Phosphatidylcholine

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Phosphatidylcholines are a class of phospholipids that incorporate choline as a headgroup. They are a major component of biological membranes and can be easily obtained from a variety of readily available sources such as egg yolk or soy beans from which they are mechanically extracted or chemically extracted using hexane. They are also a member of the Lecithin group of yellow-brownish fatty substances occurring in animal and plant tissues.

The name Lecithin was originally defined from Greek lekithos - λεκιθος, (litteraly: egg yolk) by Theodore Nicolas Gobley, a French chemist and pharmacist of the mid XIXth, who applied it to the first phosphatidylcholine in history, the egg yolk lecithin, that he identified in 1847 and finally completely described from a chemical structure point of view in 1874.

Phosphatidylcholine (sometimes abbreviated as PC) is more common on the exoplasmic or outer leaflet of a cell membrane.

Fig 1. 1 example of variant phosphatidylcholine, palmitoyl-oleyl-sn-phosphatidylcholine. .

In general, a phosphatidylcholine is obtained combining a choline head group and glycerophosphoric acid with a variety of fatty acids, one being a saturated fatty acid, in the example here palmitic acid or hexadecanoic acid H3C-(CH2)14-COOH (margaric acid identified by Gobley in egg yolk, or heptadecanoïc acid H3C-(CH2)15-COOH, belongs to that class) and an unsaturated fatty acid, here oleic acid or 9Z-octadecenoic acid as in Gobley's original egg yolk lecithin).

Phosphatidylcholines are such a major component of lecithin, that, in some contexts, the terms are sometimes used as synonyms. However, lecithin extract consists of a mixture of phosphatidylcholine and other compounds. It is also used along with sodium taurocholate for simulating fed- and fasted-state biorelevant media in dissolution studies of highly-lipophilic drugs. Phosphatidylcholine is a major constituent of cell membranes, and also plays a role in membrane-mediated cell signalling.

Phospholipase D catalyzes the hydrolysis of phosphatidylcholine to form phosphatidic acid (PA), releasing the soluble choline headgroup into the cytosol.

Some medical researchers are experimenting with injection lipolysis, using injected phosphatidylcholine to try to break down fat cells, as an alternative to liposuction.

Molecular weight: 760.09 g/mol. (http://www.jenabioscience.com/images/5103fef174/LI-004.pdf)

Contents 1 Health 2 See also 3 Additional images 4 References 5 External links

[edit] Health

Phosphatidylcholine is a vital substance that is in every cell in the human body. At birth and throughout infancy, phosphatidlycholine concentrations are high (as high as 90% of the cell wall), but it is slowly depleted throughout the course of life, and may drop to as low as 10% of the cellular wall in the elderly. As is such, some experts in the fields of health and nutrition have begun to recommend daily supplementation of phosphatidylcholine as a way of slowing down senescence. Phosphatidylcholine can be found in many health food stores either as its own product, or in the much more common product soy-lecithin.

[edit] See also

• CDP choline
• Lysophosphatidylcholine
• Theodore Nicolas Gobley, discover of egg yolk lecithin, the first in history phosphatidylcholine
• Saturated fatty acid
• Unsaturated fatty acid

[edit] Additional images

Membrane lipids

Choline metabolism

Phosphatidate

Choline

[edit] References

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[edit] External links

• MeSH Phosphatidylcholines
• http://www.kvue.com/news/top/stories/110507kvuelipodissolve-mm.1e0189bdb.html

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