]
PR toxin is derived from the 15-carbon hydrocarbon aristolochene, a sesquiterpene produced from farnesyl diphosphate catalyzed by the enzyme aristolochene synthase. Aristolochene then gains an alcohol, a ketone, and an additional alkene, mediated by hydroxysterol oxidase and quinone oxidoreductase.[ clarification needed ] Addition of the fused-epoxide oxygen by P450 monooxygenase gives eremofortin B. Epoxidation of the isopropenyl sidechain, again by P450 monooxygenase, and addition of the acetyl group by an acetyltransferase gives eremofortin A. A short-chain oxidoreductase oxidizes a methyl group on the side-chain to eremofortin C, the primary alcohol analog of PR toxin (incorrectly illustrated in the following diagram), which is then further oxidized by a short-chain alcohol dehydrogenase to give the aldehyde. [3]
Eremofortin C has been isolated from microbial sources and found to be in a spontaneous equilibrium between an open-chain hydroxy–ketone structure and a lactol form. [5]
Different experiments have shown the effects of the PR toxin on liver cells in culture (in vitro) and in the liver (in vivo). [4] [6] [7]
The PR toxin caused an inhibition of the incorporation of amino acids. These results show that the toxin was responsible for altering the translating process. Together with some earlier experiments it has been proved that the PR toxin was indeed active on the cell metabolism. [4] [6] Another interesting finding is the decreased activity of respiratory control and oxidative phosphorylation in the (isolated) mitochondria of the liver .
Apparently the amount of polysomes wasn't the determining factor, the inhibition was not decreased by increasing the amount of polysomes. The increase of pH 5 enzymes on the other hand, had a significant inhibitory effect. A higher concentration of pH 5 enzymes made the inhibitory effect less effective. These findings proved that the PR toxin was not altering the polysomes but in some way dysfunctions the pH 5 enzymes. [6]
When the PR toxin was directly administered to rats, protein synthesis in the liver was not as high as it normally would be. [6] This in vivo administration showed that the isolated cells from the rat's liver had a much lower transcriptional capacity. [4]
This paragraph needs attention from an expert in biology. The specific problem is: poor wording, meaning not clear.(March 2024) |
The process did not alter the uptake of amino acids in the liver, but the translational process was exclusively affected. The toxic effect of this toxin is as expected close with the fact that the process of protein synthesis is inhibited. However the real toxic effect could be that some required proteins aren't made in a proper amount. [6]
Multiple experiments have shown the different effects of PR toxin: it can cause damage to the liver and kidney, can induce carcinogenicity, and can in vivo inhibit DNA replication, protein synthesis, and transcription. [3] [ better source needed ] Most experiments on the effect of the PR toxin focus on the inhibition of protein synthesis and impairment of the liver. [4] [6] [3]
The PR toxin dysfunctions the transcriptional process in the liver. RNA polymerases I & II, the two main RNA polymerase systems in the liver, are affected by the toxin. The toxin needs no further enzymatic conversion to exert its effects on these systems. [4] The liver seems to be the most influenced organ by the PR toxin.
The toxicity of PR toxin was measured both intraperitoneally as well as orally. The first determined median lethal dose of pure PR toxin intraperitoneal in weanling rats was 11 mg/kg. The oral median lethal dose was 115 mg/kg. [1] The same study reported that ten minutes after an oral dose of 160 mg/kg, the animals experienced breathing problems that eventually led to death.
Acute Rat studies (mg/kg)
- LDLo test, via oral route: 115
- LD50 test, intraperitoneal route: 11.6
- LD50 test, intravenous: 8.2
Acute Mouse studies (mg/kg)
- LD50 test, via oral route: 72
- LD50 test, intraperitoneal: 2
- LD50 test, intravenous: 2
An acute human study has yet to be done, so no LD50 test results or doses are known yet. However, there is one case report from 1982 in which toxic effects are described on a human. This person was working in a factory in which the blue cheese was produced. The mold of Penicillium roqueforti was inhaled by this person and she developed hypersensitivity pneumonitis. Because of this lung inflammation, the person experienced among other things coughing, dyspnea, reduced lung volumes and hypoxemia. Antibodies against the mold were found afterwards in serum and lavage fluid. However, the LD50 values have not yet been determined. [8]
Studies of the effects on animals were done on mice, rats, anesthetized cats and preparations of isolated rat auricle. Toxic effects in mice and rats included abdominal writhing, decrease of motor activity and respiration rate, weakness of the hind legs and ataxia.
The effects were different for the different ways PR toxin was taken up. When the median lethal dose was ingested orally, the pathology was described as swollen-gas filled stomach and intestines as well as edema and congestion in the lungs. The kidney showed degenerative changes as well as hemorrhage.
If PR toxin was injected intraperitoneally, cats, mice and rats developed ascites fluid and edema of the lungs and scrotum. While intravenous injection showed, for the same animals, large volumes of pleural and pericardial volumes as well as lung edema.
In conclusion, the tissue cells and blood vessels were directly damaged by PR toxin. This caused leakage of fluid resulting among other things in edema of the lungs and ascites fluid. Also, the damage on the blood vessels resulted in increased capillary permeability. This increased permeability lead to a decrease in blood volume and direct damage to the vital organs including lungs, kidneys, liver and heart. [9]
Aconitine is an alkaloid toxin produced by various plant species belonging to the genus Aconitum, commonly known by the names wolfsbane and monkshood. Aconitine is notorious for its toxic properties.
