Title: Ergosterol
CAS Registry Number: 57-87-4
CAS Name: (3b,22E)-Ergosta-5,7,22-trien-3-ol
Additional Names: ergosta-5:6,7:8,22:23-trien-3-ol; ergosterin
Molecular Formula: C28H44O
Molecular Weight: 396.65
Percent Composition: C 84.78%, H 11.18%, O 4.03%
Literature References: Most important of the provitamins D. Usually obtained from yeast which synthesizes it from simple sugars such as glucose. Damp yeast yields about 2.5% ergosterol, the variety of the yeast being very important. Isoln procedure: Green et al., US 3006932 (1961 to Vitamins Ltd.). When irradiated with uv light, ergosterol develops powerful vitamin D2, q.v., activity. Askew et al., in England and Windaus and collaborators in Germany isolated the antirachitic vitamin D2. The main irradiation products of ergsterol are lumisterol®tachysterol®vitamin D2. Structure: Chuang, Ann. 500, 270 (1933). Oxidation products: Fuerst, Arch. Pharm. 300, 144 (1967).
Properties: Small hydrated plates from alcohol, in hydrated needles from ether. The best crystallized form contains 1½ mol H2O, mp 168°: Bills, Honeywell, J. Biol. Chem. 80, 15 (1928). Complete removal of water is almost impossible and results in an amorphous mass, melting range 166-183°. bp0.01 250°. [a]D20 -135° (c = 1.2 in CHCl3 calcd as anhydr). [a]20546 -171° (CHCl3). uv max (ethanol): 262, 271, 282, 293 nm, Hogness et al., ibid. 120, 239 (1937). Practically insol in water. One gram dissolves in 660 ml alcohol, in 45 ml boiling alcohol, in 70 ml ether, in 39 ml boiling ether, in 31 ml chloroform. Precipitated by digitonin. Affected by light and air, turns yellow. Oxygen forms peroxides and hydrogen may form polyhydro compds.
Melting point: mp 168°: Bills, Honeywell, J. Biol. Chem. 80, 15 (1928)
Boiling point: bp0.01 250°
Optical Rotation: [a]D20 -135° (c = 1.2 in CHCl3 calcd as anhydr); [a]20546 -171° (CHCl3)
Absorption maximum: uv max (ethanol): 262, 271, 282, 293 nm, Hogness et al., ibid. 120, 239 (1937)
Derivative Type: Acetate
Molecular Formula: C30H46O2
Molecular Weight: 438.69
Percent Composition: C 82.14%, H 10.57%, O 7.29%
Properties: mp 179°, clear at 181°.
Melting point: mp 179°
Derivative Type: Benzoate
Molecular Formula: C35H48O2
Molecular Weight: 500.75
Percent Composition: C 83.95%, H 9.66%, O 6.39%
Properties: Plates or needles, mp 169-171°. [a]D23 -71° (c = 1.1 in CHCl3), [a]546 -88° (CHCl3).
Melting point: mp 169-171°
Optical Rotation: [a]D23 -71° (c = 1.1 in CHCl3); [a]546 -88° (CHCl3)
Derivative Type: 22,23-Dihydro analog
Additional Names: 22,23-Dihydroergosterol
Molecular Formula: C28H46O
Molecular Weight: 398.66
Percent Composition: C 84.36%, H 11.63%, O 4.01%
Literature References: Prepn: A. Windhaus, R. Langer, Ann. 508, 105 (1934); D. H. R. Barton et al., J. Chem. Soc. Perkin Trans. 1 1976, 821; D. J. Curry et al., ibid. 1977, 822. uv irradiation gives vitamin D4, q.v.
Properties: Solvated needles from ethyl acetate + methanol, mp 152-153° (dried). [a]D19 -109° (CHCl3) (Windhaus); also reported as needles from chloroform-methanol, mp 128-130°. [a]D19 -121° (c = 0.1). uv max: 262, 272, 282, 294 nm (e 8000, 11200, 11800, 6800) (Barton).
Melting point: mp 152-153° (dried); mp 128-130°
Optical Rotation: [a]D19 -109° (CHCl3) (Windhaus); [a]D19 -121° (c = 0.1)
Absorption maximum: uv max: 262, 272, 282, 294 nm (e 8000, 11200, 11800, 6800) (Barton)
Derivative Type: 22,23-Dihydro analog acetate
Molecular Formula: C30H48O2
Molecular Weight: 440.70
Percent Composition: C 81.76%, H 10.98%, O 7.26%
Properties: mp 157-158°. [a]D17 -75° (c = 2.1 in CHCl3).
Melting point: mp 157-158°
Optical Rotation: [a]D17 -75° (c = 2.1 in CHCl3)
Therap-Cat: Vitamin (antirachitic).
Keywords: Vitamin/Vitamin Source; Vitamin D.
Ergotamine Ergotaminine Ergothioneine Ergotinine Eriochrome?Black T

Ergosterol structure.svg
CAS number 57-87-4 YesY
PubChem 444679
ChemSpider 392539 YesY
EC number 200-352-7
MeSH Ergosterol
ChEBI CHEBI:16933 YesY
Jmol-3D images Image 1
Molecular formula C28H44O
Molar mass 396.65 g/mol
Melting point 160.0 °C
Boiling point 250.0 °C
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ergosterol (ergosta-5,7,22-trien-3β-ol) is a sterol found in fungi, and named for ergot, a common name for the members of the fungal genus Claviceps from which ergosterol was first isolated. Ergosterol does not occur in plant or animal cells. It is a component of yeast and fungal cell membranes, serving the same function cholesterol serves in animal cells.

Ergosterol is occasionally reported analytically to occur in grasses such as rye[1] and alfalfa (including alfalfa sprouts), and in plant flowers such as hops.[2] However, such detection is usually assumed to be detection of fungal growth upon (and sometimes contamination of) the plant, as fungi form an integral part of the grass decay system. This ergosterol assay technique may thus be used to assay grass, grain, and feed systems for fungal content.[3][4]

Since ergosterol is the provitamin of vitamin D2, the ultraviolet (UV) radiation of fungus-bearing grass materials can result in vitamin D2 production,[5] but this is production of a form of vitamin D from fungus ergosterol (much as in UV radiation of yeasts and mushrooms) and is not true vitamin D production by the plant itself from UV light, a process that cannot happen.