Specification & Spread
Ergot claviceps of ergotamine (ergotoksine) strain— cornua secalis cornuti stamm ergotamini (ergotoxini)
Ergot — claviceps purpurea (fries) tulasne
Clavicipitaceae — clavicipitaceae
Cup fungus subfamily — ascomycota
Ergot is a fungus parasitic on cereals, mainly on rye. The development cycle includes three stages:
- marsupial and
- conidial. The fungus is of medical importance in the sclerocial stage.
Stage I - the formation of sclerotia - resting stage of the fungus. Sclerotia («ergot claviceps») develop in rye flowers as a result of growth and dense plexus of mycelium hyphae, it is elongated solid formations of black and purple colour, 1-3 cm long. Sclerotia fall off from mature rye ears or appear on the ground with grain. It tolerates frost well and begins to germinate in the spring.
Stage II - so-called stroma appears on the growing sclerotia, consisting of a thin stalk and a spherical reddish-violet head, seated with numerous small conical protrusions - outcrops of fruiting bodies (peritecias) - ovoid cavities formed in the peripheral part of the head. In the perithecia, numerous bags (asci) of club-shaped form develop, in each of which 8 filamentary ascospores develop. By the time of rye flowering, the fruiting bodies of the fungus are fully ripe, bags burst out of the mucous swellable stromas, which burst, ascospores are thrown out of the perithecia, and air currents spread along the flowering rye.
Stage III begins with the fall of ascospores on the feathery stigmas of rye flowers and its germination. A mycelium (mycelium) is formed from the hyphae plexus on the flower ovary, as it develops asexual reproduction of the fungus begins. It consists in the formation of hyphae-conidiophores, separating unicellular colorless conidiospores, at the same time stands out sticky sugary liquid, called «honey dew». The drops of «honey dew» flow down over the affected ear, taking with it conidiospores. The sweet liquid attracts insects, which, flying on other spikes, spread conidiospores, thereby contributing to a new infection of rye. Conidiospores, hitting healthy rye flowers, also germinate, forming a mycelium on the ovary. Gradually, the mycelium of the fungus, expanding, destroys the ovary, and instead of grain a white oblong large fungal body develops - young sclerotia. By the time ripening rye ripen and sclerotia; hyphae compacted, the outer layer of sclerotia is pigmented, staining in dark purple colour. With a strong lesion of rye, there may be up to 3-4 sclerotia on individual ears. Further, when harvesting bread, sclerotia spontaneously fall to the ground or, during threshing, fall into the marketable or seed grain.
Spreading. In Russian ergot is found in all natural zones, except for deserts and tundra, its range is associated with the area of cultivation of rye.
Habitat. The most favorable for the development of ergot are areas with high relative humidity and moderately warm weather during the flowering period of rye. The optimum temperature for the growth and development of ergot is 24 ºС.
Sclerotia contain alkaloids - derivatives of indole, which can be divided into two groups: derivatives of lysergic acid and alkaloids of the clavine series (penniclavin).
The first group is represented by 7 pairs of stereoisomeric compounds. The levorotatory isomers have a high biological activity, while dextrorotatory is a little active. Alkaloids - acid derivatives of lysergic - divided into 4 types:
- alkaloids peptide series (ergotamine group, ergotoxine and so on),
- alkaloids of alkanolamide type (ergometrine and ergometrinine),
- alkaloids of amide type (ergine and erginine),
- alkaloids of karbinolamide type (acid alpha-lysergic methylcarbinolamide).
The amount of alkaloids in the raw material of ergotamine strain contains about 70% ergotamine, ergotoxine strain contains about 70% ergotoxine, ergocryptine strain contains about 80% ergocryptin, ergometrine strain contains only ergometrine and ergometrine. In addition to alkaloids, sclerotia contain free amines and amino acids, up to 35% fatty oil, lactic acid, sugars, pigments.
Harvesting and storage of raw materials
Harvesting. For uninterrupted satisfaction of the needs of the pharmaceutical industry in this type of the raw material, ergot has been introduced into culture. The production of ergot in specialized farms consists of several stages:
- cleaning the «ergot claviceps»,
- obtaining infectious material,
- infection of rye.
The infection is carried out with the help of special machines at the beginning of earing rye with an infectious material grown on artificial media containing ergot conidiospores. Sclerotia harvesting is carried out as it matures using special machines. The possibility of artificial cultivation of ergot made it possible to obtain sclerotia with a high content of alkaloids, as well as to carry out selection work aimed at obtaining strains of the fungus that produce a certain set of alkaloids. Currently, there are four strains of ergot: ergotamine, ergotoxine, ergocriptine and ergometrine. The first two strains are introduced into production. Abroad mastered industrial saprophytic culture of ergot.
Drying. Sclerotia are dried in a dryer at a temperature of 40 ºС. Higher temperature leads to the decomposition of alkaloids.
Storage. When it is stored, the «ergot claviceps» are often damaged by granary pests (mites, caterpillars of the grain moth, the larvae of the bread grinder), so they must be stored in a dry, previously disinfected room.
External signs of raw materials
The «ergot claviceps» are oblong, almost trihedral, somewhat curved, tapering towards both ends, usually with three longitudinal grooves.
The length is 5-30 mm, the width is 3-5 mm, the colour outside is black or brown-purple, sometimes greyish, with washable bloom.
«Ergot claviceps» are brittle, the kink is smooth, whitish, on the periphery with a narrow brownish-purple border.
The smell is weak, peculiar. The taste is not determined(!).
Properties and application
The pharmacological properties of ergot
Ergot alkaloids have a complex effect on the body.
One of the characteristic pharmacological features is its ability to cause uterine contraction (especially pronounced in ergotamine and ergometrine),
Another feature of ergot alkaloids (especially its dihydrogenated forms) is the alpha-adreno-blocking activity, which allows it to be used in cardiovascular diseases. Currently in world practice about 30 drugs based on ergoalkaloids are known.
Alkaloid poisoning with ergot (ergotism), which occurs when eating infected rye bread, proceeds in a convulsive form or in the form of gangrene of the extremities due to irreversible narrowing of the capillaries.
Application of ergot
Earlier, ergot preparations were used only in obstetric-gynecological practice to enhance uterine contractions and stop uterine bleeding. Currently, the range of application of ergot alkaloids has expanded significantly.
Ergotamine tartrate and ergotoxine, along with alkaloids of belladonna, are used as antispasmodic, sedatives for increased excitability, insomnia, menopausal neurosis, neurodermatitis, vegetative dystonia.
Ergotamine tartrate and caffeine, are used for migraine, hypotension. Water-soluble alkaloid ergometrine has a stronger and faster stimulating effect on the muscles of the uterus than other ergot alkaloids, and is more often used in obstetric and gynecological practice.
From ergocryptine strain get alkaloid:
- ergocryptin, which is used for breast tumors.
Dihydrogen ergot alkaloids are widely used for alpha-adrenergic blocking action in the treatment of cardiovascular diseases.
Clavine alkaloids are not yet used in medical practice.
Pregnancy and lactation period, angina pectoris and peripheral vasoconstriction, glaucoma, abnormal liver and kidney function, septic conditions, late stages of atherosclerosis and hypertension, peptic ulcer of the gastrointestinal tract, and during epilepsy, preparations containing ergot are taken with caution.