Lanosterol

• Lanosterol
• Lanosta -8 ,24 -dien- 3β -ol
• 4,4,14 α -trimethyl- 5α -cholesta -8 ,24 -dien- 3β -ol
• Crypto provider
• IUPAC: (3S,5R,10S,13R,14R,17R)-4,4,10,13,14-Pentamethyl-17-[(2R)-6-methylhept-5-en-2-yl]-2,3,5,6,7,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-ol

White powder

Fixed

140-141 ° C

Template: Infobox chemical / molecular formula search available

Lanosterol (also: lanosterol ) is a naturally occurring chemical compound. Chemically, it is a steroid. It is produced in eukaryotic cells as an intermediate in the biosynthesis of cholesterol (in the plant will be assumed, however, the role for the greater part of cycloartenol ). In larger amounts, it is part of wool wax (Latin adeps lanae, hence the name ) in which it of cholesterol as well as the Lanostanderivaten dihydrolanosterol ( Lanost -8 -en- 3β -ol), agnosterol ( Lanosta -7, 9 (11) ,24- trien- 3β -ol) and Dihydroagnosterin ( Lanosta -7, 9 (11) -dien- 3β -ol) is accompanied.

History

The structure of the Lanosterins was solved with classical methods by a Swiss team led by W. Voser in 1950.

Occurrence and extraction

As an intermediate of cholesterol biosynthesis comes lanosterol in all eukaryotes. Sheep sweat it out with the wool wax, from which it can be obtained in large quantities. The separation of the mixture of other triterpenes is difficult and takes place via fractional crystallization and chromatography of the acetates.

Woodward, the synthesis of lanosterol from cholesterol in more than a dozen steps after his team managed the total synthesis of cholesterol itself.

Biosynthesis

Biological synthesis of Lanosterins performed in a remarkable multiple ring-closure reaction of (S) - squalene -2 ,3 -epoxide, catalyzed by the enzyme lanosterol synthase:

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Reactions

Lanosterol is to enter into various chemical reactions in the situation. As the A ring is rearranged to the five-membered ring under the influence of phosphorus pentachloride; the C8-C9 double bond can not be directly hydrogenated, but shifted in acidic medium after C7 - C8; Another dehydrogenation with selenium dioxide, N- bromosuccinimide or perbenzoic acid yields the 7,9 (11) -diene, which can be further oxidized to give enone or diketone.