Sterigmatocystin

Sterigmatocystin is a mycotoxin that is produced by several species of fungus, including Aspergillus versicolor and Aspergillus nidulans. It is a potent carcinogen and mutagen, and is particularly harmful to the liver and kidneys.

Structure and Properties

Sterigmatocystin is a xanthone derivative, and its structure is closely related to that of aflatoxin, another potent mycotoxin. It is a yellow, crystalline solid with a molecular formula of C18H12O6. It is soluble in organic solvents such as ethanol and methanol, but is poorly soluble in water.

Biosynthesis

The biosynthesis of sterigmatocystin involves a complex series of reactions, starting with the condensation of one molecule of acetyl-CoA and seven molecules of malonyl-CoA. This is followed by a series of oxidation and cyclization reactions, leading to the formation of the xanthone core. The final steps involve the addition of a hydroxyl group and a methyl group, resulting in the formation of sterigmatocystin.

Toxicity

Sterigmatocystin is a potent carcinogen and mutagen. It is particularly harmful to the liver and kidneys, and can cause hepatocellular carcinoma and renal cell carcinoma. It is also toxic to the immune system, and can cause immunosuppression.

Exposure and Risk

Exposure to sterigmatocystin can occur through the consumption of contaminated food or feed, or through inhalation of spores from contaminated materials. The risk of exposure is highest in areas with a warm and humid climate, where the fungi that produce sterigmatocystin are most prevalent.

Detection and Control

Methods for the detection of sterigmatocystin in food and feed include chromatography and mass spectrometry. Control measures include the use of fungicides, proper storage of food and feed, and regular testing for the presence of mycotoxins.

See Also

• Mycotoxin
• Aflatoxin
• Aspergillus versicolor
• Aspergillus nidulans