Question

Describe the differences between anomers and their mutarotation. How is the anomeric form of the original monosaccharides related to the type of glycosidic bond formed when a disaccharide is produced?

Answer 1

Differences between anomers and their mutarotation:-

Mutarotation is the change in the optical rotation because of the change in the equilibrium between two anomers, when the corresponding stereocenters interconvert. Cyclic sugars show mutarotation as α and β anomeric forms interconvert. The optical rotation of the solution depends on the optical rotation of each anomer and their ratio in the solution. The observed mutarotation of the sample is the weighted sum of the optical rotation of each anomer weighted by the amount of that anomer present. The pure anomer can be isolated by crystallization. When the pure anomers are dissolved in water they undergo mutarotation, the process by which they return to an equlibrium mixture os anomer.

On the other hand a glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some compound such as an alcohol. A substance containing a glycosidic bond is a glycoside which is given as below.