Fungus Fact Friday

Tagged: chemistry

posts detailing chemicals and their interactions

#207: Ergot Alkaloids 0

Fungus Fact

#207: Ergot Alkaloids

Ergot Alkaloids (EAs) belong to a large class of mycotoxins. They are primarily produced by fungi in the genera Claviceps and Epichloë, although Claviceps purpurea is responsible for most of the impacts on humans. EAs are most common in rye, but can be found in any cereal grain. The toxins were a significant problem in the middle ages, but modern agricultural techniques mean that exposure to enough EAs to cause symptoms is extremely rare.1,2 Sources Many fungi produce ergot alkaloids in many different plant hosts. Humans are impacted most by species of Claviceps, which infect seeds of grasses. The most problematic species is C. purpurea (see FFF#061), which infects rye. A variety of other species infect cereal grains but cause less contamination. Livestock can be sickened by infected grain or by ergot alkaloids produced by endophytes in pasture grasses, most notably by Epichloë coenophiala.1–3 This post focuses on Claviceps and...

Ochratoxin-producing molds 0

Fungus Fact

#206: Ochratoxins

Unlike most other mycotoxins found in food, the ochratoxins are primarily produced during food storage. Fungi in the genera Aspergillus and Penicillium are common molds that decompose a variety of foods, from grains to coffee to grapes. In the process, many of those fungi produce ochratoxins, which can damage the kidneys and cause cancer in many animals. Ochratoxins presumably impact humans the same way, but researchers have so far been unable to directly link ochratoxins to any human disease. This is probably because human consumption of ochratoxins is usually very low.

Fusarium molds 0

Fungus Fact

#205: Zearalenone

Zearalenone is a fascinating mycotoxin produced by Fusarium species. It is the only mycotoxin that mimics the effects of the hormone estrogen. In high doses, it causes sexual organs to develop incorrectly. Pigs are the most susceptible animals and suffer estrogenism and vulvovaginitis when exposed to high levels of zearalenone. The toxin is present in many grain-based foods intended for human consumption, but usually at very low levels. As a result, zearalenone is generally harmless to humans.

Fusarium verticillioides spores 0

Fungus Fact

#204: Fumonisins

Humans have very little to worry about from fumonisins, mycotoxins produced by Fusarium fungi that cause Fusarium ear rot disease of corn (maize). The toxins are linked with esophageal cancer, but scientists cannot prove that they cause cancer. However, fumonisins are a major problem for horses and pigs. In horses, the toxins cause liquefaction of the brain tissue, while in pigs they cause the lungs to fill with water.

Fusarium head blight 1

Fungus Fact

#203: Deoxynivalenol

Deoxynivalenol (DON) is a toxin found in grains infected with the fungus Fusarium graminearum and other Fusarium species. It is often called “vomitoxin” because it primarily causes vomiting in humans and livestock. Its long-term effects are mild, but it is still a very important mycotoxin because it is the most common mycotoxin found in food.

Aspergillus flavus 3

Fungus Fact

#202: Aflatoxins

Fungi produce innumerable “mycotoxins” – compounds that are toxic to humans. In mushrooms, these cause symptoms ranging from gastrointestinal upset to death (see FFF#091–100 for more). Although these are of significant concern to mushroom hunters, their impact is relatively small. The most significant mycotoxins in terms of the number of people affected are produced by molds that naturally grow on food. Over the next few weeks, I will discuss some of the most problematic food-borne mycotoxins. Topping that list are the aflatoxins, which cause liver cancer and are especially problematic for people in developing nations.

#098: Psilocybin and Psilocin 7

Fungus Fact

#098: Psilocybin and Psilocin

These two toxins are the active chemicals in hallucinogenic mushrooms (often called “magic mushrooms” or “‘shrooms”). Psilocybin and psilocin belong to the LSD family of chemicals, but they are smaller than LSD and occur naturally in mushrooms.  These compounds can be found in a variety o f mushrooms, including many species in the genera Psilocybe, Conocybe, Panaeolus, and Gymnopilus.  Most often, the mushrooms eaten for their hallucinogenic effects belong to the genus Psilocybe, which lends its name to psilocybin and psilocin.

#097: Ibotenic Acid and Muscimol 1

Fungus Fact

#097: Ibotenic Acid and Muscimol

These two mushroom toxins impact the central nervous system and result in symptoms akin to alcohol intoxication. They are the primary toxins in the Fly Agaric, Amanita muscaria, and are responsible for the psychoactive affects of that mushroom.

#095: Coprine 1

Fungus Fact

#095: Coprine

Coprine is a fascinating molecule that is technically not poisonous. So why is it listed along with other mushroom toxins?  Because it can result in poisoning, but only if you consume a completely different toxin afterward, namely alcohol.  If you drink alcohol after eating a coprine-containing mushroom, you can expect to experience flushing of the face and neck, a rapid and/or irregular heartbeat, headache, nausea, and vomiting, and you may also experience difficulty breathing and tingling or numbness in the limbs or hands.  These symptoms last as long as the alcohol is in your system, which may be a while since coprine interferes with the body’s process of removing alcohol.

#094: Muscarine 1

Fungus Fact

#094: Muscarine

Muscarine is a toxin found primarily in small brown or white mushrooms in the genera Clitocybe and Inocybe. It is also found in other mushrooms, including the Fly Agaric, Amanita muscaria, but at much lower concentrations.  Muscarine was initially isolated in the 1860’s by the German chemists Oswald Schmiedeberg and Richard Koppe, who were trying to research the psychoactive properties of the Fly Agaric.  They isolated a compound – which they named muscarine after the Fly Agaric’s species name – that decreased heart rate in frogs and could even cause cardiac arrest when high concentrations were used.