Deadly amanita

Pig. 145.—Deadly amanita Amanita muscaria) showing volva at base of stem and frill, like stem ring. After Chestnut, V. K Bull. ITS, U. S. Dept. Agric., pi. i, Apr. 29. 1915.)... 

Fig. 146.—The deadly amanita, Amanita phalloides. Note the cup at the base oi the stipe. Gager, from photo by E. M. Kiltredge.i...

Don t eat this one The deadly Amanita tnuscaria contains muscarine and other toxic alkaloids. 

Toadstool (poisonous). Name for higher fungi from the group of basidiomycetes and ascomycetes that are toxic in both raw and cooked form. The toxins of the T. possess widely differing structures and activities. Thus, for example, the deadly amanita and the destroy-... 

PROBLEM 4.58 In Dorothy Sayers and Robert Eustace s mystery novel, The Documents in the Case (Harper Paperbacks, 1995), mushroom expert George Harrison is murdered by Harwood Latham. Latham doses Harrison s stew of Amanita rubescens with muscarine, the toxin of the related, but deadly. Amanita muscaria. Lathom hopes to make it look like an acci-... 

Amanita phattoides (deadly amanita, death angel) is characterized by an initial gastrointestinal phase however, because toxic principle is a hepatoc lular toxin,... 

Ahhreviationy. ATi apoptosis inducing fector, At f5 autophagy protein 5, LC3B microtubule-associated protein 1 light chain 3B, mtHSPJO heat shock protein 70 mitochondrial isoform, p62/SQSTMp62/sequestosome 1 Phalloidin is a toxin isolated from the deadly Amanita phalloides that binds directly F-actin... 

Several deadly species of the genus Amanita produce colorless toxic octapeptides, the amani-tins.a b Two residues of glycine, one of L-isoleucine, one of the unusual L-dihydroxyisoleucine, one of L-asparagine, and one of L-hydroxyproline are present in a-amanitin. In the center a modified tryptophan residue has been combined oxidatively with an SH group of a cysteine residue. If the dihy-droxyisoleucine residue of a-amanitin is replaced with unhydroxylated leucine, the resulting compound, known as amanullin, is nontoxic. The LD50 for mice is 0.3 mg kg 1 and 50 g of fresh Amanita phalloides may be sufficient to kill a person. Arnan-itins act slowly, and it is impossible to kill mice in less than 15 h, no matter how high the dose. 

The poisonous components of the most deadly mushroom Amanita phalloides (the Death Cap) are bicyclic heptapeptides which have an additional covalent bond that connects the ( -sulfur atom of an l-cysteine residue with the carbon atom in position 2 of the indole ring of the L-tryptophan. Phalloidin (or phalloidine) is the most abundant member of a whole family of related cyclic heptapeptides called phallotoxins (for a review, see Wieland1 1). These poisonous peptides, therefore, contain a cross-linking moiety consisting of L-tryptophan coupled to L-cysteine, designated tryptathionine (1), alternatively called 5-(trypto-phan-2-yl)cysteine or 2-(L-3-alanylsulfenyl)-L-tryptophan (Scheme 1). 

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. ... 

Many alkaloids are infamous for their strong toxicity towards animals and humans. Most of the deadly alkaloids fall into the class of neurotoxins (see above). The others have cytotoxic properties (Table 1.2). A cytotoxic effect can be generated when cell membranes are made leaky (as by saponins or steroidal alkaloids), or when elements of the cytoskeleton are inhibited. The spindle poisons vinblastine, vincristine, colchicine, and taxol are particularly famous. Actin filament formation is blocked by fungal poisons such as phalloidin from Amanita phalloides. 

Amanitas are a family of large, beautiful mushrooms that grow in many parts of the world. Some of them are deadly, the most poisonous of all wild mushrooms Some are edible and delicious. Two are neither deadly nor edible as food but are used as psychoactive drugs. 

It also should be noted that within the genus Amanita there exist several species of deadly mushrooms. They are among the small number of mushroom species the ingestion of which can prove fatal. These species include Amanita phalloides and Amanita viA, both of which contain small peptides called amanitins that inactivate RNA polymerase and cause irreversible damage to liver function. 

The fungus Amanita muscaria (the deadly poisonous fly agaric toadstool) contains >400 times more vanadium than is typical of plants, and the amount present is independent of the vanadium content of the soil in which the fungus grows. Amanita muscaria takes up the metal by using the conjugate base of (5,5)-2,2 -(hydroxyimino)dipropionic acid (H3L) to transport and store the trace metal as the V(I V) complex [VL2] , amavadin. 

The most serious form ofmycetism is produced by Amanita phalloides, other Amanita species, Lepiota, and Galerina species. These species account for >90% of fatal cases. Ingestion of as little as 50 g of A. phalloides (deadly nightcap) can be fatal. The principal toxins are the amatoxins (a- and (3-amanitin), a group of cyclic octapeptides that inhibit RNA polymerase 11 and hence... 

One should be very careful with field identification when collecting any mushroom to be eaten. This is especially tme in the present case, to avoid confusing Amanita muscaria or A. pantherina with one of their potentially lethal cousins. The deadly toxins alpha-wssadivA and phalloidin (and related cyclic polypeptides) have... 

Use For treatment of heavy metal poisonings. The racemate of L. is used in the treatment of liver diseases, including liver necrosis resulting from consumption of the deadly amantia (Amanita phalloides). L. is applied for therapy of diabetic neuropathy. For asymmetric synthesis of (i )-a-L., see Lit.. 

The investigation of the deadly poison of Amanita mushrooms was initiated at the beginning of this century in the USA. At Johns Hopkins University in Baltimore, MD, the bacteriologist William W. Ford attempted the isolation of the toxin, amanitatoxin , and succeeded in obtaining a preparation containing about 5% of the fatal agent without recognizing its peptide nature. The efforts were resumed in the thirties in the laboratory of Heinrich Wieland in Munich,... 

Bavaria, where in 1937 Ulrich Wieland and Feodor Lynen were able to crystallize for the first time a substance which was called phalloidin that rapidly killed mice after intraperitoneal application. Three years later Heinrich Wieland and Rudolf Hallermayer crystallized from Amanita phalloides extracts a second toxin, amanitin , which with smaller doses killed the experimental animals only after several days Uke a deadly dish of A, phalloides kills humans. Bernhard Witkop (Plate 49) 1940 in H. Wieland s laboratory recognized that phalloidin is a peptide and isolated a new imino acid, allo-hydroxyproline. Then the Second World War interrupted Amanita research which was resumed in Heidelberg by one of the present authors only ten years later and continued in Mainz, Frankfurt and again in Heidelberg through the following decades. 

---