Chlorfenvinphos is an organophosphorus compound that was widely used as an insecticide and an acaricide. The molecule itself can be described as an enol ester derived from dichloroacetophenone and diethylphosphonic acid. Chlorfenvinphos has been included in many products since its first use in 1963. However, because of its toxic effect as a cholinesterase inhibitor it has been banned in several countries, including the United States and the European Union. Its use in the United States was discontinued in 1991.
Ethion (C9H22O4P2S4) is an organophosphate insecticide. It is known to affect the neural enzyme acetylcholinesterase and disrupt its function.
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.
Penicillium roqueforti is a common saprotrophic fungus in the genus Penicillium. Widespread in nature, it can be isolated from soil, decaying organic matter, and plants.
Iproniazid is a non-selective, irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine class. It is a xenobiotic that was originally designed to treat tuberculosis, but was later most prominently used as an antidepressant drug. However, it was withdrawn from the market because of its hepatotoxicity. The medical use of iproniazid was discontinued in most of the world in the 1960s, but remained in use in France until its discontinuation in 2015.
Citrinin is a mycotoxin which is often found in food. It is a secondary metabolite produced by fungi that contaminates long-stored food and it can cause a variety of toxic effects, including kidney, liver and cell damage. Citrinin is mainly found in stored grains, but sometimes also in fruits and other plant products.
Patulin is an organic compound classified as a polyketide. It is named after the fungus from which it was isolated, Penicillium patulum. It is a white powder soluble in acidic water and in organic solvents. It is a lactone that is heat-stable, so it is not destroyed by pasteurization or thermal denaturation. However, stability following fermentation is lessened. It is a mycotoxin produced by a variety of molds, in particular, Aspergillus and Penicillium and Byssochlamys. Most commonly found in rotting apples, the amount of patulin in apple products is generally viewed as a measure of the quality of the apples used in production. In addition, patulin has been found in other foods such as grains, fruits, and vegetables. Its presence is highly regulated.
Benzotrichloride (BTC), also known as α,α,α-trichlorotoluene, phenyl chloroform or (trichloromethyl)benzene, is an organic compound with the formula C6H5CCl3. Benzotrichloride is an unstable, colorless or somewhat yellowish, viscous, chlorinated hydrocarbon with a penetrating odor. Benzotrichloride is used extensively as a chemical intermediate for products of various classes, i.e. dyes and antimicrobial agents.
Cylindrospermopsin is a cyanotoxin produced by a variety of freshwater cyanobacteria. CYN is a polycyclic uracil derivative containing guanidino and sulfate groups. It is also zwitterionic, making it highly water soluble. CYN is toxic to liver and kidney tissue and is thought to inhibit protein synthesis and to covalently modify DNA and/or RNA. It is not known whether cylindrospermopsin is a carcinogen, but it appears to have no tumour initiating activity in mice.
Chlorophacinone is a first-generation anticoagulant rodenticide. The mechanism of action results in internal bleeding due to non-functional clotting factors. It was used as a toxin to control rodent populations. It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.
Norbormide is a toxic compound used as a rodenticide. It has several mechanisms of action, acting as a vasoconstrictor and calcium channel blocker, but is selectively toxic to rats and has relatively low toxicity to other species, due to a species specific action of opening the permeability transition pores in rat mitochondria.
α-Naphthylthiourea (ANTU) is an organosulfur compound with the formula C10H7NHC(S)NH2. This a white, crystalline powder although commercial samples may be off-white. It is used as a rodenticide and as such is fairly toxic. Naphthylthiourea is available as 10% active baits in suitable protein- or carbohydrate-rich materials and as a 20% tracking powder.
Tutin is a poisonous plant derivative found in New Zealand tutu plants. It acts as a potent antagonist of the glycine receptor, and has powerful convulsant effects. It is used in scientific research into the glycine receptor. It is sometimes associated with outbreaks of toxic honey poisoning when bees feed on honeydew exudate from the sap-sucking passion vine hopper insect, when the vine hoppers have been feeding on the sap of tutu bushes. Toxic honey is a rare event and is more likely to occur when comb honey is eaten directly from a hive that has been harvesting honeydew from passionvine hoppers feeding on tutu plants.
Roquefortine C is a mycotoxin that belongs to a class of naturally occurring 2,5-diketopiperazines produced by various fungi, particularly species from the genus Penicillium. It was first isolated from a strain of Penicillium roqueforti, a species commercially used as a source of proteolytic and lipolytic enzymes during maturation of the blue-veined cheeses, Roquefort, Danish Blue, Stilton and Gorgonzola.
Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria. It is the most toxic of the microcystins.
Ethoprophos (or ethoprop) is an organophosphate ester with the formula C8H19O2PS2. It is a clear yellow to colourless liquid that has a characteristic mercaptan-like odour. It is used as an insecticide and nematicide and it is an acetylcholinesterase inhibitor.
4-Ipomeanol (4-IPO) is a pulmonary pre-toxin isolated from sweet potatoes infected with the fungus Fusarium solani. One of the 4-IPO metabolites is toxic to the lungs, liver and kidney in humans and animals. This metabolite can covalently bind to proteins, thereby interfering with normal cell processes.
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.