 The phallotoxins consist of at least seven compounds , all of which have seven similar peptide rings . <unk> was isolated in 1937 by Feodor <unk> , Heinrich Wieland 's student and son @-@ in @-@ law , and Ulrich Wieland of the University of Munich . Though phallotoxins are highly toxic to liver cells , they have since been found to add little to the death cap 's toxicity , as they are not absorbed through the gut . Furthermore , phalloidin is also found in the edible ( and sought @-@ after ) <unk> ( Amanita rubescens ) . Another group of minor active peptides are the <unk> , which consist of six similar <unk> <unk> . Like the phallotoxins , they do not induce any acute toxicity after ingestion in humans . 
