Muscaria toxicity

The Amanita genus comprises about 50 or 60 species, with vaiying chemical constituents—a number of which are toxic (Schultes and Hofman 1980, 1992). Fly agaric (Amanita muscaria) grows in widespread northern temperate zones of Eurasia and North America. In North... 

Contraindications Before harvesting these or any mushrooms for ingestion one should establish positive identification. Several closely related amanita species are extremely toxic. These include A. pantherina, A. virosa, A. verna, and A. phalloides (destroying angel). Large amounts of A. muscaria can also be fatal. Three mushrooms is the absolute maximum recommended. 

Wasson makes several interesting assertions about the toxicity of Amanita muscaria. Its alternate name—Fly Agaric—is said to come from the belief that flies can be killed by means of this mushroom. When Wasson tried the experiment, the flies became temporarily stupified but recovered. Although half of the references pronounce this species "deadly, Wasson claims that there isn t a single firsthand account of lethal poisoning. In fact, he asserts that "most trustworthy observers testify that, "properly dried, it has no bad effects. ... 

Amanita muscaria, A. pantheria (mushroom) (Agaricaceae) highly toxic, hallucinogenic fly agaric reputed aphrodisiac... 

Muscarine is especially interesting in that it is the poisonous constituent of the deadly toad-stool Aminita muscaria and of other poisonous fungi. It is a soluble, crystalline, tasteless compound of extreme toxicity. 

Don t eat this onel The deadly Amanfto muscaria contains muscarine and other toxic aHcaloids. 

NEUROTOXIN constituent of the fly agaric fungus Amanita muscaria and various /nocyfte spp. It is a very potent MUSCARINIC CHOLINOCEPTOR AGONIST with pronounced PARASYMPATHOMIMETIC actions. It is a HYPOTENSIVE, causes bronchoconstriction and stimulates gut, bladder and exocrine glands. Stereoisomers show only a fraction of the activity, and it is valuable as a pharmacological tool in studies on muscarinic receptors. It is very toxic orally, with stimulatory actions on the CNS (atropine sulphate may be used as an antidote). 

Chilton, KS. and J. Otti97(S. Toxic metabolites oiAmanitapantherina,A. cothum-ata, A. muscaria and oAiet Amanita species Lloydia 39(z 3) iyo-157. 

Muscazone is one of the potent neurologic toxins of Amanita muscaria. The toxic symptoms from high doses are similar to those of ibotenic acid. The LD50 data for this compound are not available. 

Although the search for the toxic principles of A. muscaria started at the beginning of the 1800s, attempts to obtain pure muscarine were not successful until 1957. In that year the outstanding scientist in muscarine chemistry, Eugster, in collaboration with Waser obtained muscarine chloride in pure crystalline form (mp 182-183°C, [a]o +8.1° (12). The structure of the alkaloid was determined a few years later by X-ray diffraction analysis (13). 

Muscazone an a-amino acid, M, 144, m.p. 190°C (d.), with a heterocyclic substituent of 2(3H)-oxazo-lone. M. occurs in the fly agaric (Amanita muscaria). It is readily formed from ibotenic acid by UV-irradia-tion of dilute aqueous solutions, whereby the isoxa-zole ring of 3-hydroxyisoxazole is converted into the 2(3H)-oxazolone system of M. M. is much less toxic than Ibotenic acid (see). 

Main toxic constit. of the fly fungus Amanita muscaria and various Inocybe spp. V. powerful parasympathomimetic agent causing hypotension and broncho-constriction. Stereoisomers show only a fraction of the activity. V hygroscopic. 

Amanitas, such as fly agaric (Amanita muscaria), contain a toxic derivative of isoxazole known as ibotenic acid (2-57), which is biosynthesised from glutamic add. Hallucinogenic effects also shows its dihydroderivative tricholomic (dihydroibotenic) acid (2-58), which is a component of Tricholoma muscarium mushrooms (see Section 10.3.2.9.3). 

A. muscaria), which concentrate vanadium to levels of up to 400 times those typically found in plants. These toxic toadstools contain a blue coloured complex (1 2) of V + cations with 2S,2 S)-N-hydroxyimino-2,2 -dipropionic acid, called amavadin (6-35). 

In addition to the main neurotoxin ibotenic acid, the fly agaric (A. muscaria) contains the toxic amine muscarine (10-216) in small quantities. Much higher amounts of this amine (about 500 times) occur in mycorrhizal fungi of the genus Inocybe that cause the muscarinic poisoning. The muscarine molecule has three asymmetric centres, thus can exist in eight stereoisomers, but only three muscarine isomers, epimuscarine (10-217), allomuscarine (10-218) and epiallomuscarine (10-219), have been found in nature. 

Choline nitrite, or pseudo-muscarine, was at one time thought to be identical with natural muscarine, the highly poisonous alkaloid of the mushroom Amanita muscaria (Fly Agaric), and to be the aldehyde corresponding to choline. Both suppositions are wrong. The natural alkaloid is much more toxic than choline nitrite, and its effects are antagonised by atropine, which has little protective effect against the synthetic ester. 

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