Amanita phalloides stereochemistry 6 structure analysis 6 ab initio calculation 4 carbon nuclear magnetic resonance 4 conference paper 4 cyclopeptide 4 empiricism 4 fungal protein 4 hydrogen bond 4 molecular interaction 4 nonhuman 4 protein conformation 4 protein isolation 4 protein structure 4 structure activity relation 4 toxic substance 4 toxicity 4 AM1 and ab initio studies 2 O-methyl-α-amanitin 2 S-deoxo-α-amanit in 2 alpha amanitin 2 alpha amanitin sulfone 2 alpha amanitin sulfoxide 2 amanitin 2 article 2 conformation 2 deoxo alpha amanitin 2 dipole 2 geometry 2