Glycosides, or sugar ethers, are a complex grouping of aldehydes and alcohols which can be broken down to yield one or more sugars (glycones), plus a non-sugar component (aglycones).
It is important to note that glycosides are not a major classification of phytochemicals, however it is often when a phytochemical is in its glycosidic form that a constituent may have a specific therapeutic action.
The formation of a glycoside is dependent on interaction with Carbon, Sulphur, Nitrogen, or alcohol/phenol components. Given this, glycosides can occur in any of the major phytochemical classifications, because a sugar ether can bind itself to molecules in myriad of ways.
Glycosides are most commonly classified according to the chemical nature of the aglycone, and have vast medicinal applications as they are found in almost every therapeutic class (example: cardiac glycosides or anthraquinone glycosides).
Some glycosidic categories are as follows: