glykosidisidos

Glykosidisidos, known in English as glycosides, are a broad class of natural products in which a sugar moiety (the glycone) is covalently bound to a non-sugar moiety (the aglycone) by a glycosidic linkage. The bond is most commonly O-glycosidic, but glycosides can also feature carbon–carbon (C-glycosides) bonds or, less commonly, N- or S-glycosidic linkages. The glycone is usually a monosaccharide such as glucose, but a variety of sugars occur.

Glycosides are widespread in plants and other organisms, where they often serve as storage forms of bioactive compounds, contribute to defense, alter flavor or color, or modulate the solubility and transport of aglycones. They are biosynthesized by glycosyltransferase enzymes that attach sugar units to diverse aglycones, including terpenoids, steroids, flavonoids, and cyanogenic compounds. In many cases, the biological activity resides in the aglycone, which is released through hydrolysis by glycosidases or acidic conditions.

Examples include salicin, a phenylglucoside from willow bark, which yields salicylic acid; digoxin and other cardiac glycosides, which combine sugar chains with cardioactive aglycones; and amygdalin, a cyanogenic glycoside that can release hydrogen cyanide upon hydrolysis. Glycosides also serve in pharmaceuticals and flavors (for example, vanilla and other plant-derived glycosides) and are subject to analytical and biotechnological study for their biosynthesis, metabolism, and therapeutic potential.