(glycoside) Any compound in which a sugar group is covalently bonded through its anomeric carbon to another group via an O-glycosidic bond or an S-glycosidic bond; glycosides involving the latter are also called thioglycosides. However, substances containing N-glycosidic bonds, where the anomeric carbon is bound to some other group via a nitrogen atom, are called glycosylamines; the term "N-glycoside" is considered a misnomer by IUPAC and is discouraged. Furthermore, the sugar group needs to be bonded to a non-sugar for the molecule to qualify as a glycoside, thus excluding the polysaccharides. The sugar group in glycosides is known as the glycone, which can be a single sugar group (monosaccharide) or several sugar groups (oligosaccharide); the non-sugar group is known as the aglycone or genin.

Group of substances obtained from species of Digitalis, Strophanthus, and other plants that contain specific steroid glycosides or their semisynthetic derivatives and used in congestive heart failure; they increase the force of cardiac contraction without significantly affecting other parameters, but are very toxic at larger doses; their mechanism of action usually involves inhibition of the Na(+)-K(+)-exchanging ATPase and they are often used in cell biological studies for that purpose.

Cyclopentanophenanthrenes with a 5- or 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. Plants they come from have long been used in congestive heart failure. They increase the force of cardiac contraction without significantly affecting other parameters, but are very toxic at larger doses. Their mechanism of action usually involves inhibition of the NA(+)-K(+)-EXCHANGING ATPASE and they are often used in cell biological studies for that purpose.