AMINES 273 



5. AMINES 



Although only one specific decarboxylase activity — glutamic decar- 

 boxylation, yielding y-aminobutyric acid — is known in fungi (p. 265), 

 the number of amines which occur and which presumably originate 

 by decarboxylation of known amino acids is large. Sclerotia of Clavi- 

 ceps purpurea yield histamine, tyramine, isoamylamine, agmatine, pu- 

 trescine and cadaverine (503, 508, 586). Occasional reports — not all 

 certain — suggest that putrescine, phenylethylamine, isoamylamine, and 

 cadaverine occur in fruit bodies of basidiomycetes (291, 310, 499, 580). 



A mutant of Aspergillus nidulans requires putrescine for growth, and 

 the requirement is not met by L-ornithine or by other amines (488). 

 Several fungi act on histamine (585). Amines are in general poor or 

 unavailable sources of nitrogen (278). 



Muscarine, the toxin of Amanita muscaria, is an amine; Eugster 

 (146) reviews earlier studies; a new structure has been confirmed by 

 synthesis (301). 



Choline has been found as a constituent of several fungi (508, 581); 

 whether, however, it occurs in the free state or only in phospholipids 

 (Chapter 2) has not been determined. A single report (147) suggests 

 that acetyl choline is a constituent of ergot. Cyclic choline sulfate has 

 been mentioned (Chapter 2). 



Barley and other grains scabbed by Fusarium graminearum or other 

 related Fusarium spp. contain a water-soluble material toxic to animals 

 (101); identification of this substance with choline has been shown 

 (473) to be in error. 



Choline is required by mutants of Neurospora crassa (246), and a 

 mutant can be used for the bioassay of choline (249, 527). The synthe- 

 sis of choline by successive methylations of aminoethanol has been 

 described (Chapter 6). 



Trimethylamine has been isolated from numerous basidiomycetes, 

 e.g., Tilletia levis, Phallus impudicus, and Russula aurata (225, 499, 

 580), and from Claviceps purpurea (508). In plants and in bacteria 

 trimethylamine arises from choline (98), and the same origin may be 

 proposed in fungi. 



Betaine, (CH 3 ) 3 — N+ — CH 2 — COO-, has been isolated from fungi 

 (581), but, as with all the amines found in gross studies, there is some 

 doubt as to whether it occurs as such or combined. One such combined 

 form of betaine, ergothioneine, has the structure of the trimethyl beta- 

 ine of thiolhistidine: 



