Non-Toxic Peptides from Amanita phalloides

Abstract

Cycloamanides have been denoted as a group of cyclic peptides, which, in contrast to the toxic peptides of Amanita phalloides, are soluble in acetone and can be extracted on partition between water and ethylacetate into the organic solvent. On exploring the lipophilic components of the mushroom, a non-toxic peptide, phallin A, was obtained in the crystalline state along with a toxic fraction (phallin B) (Wieland and de Vries 1966). Due to its minimal concentration, the toxic substance could not be well characterized; as regarded retrospectively, it may have been a mixture of phalloin and the peptide mentioned above. Interestingly, however, the toxic fraction was obtained by chromatography of a precursor fraction that had shown no toxicity, and, therefore, was suspected to contain a factor, which would be able to prevent the lethal, phallotoxin effect in mice. This hypothesis, later, could be substantiated by the isolation of a cyclic decapeptide, called antamanide (Wieland et al. 1968 b). A number of physiologically inert, cyclic peptides could be isolated and their structures elucidated in the following years (Gauhe and Wieland 1977).