Glycoside

Glycosides are molecules in which a sugar is bound to a non-carbohydrate moiety, usually a small organic molecule. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme hydrolysis, which causes the sugar part to be broken off, making the chemical available for use.

Structure

A glycoside is formed by a sugar (a glycon) and another non-sugar compound (an aglycon) through a glycosidic bond. The glycosidic bond is formed between the hemiacetal or hemiketal group of the sugar and the hydroxyl group of the aglycon.

Classification

Glycosides are classified by the sugar present in the molecule. The common sugar groups include glucose, fructose, and galactose. The non-sugar part of the molecule, the aglycon, can be a simple organic molecule or a complex one such as a steroid or alkaloid.

Biological Importance

Glycosides have a wide range of uses and biological activities. They are found in a variety of plants and are often used in medicine for their therapeutic properties. Some glycosides are used as sweeteners and flavorings in the food industry.

See Also

• Carbohydrate
• Sugar
• Steroid
• Alkaloid

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  Salicin
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  Oleandrin
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  Amygdalin