A galactoside is a glycoside containing galactose. The H of the OH group on carbon-1 of galactose is replaced by an organic moiety.
Depending on whether the glycosidic bond lies "above" or "below" the plane of the galactose molecule, galactosides are classified as α-galactosides or β-galactosides.
A β-galactoside is a type of galactoside in which the glycosidic bond lies above the plane of the galactose residue. The most commonly recognized and used β-galactoside in biochemistry is lactose. However, other chemicals, such as ONPG, are known, but these are typically synthesized for biochemical assays. An enzyme that breaks the β-galactoside bond is called a β-galactosidase.
Glycosides
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Bond |
- O-glycosidic bond
- N-glycosidic bond
- S-glycosidic bond
- C-glycosidic bond
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Geometry |
- α-Glycoside
- β-Glycoside
- 1,4-Glycoside
- 1,6-Glycoside
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Glycone |
- Fructoside
- Galactoside
- Glucoside
- Glucuronide
- Rhamnoside
- Riboside
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Aglycone |
- Alcoholic glycoside
- Anthraquinone glycoside
- Cardiac glycoside
- Bufadienolide
- Cardenolide
- Coumarin glycoside
- Cyanogenic glycoside
- Flavonoid glycoside
- Glycosylamine
- Phenolic glycoside
- Saponin
- Steviol glycoside
- Thioglycoside
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- biochemical families: proteins (amino acids/intermediates)
- nucleic acids (constituents/intermediates)
- carbohydrates (glycoproteins, alcohols, glycosides)
- lipids (fatty acids/intermediates, phospholipids, steroids, sphingolipids, eicosanoids)
- tetrapyrroles/intermediates
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