Mycotoxins can be produced in parent structure form — like deoxynivalenol (i.e., DON or “vomitoxin”), for example — or may be modified into numerous structurally-related compounds (i.e., DON-3-glucoside) that are often called “masked mycotoxins.” These modifications may be completed by the fungus itself or by the host plant on which the fungus is growing.

For the host plant, the formation of masked mycotoxins happens through a method of detoxification, as these compounds are often less toxic for the plant. The “masking” process usually involves the addition of a glucose or sulfate group. Although this process may reduce the toxicity to the host plant itself, these masked mycotoxins may remain toxicologically relevant for humans and animals, as the gastrointestinal tract can cleave back to the original mycotoxin.

Modified mycotoxins can form when the parent structure is modified by the fungal organism. An example is the production of altered forms of DON, such as 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol.

Modification can also occur within humans and animals when mycotoxins are altered due to metabolism, such as when aflatoxin B1 is converted into aflatoxin M1. The process of modifying mycotoxins may cause these compounds to become either more or less bioavailable, resulting in compounds with either more or less toxicity.

The lesser-known, or newer, forms of mycotoxins are “emerging mycotoxins.”

This term, which covers a range of mycotoxins, refers to the theory that these are newer classes of mycotoxins that are neither routinely analyzed nor legislatively regulated.

Mycotoxins that fall into this category include enniatins, beauvericin and moniliformin. Information on their occurrence and toxicity is limited, although these mycotoxins have garnered more attention in recent years.

What are MASKED mycotoxins?

Mycotoxins can be produced in parent structure form, for example deoxynivalenol (i.e. DON or “vomitoxin”), or may be modified into numerous structurally-related compounds (i.e. DON-3-glucoside) that are often termed “masked mycotoxins.” These modifications may be completed by

the fungus itself or by the host plant on which the fungus

is growing.

For the host plant, formation of masked mycotoxins is a method of detoxification as these compounds are often less toxic for the plant. The “masking” process usually involves the addition of a glucose or sulfate group.

Although this process may reduce the toxicity to the host plant itself, these masked mycotoxins may remain toxicologically relevant for humans and animals, as the gastrointestinal tract can cleave back to the original mycotoxin.

What are modified mycotoxins?

Modified mycotoxins may be formed when there is a modification of the parent structure form by the fungal organism.

An example is the production of altered forms of DON, such as 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol.

Modification can also occur within humans and animals when mycotoxins are altered due to metabolism, such as when aflatoxin B1 is converted into aflatoxin M1.

The process of modifying mycotoxins may cause these compounds to be more or less bioavailable, resulting in compounds with either more or less toxicity.

What are emerging mycotoxins?

The lesser known, or newer forms of mycotoxins are “emerging mycotoxins”.

This term covers a range of mycotoxins, but refers to the concept that these are newer classes of mycotoxins that are neither routinely analyzed or legislatively regulated.

Mycotoxins that fall into this category include enniatins, beauvericin and moniliformin. Information on occurrence and toxicity is limited, although more attention has been paid to these mycotoxins in recent years.

detecting masked, modified and emerging mycotoxins.

Thankfully, there are methods for identifying and combatting these varieties of mycotoxins.

Although rapid tests and enzyme-lined immunosorbent assay (ELISA) technologies can provide valuable information about the parent mycotoxins and even some of the modified mycotoxins, advanced laboratory techniques such as liquid chromatography with duel masked spectrometry (LC-MS/MS) need to be employed to detect most masked, modified and emerging mycotoxins.

Author: Alexandra Weaver, Alltech Mycotoxin Management

References available on request