Mycotoxins as secondary metabolites

Bu Lock J D 1980 Mycotoxins as secondary metabolites. In Steyn P S (ed) The biosynthesis of mycotoxins. Academic Press London New York, 1-16... 

Mycotoxins are defined as secondary metabolites of mould growth which are generally believed to be produced in response to stress factors acting on the fungus. Individual moulds, fungi or mycotoxins rarely occur in isolation... 

Figure 19.1 Representative compounds of the large numberof mycotoxins produced as secondary metabolites by fungi.

Mycotoxins are toxic substances produced by molds and fiingi, such as mushrooms. These toxic substances, known as secondary metabolites, are by-products of metabolism that are inessential to fungal growth. Although some mycotoxins can be used for medicinal purposes, most are poisonous if eaten in sufficient quantity. 

Mycotoxins are secondary metabolites of molds (primarily deuteromycetes), which are generally produced under optimum conditions at the end of the exponential growth phase. The term mycotoxin combines the terms mykes, the Greek word for molds, and toxicum, the Latin word for toxic or poisonous. Accordingly, mycotoxins occasionally also are defined as... 

Mycotoxins are secondary metabolites of fungi which can cause acute toxic, mutagenic, teratogenic, and carcinogenic effects in animals. The fact that mycotoxins, such as aflatoxin, are among the most potent animal toxins and carcinogens known, warrants concern about the contamination of the human food supply, including dairy products, with mycotoxins. 

In the United States, studies on aflatoxins incriminated aflatoxins as the cause of epizootic hepatitis in dogs and as the cause of moldy com poisoning in pigs [12], Aflatoxins (AFs) are a family of structure-related mycotoxins produced as secondary metabolites by the spoilage of fungi Aspergillus, particularly A. flavus and A. parasiticus [13-15],... 

Mycotoxins are secondary metabolites of fungi, belonging essentially to the Aspergillus, Penicillium, and Fusarium genera, that can be found as food contaminants. These products are responsible for many different... 

Approximately 1200 secondary fungal metabolites were known in 1978,122 and the number at present has reached to more than 6000.109 Approximately 10% of the 6000 metabolites are classified as mycotoxins. The number of secondary metabolites yet to be discovered may be quite large since it is estimated that we know around 5% fungal species out of the world s total fungal species.123,109 Therefore, the number of mycotoxins will probably increase in future. 

Molds also produce complex products of secondary metabolism. These secondary metabolites include chemicals used to ensure that the molds maintain their niche within their current habitat. These chemicals may suppress the growth of bacteria or other molds (antibiotic effect), or may be toxic to other eukaryotic cells (mycotoxic effect),. Mycotoxins may function as inhibitors of DNA, RNA, and protein synthesis. The production of secondary metabolites... 

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