MOLECULE

Ergosterol

Ergosterol, also known as provitamin D2, belongs to the class of organic compounds known as ergosterols and derivatives. These are steroids containing ergosta-5,7,22-trien-3beta-ol or a derivative thereof, which is based on the 3-beta-hydroxylated ergostane skeleton. Thus, ergosterol is considered to be a sterol lipid molecule. Ergosterol is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Ergosterol is the biological precursor to vitamin D2. It is turned into viosterol by ultraviolet light, and is then converted into ergocalciferol, which is a form of vitamin D. Ergosterol can be extracted and converted to vitamin D to be used as a dietary supplement and food additive. Ergosterol is a component of fungal cell membranes, serving the same function that cholesterol serves in animal cells. Ergosterol is not found in mammalian cell membranes. Because many fungi and protozoa cannot survive without ergosterol, the enzymes that synthesize it have become important targets for drug discovery. Ergosterol powder is an irritant to skin, eyes, and the respiratory tract. Ingestion of large amounts can cause hypercalcemia, which (if prolonged) can lead to calcium salt deposits in the soft tissues and, in particular, the kidneys.