glycosides

Introduction
? Definition: ?Glycosides are non-reducing organic compounds that on hydrolysis with acids, alkalis or enzymes yield:
? A sugar part (or glycone, formed of one or more sugar units).
? A non-sugar part (or aglycone, also called genin).
Classification: ? Atom from the aglycone involved in the glycosidic linkage: ? Aglycone- O- Sugar O-glycosides ? Aglycone- C- Sugar C-glycosides ? Aglycone- S- Sugar S-glycosides ? Aglycone- N- Sugar N-glycosides ? Number of sugars: ? One sugar monosides e.g. Salicin. ? Two sugar Biosides e.g. Diosmin. ? Three sugars Triosides e.g. Digoxin.
? Nature of the glycoside: ? Primary glycosides: Originally present in the plant e.g. Purpurea A ? Secondary glycosides: Resulted from removal of one sugar from the primary glycosides e.g. Digitoxin
? Botanical source: example: ? Digitalis glycosides ? Senna glycosides. ? Therapeutic use: example: ? Analgesic glycosides. ? Purgative glycosides. ? Cardiac glycosides. ? Chemical nature of the aglycone: example: ? Flavone glycosides. ? Steroidal glycosides. ? Aldehydic glycosides.