Gyromitra esculenta (Persoon ex Fries) mushrooms have been responsible for severe intoxications and even deaths. Clinical data are characterized primarily by vomiting and diarrhea and after a while by jaundice, convulsions and coma. Other Gyromitra species which may be of concern are G. fastigiata and G. gigas; nevertheless, recent advances in chromatography, biochemistry and toxicology have established that other species within the Ascomycetes may also prove toxic. Their toxins, mainly gyromitrin (N-methyl-N-formyl-N-acetyl-hydrazone) and their higher homologues are converted in the milieu of human stomach into N-methyl-N-formylhydrazine (MFH), then into N-methylhydrazine (MH). The toxicity of these latter chemicals, which are mainly hepatotoxic and even carcinogenic, has been established through in vivo and in vitro experiments with cell cultures and biochemical systems. Considering the chemical structure and the reactivity of these natural compounds, chemical and biochemical mechanisms are defined in order to explain their intrinsic biological activity. These findings imply that consumption of G. esculenta could present a carcinogenic as well as an acutely toxic health hazard.

Keywords: Gyromitra esculenta; mycotoxin; gyromitrin; N-methyl-N-formyl-N-acetyl-hydrazone; N-methyl-N-formyl-hydrazine