Since the discovery in 1869 of muscarine, the intoxicating 
activity of Amanita muscaria has been attributed to this alka- 
loid. Recent studies, however, have indicated that muscarine 
represents a very minor constituent of the mushroom to which 
the strong inebriation could hardly be attributed. Trace amounts 
of bufotenine in the carpophores, likewise. could not be respon- 
sible, if indeed it be present. The reported presence of tropane 
alkaloids has been shown to be due to incorrect interpretation of 
chromatographic data. Other compounds detected in A. mus- 
caria are choline, acetylcholine and muscaridine (Eugster 1965; 
Wasser 1967; Wasson 1967). 
Recent chemical and pharmacological studies have shown 
that the principal biologically active constituents appear to be 
muscimol (XVI), the enolbetaine of 5-aminoethyl-3-hydroxy- 
isoxazole—an unsaturated cyclic hydroxamic acid which is 
excreted in the urine; and ibotenic acid (XVII), the zwitterion of 
a-amino-a-3-hydroxyisoxazolyl-S-acetic acid monohydrate. The 
less active muscazone (XVIII), likewise an amino acid [a-amino- 
a-2(3H)-oxazolonyl-5-acetic acid] is present in varying but lesser 
amounts. Structurally related to these isoxazoles is the antibiotic 
oxamycin, which often has psychoactive side effects in man: 
mental confusion, psychotic depression, abnormal behavior. 
Other active substances, still not structurally elucidated, are also 
known to be present (Eugster 1967; Hatfield et al. 1975; Wasser 
1967). 
se 
i + 
XVI —-O -C H-N Hy 
XVI -OH -CH-COO~ 
*NH 
155 
