Before we begin this article, it is important to draw your attention to the fact that many people often confuse glycosides with glucosides. While all glycosides are not glucosides, all glucosides are essentially glycosides. In fact, according to chemistry, glycosides are basically elements bound to a sugar, while in a glucoside, the sugar is actually glucose. Glycosides are soluble in water and alcohol.
In other words, glycosides are basically molecules wherein a sugar is attached to a non-carbohydrate element, generally a minor natural molecule. Glycosides have several important functions in all living organisms. A number of plants stock up compounds in the form of dormant glycosides. These chemicals may be set in motion by certain enzymes by means of hydrolysis that results in the sugar portion to be detached. The activation of these chemicals by the enzymes make them accessible for utilization. A number of such glycosides enclosed by the plants are of therapeutic value. However, in the case of animals and this includes humans, often venoms are attached to sugar molecules as a portion of their abolition from the body.
Precisely speaking, every molecule wherein a sugar group is attached by means of its anomeric carbon (C-1 carbon) to another group through an O-glycosidic attachment or an S-glycosidic link is called a glycoside. In fact, glycosides in which a sugar group is bound to another by means of an S-glycosidic attachment are also known as thioglycosides. In such cases, the sugar group is subsequently identified as glycone, while the non-sugar group is recognized as the genin or aglycone element of the glycoside. In fact, the glycone may comprise a solitary sugar group called monosaccharide or a number of sugar groups known as oligosaccharide.
Initially, glycosides were identified as combined acetals, or a molecule having two solitary connected oxygens bound to one carbon atom, that developed from a recurring variety of monosaccharides, in such a manner that there was a connection of a glycosyl group with a non-acyl group. The attachment between the -OR group and the glycosyl group is known as a glycosidic bond.
In glycosides that appear in nature, the inherent carbonate is expressed as the glycone, while the amalgam ROH, from which the carbonate reside is derived or split, is known as the aglycone or aglycon.
It is possible to isolate the glycone and aglycone segments of glycosides through the chemical process known as hydrolysis conducted in the presence of acid. In addition, several enzymes are also capable of forming as well as disintegrating the glycosidic attachments. While glycoside hydrolases are the most important enzymes that are effective in breaking the glycosidic bonds, glycosyltransferases are the key synthetic enzymes in nature that perform the task equally well. Transformed enzymes called glycosynthases have been developed so that they can materialize glycosidic attachments in exceptional yield.
In addition, there are several other effective chemical means by which glycosidic bonds can be developed artificially. Fischer glycosidation denotes the artificial process of amalgamation of glycosides by means of a reaction of unprotected monosaccharides with alcohols, generally in the solvent form, in the presence of a potent acid catalyst. On the other hand, the Koenigs-Knorr reaction involves the compression or condensation of glycosyl halides together with alcohols in the presence of metal salts like silver carbonate or mercuric oxide.
Glycosides may be categorized by different methods or according to different headings. For instance, glycosides may be classified according to the glycone, the nature of glycosidic bond as well as the aglycone.
