Phosphatidylcholines

Phosphatidylcholines (PC) 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 soybeans, from which they are mechanically 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.

Structure and Synthesis

Phosphatidylcholines are structurally composed of a choline molecule attached to a phosphoric acid, which in turn is attached to a diglyceride. The synthesis of phosphatidylcholine in the liver involves the addition of choline to CDP-Diacylglycerol by the enzyme CTP:phosphocholine cytidylyltransferase.

Function

Phosphatidylcholines play a crucial role in lipid metabolism because they are a major source of the bioactive molecules diacylglycerol and arachidonic acid. They are also important components of the pulmonary surfactant and are used in the lungs to facilitate the exchange of oxygen and carbon dioxide.

Health Implications

Phosphatidylcholines have been associated with a number of health benefits. They are used in the treatment of hepatitis, eczema, gallbladder disease, circulatory disorders, and high cholesterol. They are also used to improve the effectiveness of kidney dialysis and to boost the immune system.

See Also

• Lipid
• Phospholipid
• Choline
• Lecithin