Oligosaccharides are compounds from sugars class, in their molecular structure entering a small number of units of monosaccharides, identical or different, linked together by glycosidic links. Following the units of monosaccharides components, we meet di-, tri-, tetrasaccharides.
Is obtained by removing a molecule of water between two monosaccharides. In nature the most common disaccharides are formed hexoze (glucose, galactose, fructose). They are known two types of disaccharides: reducing disaccharides and non-reducing disaccharides.
Compounds are solid, with good solubility in water, when heated, decomposes,
They have all the properties characteristic of monosaccharides.
1. Maltose is found in small quantities in plants, malt germ, in yeast, in some animal secretions. Maltose is the structural unit of starch. Obtained by hydrolysis of starch in the presence of mineral acids or by enzymatic path, under the action of the enzyme amylase.
2. Sucrose- is the structural unit of cellulose
3. Lactose is found in mammalian milk.
Oligosaccharides are sugars having two or more monosaccharide units. The glycosidic links between the adjacent atoms of their molecules enabling this group of molecules possible.
Glucose and fructose are "single" sugars or monosaccharides. A disaccharide is formed if these two monosaccharides are linked together by an O –glycosidic linkage.
Disaccharides are also termed as ‘double sugars’. Maltose, sucrose and lactose are well known disaccharides. Maltose is formed by the linkage of two glucose molecules whereas sucrose is formed from glucose and fructose.
Lactose is a sugar in milk and is formed by the beta -1, 4 -glycosidic linkage between the two simple sugars glucose and galactose.