Alternaria toxins

Alternaria toxins represent a possible health-endangering group of mycotoxins produced mainly by the Alternaria species. These are a widespread group of fungi contaminating mainly fruits and vegetables, but also other crop plants, during growth as well as storage. The most important mycotoxin-producing species is Alternaria alternata which occurs mainly on cereals and seeds but also on olives, various fruits and tomatoes. A vast number of Alternaria mycotoxins are known to occur naturally on infected crops, fruits and vegetables, including tenuazonic acid, alternariol, alternariol monomethyl ether, altenuene and altertoxin I. Structurally, these toxins are related to fumonisins.

Even though Alternaria toxins are normally associated with fruits and vegetables that are visibly infected by Alternaria rot, they have also been found in cereals, such as wheat, rye, sorghum, rice and even tobacco. Alternaria toxins have been shown to exhibit both acute and chronic effects and therefore represent a threat to animal and human health. The most studied mycotoxin in the group of toxins produced by the species Alternaria is tenuazonic acid. Its main function is the inhibition of protein synthesis and results in antitumor, antiviral and antibacterial activity. Most of the other Alternaria toxins show cytotoxic activity in mammals, some of them are mutagenic like the altertoxins, while others are toxic to the unborn like alternariol and alternariolmonomethyl ether.

Currently no guidelines or legislative limits are set for Alternaria toxins. So far it has been of general belief that their occurrence in food is very low and therefore the risk of human exposure is very limited. Nevertheless, data for their risk assessment is currently collected and methods for the detection of Alternaria toxins based on liquid chromatography – massspectrometry (LC-MS) are under development.

This article was published in our Spot On magazine

Other interesting topics In this issue:

  • Emerging Mycotoxins - A Treat beyond Regulations
  • Ergot Alkaloids - an ancient story
  • How to develop an LC-MS/MS-based Multi-Mycotoxin Method

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