Trichothecene

A group of mycotoxins produced by various fungi

Trichothecenes are a group of mycotoxins produced by various species of fungi, particularly those belonging to the genera Fusarium, Myrothecium, Trichoderma, and Stachybotrys. These compounds are known for their potent toxicity and have been implicated in a variety of animal and human health issues.

Structure and Classification

Trichothecenes are sesquiterpenes characterized by a tricyclic 12,13-epoxytrichothec-9-ene skeleton. They are divided into four main types based on their chemical structure: Type A, Type B, Type C, and Type D. Each type has distinct functional groups that influence their biological activity and toxicity.

Chemical structure of trichothecenes.

Type A

Type A trichothecenes, such as T-2 toxin and HT-2 toxin, lack a ketone group at the C-8 position. They are among the most toxic trichothecenes and are known to inhibit protein synthesis.

Type B

Type B trichothecenes, including deoxynivalenol (DON) and nivalenol, possess a ketone group at the C-8 position. These compounds are commonly found in contaminated cereal grains.

Type C

Type C trichothecenes have an additional epoxide group, which increases their reactivity and potential toxicity.

Type D

Type D trichothecenes are characterized by a macrocyclic ring, which is formed by esterification of the hydroxyl groups. This structure is found in compounds like satratoxin and verrucarin.

Error creating thumbnail:

Classification of trichothecenes.

Mechanism of Action

Trichothecenes exert their toxic effects primarily by inhibiting protein synthesis in eukaryotic cells. They bind to the 60S ribosomal subunit, preventing the elongation of the polypeptide chain. This inhibition leads to cell death and apoptosis.

Error creating thumbnail:

Mechanisms of apoptosis control by trichothecenes.

Health Effects

Exposure to trichothecenes can cause a range of health effects, including gastrointestinal distress, immunosuppression, and dermatitis. In severe cases, exposure can lead to hemorrhagic syndromes and neurotoxicity.

Alimentary Toxic Aleukia

One of the most notorious outbreaks associated with trichothecenes is alimentary toxic aleukia (ATA), which occurred in the Soviet Union during the 1940s. This condition was caused by the consumption of moldy grain contaminated with trichothecenes.

Symptoms of alimentary toxic aleukia.

Decontamination and Control

Decontamination of trichothecene-contaminated materials is challenging due to their chemical stability. Methods such as deepoxydation and thermal degradation have been explored to reduce their toxicity.

Deepoxydation process for trichothecene decontamination.

Related Pages

• Mycotoxin
• Fusarium
• Deoxynivalenol
• Stachybotrys