D-Galacturonic acid
Overview
 
D-Galacturonic acid is a sugar acid, an oxidized form of D-galactose
Galactose
Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

. It is the main component of pectin
Pectin
Pectin is a structural heteropolysaccharide contained in the primary cell walls of terrestrial plants. It was first isolated and described in 1825 by Henri Braconnot...

, in which it exists as the polymer polygalacturonic acid. It has an aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....

 group at C1 and a carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

 group at C6. Other oxidized forms of D-galactose are D-galactonic acid (carboxylic group at C1) and meso-galactaric acid (mucic acid
Mucic acid
Mucic acid, C6H10O8 or HOOC-4-COOH, is obtained by nitric acid oxidation of galactose or galactose-containing compounds like lactose, dulcite, quercite, and most varieties of gum....

) (carboxylic groups at C1 and C6). It is also a uronic acid
Uronic acid
thumb|300px|The [[Fischer projection]]s of [[glucose]] and [[glucuronic acid]]. Glucose's terminal carbon's hydroxyl group has been oxidized to a [[carboxylic acid]]....

 or hexuronic acid.
 
x
OK