Orellanine
Encyclopedia
Orellanine or Orellanin is a pyridine N-oxide and a crystalline alkaloid
that is found naturally in some lifeforms, specifically certain fungi
. It is also a mycotoxin
. It has been found in at least five species of mushrooms in the Cortinariaceae
family.
In 1962 he isolated a substance from the fungus. He named it orellanine after the Latin
name of the toadstool. Given orally to research animals, he produced the same reaction as in humans.
In 1973 orellanine was discovered in the toadstool Cortinarius rubellus.
s Antkowiak and Gessner in the last half of the 1970s discovered that it was a bipyridine
dioxide
. The more stable tautomer
is the amine oxide
form.
An interesting feature of orellanine is its ability to bind aluminium
ions to organic complexes.
and diquat
are toxic not only to plants, but also to animals including humans. Bipyridines with charged nitrogen atoms confound important redox
reactions in organisms, ‘stealing’ one or two electrons and sometimes bypass the electrons into other and often undesirable redox reactions. The terminal product can be peroxide
or superoxide
ions, the latter of which is harmful to the cells. It is likely that orellanine works in the same way, although the process from disturbed redox reactions to the serious clinical kidney damage has not been properly resolved.
In humans, a characteristic of poisoning by the nephrotoxin orellanine is the long latency; the first symptoms usually do not appear until 2–3 days after ingestion and can in some cases take as long as 3 weeks. The first symptoms of orellanine poisoning are similar to the common flu
(nausea
, vomiting, stomach pains, headaches, myalgia
, etc.), these symptoms are followed by early stages of renal failure
(immense thirst, frequent urination, pain on and around the kidneys) and eventually decreased or nonexistent urine output and other symptoms of renal failure occur. If left untreated death will follow.
The of orellanine in mice is 12 to 20 mg per kg body weight, where it must be noted that this is the dose which leads to death within two weeks. From cases of orellanine-related mushroom poisoning
in humans it seems that the lethal dose for humans is considerably lower.
against orellanine poisoning, early hospitalization can sometimes prevent serious injury and usually prevent death. Research is ongoing. Some treatments make use of anti-oxidant therapy and corticosteroids to help victims recover from their renal failure.
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
that is found naturally in some lifeforms, specifically certain fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
. It is also a mycotoxin
Mycotoxin
A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds. The term ‘mycotoxin’ is usually reserved for the toxic chemical products produced by fungi that readily colonize crops...
. It has been found in at least five species of mushrooms in the Cortinariaceae
Cortinariaceae
The Cortinariaceae are a large family of gilled mushrooms found worldwide, containing over 2100 species. The family takes its name from its largest genus, the varied species of the genus Cortinarius...
family.
History
In Poland during the 1950s there was a small epidemic where over 100 people became ill. What caused the illness remained a mystery until 1952 when Polish physician Dr. Stanisław Grzymala discovered that everyone suffering from the illness, which had by now claimed several lives, had eaten the mushroom Cortinarius orellanus.In 1962 he isolated a substance from the fungus. He named it orellanine after the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
name of the toadstool. Given orally to research animals, he produced the same reaction as in humans.
In 1973 orellanine was discovered in the toadstool Cortinarius rubellus.
Chemistry
The chemical constitution of orellanine remained unknown until the Polish chemistChemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
s Antkowiak and Gessner in the last half of the 1970s discovered that it was a bipyridine
Bipyridine
Bipyridines are a family of chemical compounds with the formula 2, which are formed by the coupling of two pyridine rings. Six isomers of bipyridine exist, but two isomers are prominent: 2,2'-bipyridine is a popular ligand in coordination chemistry and 4,4'-bipyridine is a precursor to the...
dioxide
Amine oxide
An amine oxide, also known as amine-N-oxide and N-oxide, is a chemical compound that contains the functional group R3N+-O−, an N-O bond with three additional hydrogen and/or hydrocarbon side chains attached to N. Sometimes it is written as R3N→O or, wrongly, as R3N=O.In the strict sense the...
