ABSTRACT
Fungi are frequent contaminant of foodstuffs worldwide. According to environmental conditions and their own physiological particularities, they can develop on living plants in the field or during pre-harvest period as well as during storage in case of drying failure or re-moistening. During their evolution, the filamentous fungi have become one of the most important sources of secondary metabolites. Many of these secondary metabolites display properties interesting for pharmaceutical or food industry. But other metabolites, named mycotoxins, have several detriment effects on both human and animals. The variety of biological activities of fungal secondary metabolites is directly related to the large diversity of these metabolites in terms of chemical structures. This chemodiversity is largely due to the variety of not only “backbone” enzymes like polyketide synthases (PKS), isoprenyl disphosphate synthases, non ribosomal peptide synthetases (NRPS) and dimethylallyltryptophane synthases (DMATS) but also the tailoring enzymes involved in their biosynthesis. Mycotoxins can thus be classified into four main categories: polyketides, terpenes, non ribosomal peptides and hybrids.
319This chapter presents a detailed overview of some of the most representative mycotoxins of each of these categories with a special attention to mycotoxins that are regulated in a great number of countries: aflatoxins, fumonisins, ochratoxins, patulin, zearalenone and trichothecenes. For the non ribosomal peptides category, gliotoxin and ergot alkaloids have been chosen for their relevance in terms of occurrence and toxicity. This chapter includes information on the current understanding of the mechanisms of their toxinogenesis and summarizes their toxicological effects.
