digitoxose

Digitoxose is a deoxypentose sugar that occurs as part of the sugar moiety in certain cardiac glycosides produced by Digitalis species. It is best known for its role in digitoxin and related compounds, where digitoxose residues are linked to the aglycone plus other sugar units to form a short oligosaccharide tail. As a deoxy sugar, digitoxose has one or more missing hydroxy groups relative to a standard pentose, and it can exist in different ring forms (pyranose or furanose) with configurations that vary by natural source.

In the cardiac glycosides, the sugar portion, including digitoxose, contributes to the pharmacokinetic properties, including solubility, tissue distribution, and enzymatic stability, and can influence binding to biological targets such as Na+/K+-ATPase. The exact sugar sequence and linkage differ among glycosides, but digitoxose is a characteristic component in several digitalis-derived compounds.

Analytically, digitoxose is identified by hydrolysis of the glycoside to release the sugar, followed by chromatographic and spectroscopic methods (e.g., TLC, GC-MS or NMR) to determine sugar identity and stereochemistry.

See also: Cardiac glycoside, digitoxin, digoxin, glycoside carbohydrate moieties.