292 PHYSIOLOGY OF THE FUNGI 



enough quantities by man or animals, they cause ergotism, a disease also 



known as St. Anthony's fire. 



C. purpurea has been cultured under laboratory conditions but forms 



neither sclerotia nor alkaloids under these conditions (Michener and 



Snell, 1950). Apparently alkaloids are formed only in the sclerotia. 



Ergotamine, when added to mycelial cultures of C. purpurea, was largely 



destroyed. 



TOXINS 



Numerous toxic substances are produced by fungi in nature, and their 

 effects on man and animals are varied. The most severe toxins are 

 produced by some of the Agaricaceae, particularly by species of Amanita. 

 It is not known whether the toxins are present in the mycelium of these 

 species as well as in the fruit bodies. A few of the outstanding examples 

 of fungus toxins will be discussed briefly. 



Amanita toxin (phalloidin) is stable to heat and drying and to the action 

 of digestive juices. The great majority of the deaths due to mushroom 

 poisoning are caused by Amanita phalloides, A. virosa, and A. verna, 

 which contain amanita toxin. The action of this toxin is slow, the symp- 

 toms being delayed for 6 to 15 hr. after the mushrooms are eaten. By 

 this time the toxin has been absorbed, and the patient seldom responds 

 to treatment. No antidote for this toxin is known. The mortality rate 

 is high, varying from 60 to 100 per cent (Fischer, 1918). In addition to 

 the three species of Amanita mentioned above, the same or a similar toxin 

 is present in A. spreta, A. porphyria, A. strohiliformis, A. radicata, and 

 A. chlorinosma. Hygrophorus conicus and Pholiota autumnalis produce 

 similar symptoms and may contain this toxin (Krieger, 1936). 



About 1 g. of pure crystalline toxin can be extracted from 40 kg. of 

 A. phalloides fruit bodies. The toxic dose for white mice is 50 jug; death 

 results in from 1 to 2 days. Chemically, phalloidin is a polypeptide 

 containing six amino-acid residues. Wieland and Witkop (1940) report 

 that phalloidin, on hydrolysis wdth sulfuric acid, yields 1 mole each of 

 Z-Q!-oxytryptophane and cysteine, and 2 moles each of ^-hydroxy proline b 

 (not found in protein digests) and /-alanine. Kuhn et al. (1939) found 

 methionine in addition to cysteine (ratio 1 to 5) in phalloidin. Among 

 the antibiotics, gramicidin and tyrocidine are polypeptides which contain 

 "unnatural" amino acids and are toxic when injected into experimental 

 animals. 



Muscarin is the principal toxic agent present in A. muscaria. It is a 

 quick-acting toxin, producing symptoms within 1 to 6 hr. after being 

 consumed. The patient usually responds well to treatment and recovery 

 is rapid, although death may occur. Atropin is an antidote for muscarin 

 which is closely related to choline. Muscarin has also been demonstrated 

 in A. pantherina, Russula emetica. Boletus luridus, and B. satanas. A 



