What does aglycone mean?
An aglycone is the non-sugar portion of a glycoside — the molecular fragment that remains once the sugar component has been split off, typically through hydrolysis. Glycosides consist of a sugar (or several sugars) bonded to another compound, and that other compound is the aglycone, sometimes also called a genin. In natural-product chemistry the distinction matters because the two parts often behave differently: sugars generally make molecules more water-soluble, while the aglycone frequently carries the characteristic biological activity or flavor. For example, many plant flavonoids occur in foods as sugar-bearing glycosides, but researchers often study their aglycones to assess antioxidant effects. The word derives from Greek roots meaning "without sweetness," reflecting the fact that removing the sugar removes the sweet component. It is a specialist term, encountered mainly in chemistry, pharmacy, and nutrition science rather than everyday language.
nounThe non-sugar portion of a glycoside; the compound that remains after the sugar component of a glycoside has been removed by hydrolysis.
- The non-sugar residue of a glycoside, obtained when the sugar component is removed by hydrolysis.
"Hydrolysis of the glycoside released the aglycone, which was then analyzed by mass spectrometry."
"The flavonoid aglycone quercetin lacks the sugar groups found in many of its glycosides."
"Enzymatic hydrolysis of saponins liberates both sugars and their corresponding aglycones."
Regular plural; commonly used when discussing multiple aglycones obtained from hydrolysis or present in a sample.
"The extract contained several flavonoid aglycones identified by HPLC."
Strip the sugar off a glycoside and what's left — the aglycone — is often the part doing the real pharmacological work.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of aglycone
The term comes from Greek elements: the prefix a- meaning "without" combined with glykys, meaning "sweet," so it literally denotes the "non-sweet" part of a glycoside. It entered scientific usage in the nineteenth century as chemists studying plant glycosides needed a name for the residue left after the sugar was removed. It shares the Greek root glykys with related chemical terms such as glucose, glycogen, and glycoside.
How aglycone is actually used
A technical term used almost exclusively in chemistry, biochemistry, pharmacognosy, and food science; it rarely appears outside scientific literature. The spelling "aglycon" (without the final -e) is an accepted variant.
Easily confused with aglycone
A glycoside is the whole molecule including its attached sugar(s), whereas the aglycone is only the non-sugar part left once those sugars are removed.
"Aglycon" is simply a variant spelling of the same word, not a different substance.