AbstractsChemistry

The term “glycoside” is a general term applied to compounds containing a group combined with a sugar residue through an ether linkage involving the reducing hydroxyl. The non-sugar portion is called agylcone. The sugar portion may consist of residues of any of a number of sugars but glucose is most often present. In this case the glycoside is called a “glucoside” and possess the following general formula:- [formula here]. In general glycosides are colourless crystalline solids with a bitter taste. They are stable to dilute alkali but are hydrolysed by dilute acid or enzymes, the latter often being found in the same plant (if it is a plant gylcoside). The rate and ease of hydrolysis varies widely. In optical activity they are often laevorotatory and their optical rotation remains constant in non-ionising solvents i.e. they do not mutarotate. Since they do not reduce Fehling’s Solution or combine with phenylhydrazine or similar reagents, it is clear that the reducing hydroxyl group on carbon one is the one involved in the glycosidic link.