nature

Ergot is what?

Table of contents:

Ergot is what?
Ergot is what?

Video: Ergot: the story of a parasitic fungus (1958). 2024, July

Video: Ergot: the story of a parasitic fungus (1958). 2024, July
Anonim

The ergot poisonous mushroom contains dangerous alkaloids, is a agricultural problem and is also artificially grown for pharmaceutical purposes. Its rapid spread to crops in the Middle Ages led to epidemics as a result of eating bread from infected flour.

Much in nature is arranged in an amazing way, and that which can kill, at the same time, can heal.

Image

What is ergot?

Ergot is a genus of fungi from the family of the same name. All of them parasitize on cereal plants, including rye and wheat. You can find another option for the name of the fungus - uterine horns. The name "ergot" comes from the old Russian word and means "abundance, excess." Such a paradoxical meaning, according to the linguist O. N. Trubachev, in those days was euphemistic in nature.

Fungal sclerotia are oblong, rarely trihedral, hard formations of a curved shape with cracks and longitudinal wrinkles. The surface is black-violet, sometimes with a white coating, which is easily erased, the color on the fault is white or with a yellow tint. The length of sclerotia depends on the type of cereal on which ergot develops (photo above). For example, in rye it is 1-3 cm, and the diameter is up to 6 mm.

Ergot in the Middle Ages

The poisoning of animals and humans with ergot alkaloids has its own name - ergotism. The phenomenon, by the way, is scientifically proven and had a mass character in the Middle Ages. At that time, rye undemanding to soils and resistant to pests was grown everywhere, and bread was a staple food. The infected grain turned into flour and thus fell on the table. Ergotism caused large-scale epidemics, and even there was a special Order of the Anthony, treating infected people.

Image

Professor Shane Rogers from Clarkson University, together with his graduate students, studied the problem of ghosts and came to the conclusion that in many houses where strange sounds or visions were observed, some dangerous types of mold that could affect residents were thriving. This theory confirms the conjecture about the influence of ergot on events in medieval Europe, including witch hunts, crusades. In the photo above - the canvas of the Flemish artist depicting the consequences of the epidemic of ergotism.

Ergot is a parasitic mushroom with alkaloids, which, according to some reports, cause not only poisoning, but also hallucinations, convulsions, and itching. Stories of these symptoms are known as “witch cramps” and “Anthony fire”. Alkalodides are not destroyed even after heat treatment (baking bread). Such behavior of patients against the background of religious fanaticism led to tragic consequences.

Mushroom development cycle

The fungal mycelium has a reddish tinge, its formation occurs in the spring, it has the appearance of legs with heads on top of which there are bottle-shaped fruit bodies (peritheum), clearly visible in the photograph below. In the latter, the sexual process proceeds, which is a fusion of gametanglia, resulting in the formation of a zygote. She immediately enters the division (meiosis) inside the bag (asuka), formed from the mycelium of the fungus.

Image

After that, in the summer, ergot seeds (spores) are carried many kilometers around by wind or insects. Once in the pestle of a flowering cereal plant, they germinate, and ultimately not a grain is formed, but a fungus mycelium. It produces a special juice that attracts insects (honey dew). In this way, the fungus spreads further through spores. After the ovary is depleted, in its place the so-called sclerotia is formed - a horn formed by fused fungal hyphae. When the cereal ripens, it falls to the ground and hibernates in the soil, and in the spring the process repeats again.

Mushroom in agriculture

Special cultivation of ergot is important to compare with the harm from it in agricultural fields. According to international standards, the content of spores of poisonous mushrooms in grain should not exceed 0.05%. However, some countries demand the absolute absence of disputes in raw materials, in particular Egypt. Ergot spreads quickly enough and in one quantity or another is always present in the fields. According to experts, to bring its content in the finished grain to zero is extremely difficult, but theoretically possible.

Image

The most common ergot is wheat, rye and barley. The main measure to combat the fungus is thorough cleaning of all seed material from the horns, as well as autumn (autumn) tillage after harvesting. Sclerotius dies when it is plowed. As a precautionary measure, it is recommended to choose varieties with short and simultaneous flowering periods for sowing and observe crop rotation rules.

Factors contributing to the spread of ergot are cereal weeds and predecessors in the fields, an abundance of rainfall in conjunction with the wind during the flowering period of cereals, cold and cloudy weather, which leads to a stretching of the flowering period.

Propagation and cultivation

It should be noted that ergot is a fungus common wherever there are cereal crops. The most favorable climatic factor for it is high air humidity (from 70%).

Image

As mentioned above, for pharmaceutical purposes, the fungus, namely the ergot purple, is specially grown. For this, there are state farms of medicinal plants, in particular in the Novosibirsk and Kirov regions of Russia, in Belarus. Ears of rye are specially infected with spores of the fungus manually or by injection machines. Productivity in this case reaches 4 centners per hectare.

The collection of raw materials is carried out during the ripening period, when the horns are painted in a purple-brown color, harden and are easily separated from the ear. The collected material is dried in well-ventilated workshops with blackout. Requirements for finished raw materials: humidity not more than 11% and the presence of impurities in an amount of less than 1.5-2%.

Ergot alkaloids

In pharmacy, ergot horns (sclerotia) are used. They contain six stereoisomeric pairs of alkaloids. Each active levorotatory corresponds to the least weak dextrorotatory isomer. In particular, ergotamine and ergotamine, ergocristin and ergocristinin, ergosin and ergosimin, ergocriptine and ergocriptinin, etc. The main component of all left-handed alkaloids is lysergic acid. The composition and content of alkaloids depend on the biological race of the fungus, external factors and the host plant.

Getting LSD

Image

In 1938, a Swiss chemist Albert Hofmann (pictured above) from a derivative of lysergic acid contained in ergot chemically obtained a drug - the infamous LSD. After 5 years, the same person discovered the hallucinogenic properties of the compound. Currently, LSD in most countries of the world is prohibited by the UN Convention, as well as the process of its research. Switzerland is an exception: since 2008 it has been allowed to conduct drug therapy on its territory for terminally ill patients, including those at critical stages of cancer.