Cholesterin Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R10:Entzündlich.
R48/20/22:Gesundheitssch?dlich: Gefahr ernster Gesundheitssch?den bei l?ngerer Exposition durch Einatmen und durch Verschlucken.
R40:Verdacht auf krebserzeugende Wirkung.
R38:Reizt die Haut.
R22:Gesundheitssch?dlich beim Verschlucken.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-S?tze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S22:Staub nicht einatmen.
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Beschreibung
Cholesterol is a soft waxy substance that is a steroidal alcohol or sterol. It is the most abundant
steroid in the human body and is a component of every cell. Cholesterol is essential to life
and most animals and many plants contain this compound. Cholesterol biosynthesis occurs
primarily in the liver, but it may be produced in other organs. A number of other substances
are synthesized from cholesterol including vitamin D, steroid hormones (including the sex
hormones), and bile salts. Cholesterol resides mainly in cell membranes.
Humans produce about 1 gram of cholesterol daily in the liver. Dietary cholesterol is consumed
through food. High cholesterol foods are associated with saturated fats and trans-fatty
acids (commonly called trans fats). Dietary cholesterol comes from animal products (plants
contain minute amounts of cholesterol) such as meats and dairy products.
Chemische Eigenschaften
Cholesterol occurs as white or faintly yellow, almost odorless,
pearly leaflets, needles, powder, or granules. On prolonged
exposure to light and air, cholesterol acquires a yellow to tan color.
History
Cholesterol was discovered in 1769 by Poulletier dela Salle (1719–1787), who isolated
the compound from bile and gallstones. It was rediscovered by Michel Eugène Chevreul
(1786–1889) in 1815 and named cholesterine. The name comes from the Greek words khole
meaning bile and steros meaning solid or stiff . The “ine” ending was later changed to “ol” to
designate it as an alcohol.
Verwenden
Cholesterol is a major component of all biological membranes; ~25% of total brain lipid is Cholesterol. Cholesterol is the principal sterol of the higher animals. Cholesterol was found in all body tis
sues, especial in the brain, spinal cord, and in animal fats or oils. Cholesterol is the main constituent of gallstones.
Definition
cholesterol: A sterol occurringwidely in animal tissues and also insome higher plants and algae. It canexist as a free sterol or esterified witha long-chain fatty acid. Cholesterol isabsorbed through the intestine ormanufactured in the liver. It servesprincipally as a constituent of bloodplasma lipoproteins and of thelipid–protein complexes that formcell membranes. It is also importantas a precursor of various steroids, especiallythe bile acids, sex hormones,and adrenocorticoid hormones. Thederivative 7-dehydrocholesterol isconverted to vitamin D
3 by the actionof sunlight on skin. Increased levelsof dietary and blood cholesterol havebeen associated with atherosclerosis,a condition in which lipids accumulateon the inner walls of arteries andeventually obstruct blood flow.
Vorbereitung Methode
The commercial material is normally obtained from the spinal cord
of cattle by extraction with petroleum ethers, but it may also be
obtained from wool fat. Purification is normally accomplished by
repeated bromination. Cholesterol may also be produced by entirely
synthetic means.
Cholesterol produced from animal organs will always contain
cholestanol and other saturated sterols.
Allgemeine Beschreibung
Cholesterol is a minor sterol present in plants. It is majorly associated with the plant membranes and is a constituent of leaf surface lipids.
Hazard
Questionable carcinogen.
Pharmazeutische Anwendungen
Cholesterol is used in cosmetics and topical pharmaceutical
formulations at concentrations of 0.3–5.0% w/w as an emulsifying
agent. It imparts water-absorbing power to an ointment and has
emollient activity.
Cholesterol also has a physiological role. It is the major sterol of
the higher animals, and it is found in all body tissues, especially in
the brain and spinal cord. It is also the main constituent of
gallstones.
Sicherheitsprofil
Experimental
teratogenic and reproductive effects.
Questionable carcinogen with experimental
carcinogenic and tumorigenic data. Mutation
data reported. Used in pharmaceutical and
dermal preparations as an emulsifying agent.
When heated to decomposition it emits
acrid smoke and irritating fumes.
Sicherheit(Safety)
Cholesterol is generally regarded as an essentially nontoxic and
nonirritant material at the levels employed as an excipient. It has,
however, exhibited experimental teratogenic and reproductive
effects, and mutation data have been reported.
Cholesterol is often derived from animal sources and this must
be done in accordance with the regulations for human consumption.
The risk of bovine spongiform encephalopathy (BSE)
contamination has caused some concern over the use of animalderived
cholesterol in pharmaceutical products. However, synthetic
methods of cholesterol manufacture have been developed.
Lager
Cholesterol is stable and should be stored in a well-closed container,
protected from light.
l?uterung methode
Crystallise cholesterol from ethyl acetate, EtOH or isopropyl ether/MeOH. [Hiromitsu & Kevan J Am Chem Soc 109 4501 1987.] For extensive details of purification through the dibromide, see Fieser [J Am Chem Soc 75 5421 1953] and Schwenk and Werthessen [Arch Biochem Biophys 40 334 1952], and by repeated crystallisation from acetic acid; see Fieser [J Am Chem Soc 75 4395 1953]. Like many sterols, cholesterol gives colour reactions with conc H2SO4: When cholesterol is dissolved in a small volume of CHCl3 and mixed with conc H2SO4, the colour of the organic layer becomes crimson, then changes to purple and on further standing in air it turns to blue, then green and finally yellow. The H2SO4 layer develops a green fluorescence. [Beilstein 6 III 2607, 6 IV 4000.]
Inkompatibilit?ten
Cholesterol is precipitated by digitonin.
Regulatory Status
Included in the FDA Inactive Ingredients Database (injections;
ophthalmic, topical, and vaginal preparations).
Included in nonparenteral medicines licensed in the UK. Included
in the Canadian List of Acceptable Non-medicinal Ingredients.
Cholesterin Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
