Glycone

Glycone is the sugar-containing portion of a glycoside molecule. In glycosides, the molecule consists of a glycone, the glycosyl or sugar moiety, linked by a glycosidic bond to an aglycone, the non-sugar portion. The glycone is typically a monosaccharide such as glucose, galactose, rhamnose, or arabinose, or a short oligosaccharide. The identity and configuration of the glycone influence the solubility, stability, and biological activity of the glycoside, as well as its enzymatic hydrolysis and absorption.

Glycosides are characterized by the attachment of a glycone to a wide range of aglycones, including steroids, flavonoids, phenolics, and other aromatic or aliphatic structures. In many plant and animal compounds, the glycone determines properties such as water solubility and taste, while the aglycone largely determines the pharmacological or sensory activity. For example, cardiac glycosides typically have a sugar-rich glycone attached to a steroid aglycone.

Biological processing of glycosides involves hydrolysis of the glycosidic bond, either by acid or by glycosidase enzymes, to release the glycone and the aglycone. This hydrolysis is important for activating, detoxifying, or enabling the biological effects of the compound, and it can influence distribution, metabolism, and excretion. The glycone portion thus plays a central role in the chemistry, biology, and pharmacology of glycosides.