monosaccharide
Monosaccharides (from Greek '' monos'': single, '' sacchar'': sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built.
They are usually colorless, water- so ...
with a carboxyl group at one end or both ends of its chain.
Main classes of sugar acids include:
* Aldonic acids, in which the
aldehyde group
In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group ...
(−CHO) located at the initial end ( position 1) of an
aldose
An aldose is a monosaccharide (a simple sugar) with a carbon backbone chain with a carbonyl group on the endmost carbon atom, making it an aldehyde, and hydroxyl groups connected to all the other carbon atoms. Aldoses can be distinguished from ...
is oxidized.
* Ulosonic acids, in which the −CH2(OH) group at the initial end of a 2- ketose is oxidized creating an α- ketoacid.
* Uronic acids, in which the −CH2(OH) group at the terminal end of an aldose or ketose is oxidized.
* Aldaric acids, in which both ends (−CHO and −CH2(OH)) of an aldose are oxidized.
Examples
Examples of sugar acids include:
* Aldonic acids
**
Glyceric acid
Glyceric acid is a natural three-carbon sugar acid obtained from the oxidation of glycerol.
CH2OH-CHOH-CH2OH+O2→CH2OH-CHOH-COOH+H2O
Salts and esters of glyceric acid are known as glycerates.
Biochemistry
Several phosphate derivatives of ...
(3C)
**
Xylonic acid
Xylonic acid is a sugar acid that can be obtained by oxidation of the hemiacetal/aldehyde group of xylose
Xylose ( grc, ξύλον, , "wood") is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of ...
(5C)
**
Gluconic acid
Gluconic acid is an organic compound with molecular formula C6H12O7 and condensed structural formula HOCH2(CHOH)4COOH. It is one of the 16 stereoisomers of 2,3,4,5,6-pentahydroxyhexanoic acid.
In aqueous solution at neutral pH, gluconic acid ...
(6C)
**
Ascorbic acid
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...
Ketodeoxyoctulosonic acid
3-Deoxy--''manno''-oct-2-ulosonic acid (ketodeoxyoctonic acid; KDO; IUPAC symbol Kdo) is an ulosonic acid of a 2-ketooctose which is used by bacteria in the synthesis of lipopolysaccharides. The -''manno'' prefix indicates that the four chiral ...
(KDO or 3-deoxy-D- ''manno''-oct-2-ulosonic acid)
* Uronic acids
**
Glucuronic acid
Glucuronic acid (from Greek γλεῦκος "''wine, must''" and οὖρον "''urine''") is a uronic acid that was first isolated from urine (hence the name). It is found in many gums such as gum arabic (c. 18%), xanthan, and kombucha tea ...
(6C)
**
Galacturonic acid
-Galacturonic acid is a sugar acid, an oxidized form of -galactose. It is the main component of pectin, in which it exists as the polymer polygalacturonic acid.Debra Mohnen "Pectin structure and biosynthesis" Current Opinion in Plant Biology 20 ...
(6C)
**
Iduronic acid
-Iduronic acid (IUPAC abbr.: IdoA) is the major uronic acid component of the glycosaminoglycans (GAGs) dermatan sulfate, and heparin. It is also present in heparan sulfate
Heparan sulfate (HS) is a linear polysaccharide found in all animal tiss ...
(6C)
* Aldaric acids
**
Tartaric acid
Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes, but also in bananas, tamarinds, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally ...
(4C)
** ''meso''-Galactaric acid (
Mucic acid
Mucic acid, C6H10O8 or HOOC-(CHOH)4-COOH (also known as galactaric or meso-galactaric acid) is an aldaric acid obtained by nitric acid oxidation of galactose or galactose-containing compounds such as lactose, dulcite, quercite, and most varieti ...
) (6C)
** D-Glucaric acid (
Saccharic acid
Saccharic acid, also called glucaric acid, is a chemical compound with the formula C6H10O8. It is derived by oxidizing a sugar such as glucose with nitric acid.