. The more stable tautomer
Tautomer
Tautomers are isomers of organic compounds that readily interconvert by a chemical reaction called tautomerization. This reaction commonly results in the formal migration of a hydrogen atom or proton, accompanied by a switch of a single bond and adjacent double bond...
is the amine oxide
Amine oxide
An amine oxide, also known as amine-N-oxide and N-oxide, is a chemical compound that contains the functional group R3N+-O−, an N-O bond with three additional hydrogen and/or hydrocarbon side chains attached to N. Sometimes it is written as R3N→O or, wrongly, as R3N=O.In the strict sense the...
form.
An interesting feature of orellanine is its ability to bind aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
ions to organic complexes.
Toxicity
Bipyridines with positively charged nitrogen atoms were already known to be poisonous before the structure of orellanine was elucidated. The herbicides paraquatParaquat
Paraquat is the trade name for N,N′-dimethyl-4,4′-bipyridinium dichloride, one of the most widely used herbicides in the world. Paraquat, a viologen, is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings and animals...
and diquat
Diquat
Diquat is a contact herbicide that produces desiccation and defoliation most often available as the dibromide, diquat dibromide. Brand names for this formulation include Aquacide, Dextrone, Preeglone, Deiquat, Detrone, Reglone, Reglon, Reglox, Ortho-Diquat and Weedtrine-D.Diquat is a non-selective...
are toxic not only to plants, but also to animals including humans. Bipyridines with charged nitrogen atoms confound important redox
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
reactions in organisms, ‘stealing’ one or two electrons and sometimes bypass the electrons into other and often undesirable redox reactions. The terminal product can be peroxide
Peroxide
A peroxide is a compound containing an oxygen–oxygen single bond or the peroxide anion .The O−O group is called the peroxide group or peroxo group. In contrast to oxide ions, the oxygen atoms in the peroxide ion have an oxidation state of −1.The simplest stable peroxide is hydrogen peroxide...
or superoxide
Superoxide
A superoxide, also known by the obsolete name hyperoxide, is a compound that possesses the superoxide anion with the chemical formula O2−. The systematic name of the anion is dioxide. It is important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature...
ions, the latter of which is harmful to the cells. It is likely that orellanine works in the same way, although the process from disturbed redox reactions to the serious clinical kidney damage has not been properly resolved.
In humans, a characteristic of poisoning by the nephrotoxin orellanine is the long latency; the first symptoms usually do not appear until 2–3 days after ingestion and can in some cases take as long as 3 weeks. The first symptoms of orellanine poisoning are similar to the common flu
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
(nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, vomiting, stomach pains, headaches, myalgia
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
, etc.), these symptoms are followed by early stages of renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
(immense thirst, frequent urination, pain on and around the kidneys) and eventually decreased or nonexistent urine output and other symptoms of renal failure occur. If left untreated death will follow.
The of orellanine in mice is 12 to 20 mg per kg body weight, where it must be noted that this is the dose which leads to death within two weeks. From cases of orellanine-related mushroom poisoning
Mushroom poisoning
Mushroom poisoning refers to harmful effects from ingestion of toxic substances present in a mushroom. These symptoms can vary from slight gastrointestinal discomfort to death. The toxins present are secondary metabolites produced in specific biochemical pathways in the fungal cells...
in humans it seems that the lethal dose for humans is considerably lower.
Treatment
Although there is no known antidoteAntidote
An antidote is a substance which can counteract a form of poisoning. The term ultimately derives from the Greek αντιδιδοναι antididonai, "given against"....
against orellanine poisoning, early hospitalization can sometimes prevent serious injury and usually prevent death. Research is ongoing. Some treatments make use of anti-oxidant therapy and corticosteroids to help victims recover from their renal failure.
External links
- Cortinarius rubellus Pacific Northwest Fungi, Featured Fungus Number 4