Uronic Acid


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Related to Uronic Acid: hyaluronic acid, Aldonic acid

uronic acid

[yə′rän·ik ′as·əd]
(organic chemistry)
One of the compounds that are similar to sugars, except that the terminal carbon has been oxidized from the alcohol to a carboxyl group; for example, galacturonic acid and glucuronic acid.

Uronic Acid

 

any of the organic substances that are related to monosaccharides but that are distinguished from the latter by having a carboxyl group (—COOH) in place of the—CH2OH radical. The difference is illustrated by the following structural formulas:

Uronic acids are crystalline or amorphous substances that are nonvolatile, relatively high-melting, and readily soluble in water and polar solvents. Chemically, they possess the properties of both monosaccharides (mutarotation, oxidation, reduction, ability to form glycosides) and hydroxy acids (formulation of esters and lactones). Uronic acids occur in nature with six carbon atoms, and their names are based on the corresponding hexose. The name “glucuronic acid,” for example, derives from “glucose.”

Uronic acids are constituents of many important biopolymers of plant and animal origin. D-glucuronic acid is a component of hemicelluloses, gums, hyaluronic acid, and heparin; D-galacturonic acid, which is the monomeric unit of pectic substances, is a constituent of certain bacterial polysaccharides. The biosynthesis of uronic acids occurs with the participation of nucleoside diphosphate sugars and involves the oxidation of the—CH2OH radical of the monosaccharide. In animals, D-glucuronic acid (found in the blood and urine) removes toxic substances by forming glycosides; the acid is also the starting material in the biosynthesis of absorbic acid.

REFERENCE

Khimiia uglevodov. Moscow, 1967. Chapter 10.

L. V. BAKINOVSKII

References in periodicals archive ?
Then the contents of monosaccharides and uronic acids in the fractions were determined.
Lignin and uronic acid contents in wood and eucalyptus cellulose pulp.
sonchifolia on the Lung collagen hydroxyproline, hexosamine and uronic acid levels
Total non-cellulosic polysaccharides (NCP) = rhamnose + fucose + arabinose + xylose + mannose + galactose + glucose + uronic acids
This may be attributed to two different uronic acid content of alginate.
The CWP was calculated as the sum of arabinose, fucose, galactose, glucose, mannose, rhamnose, xylose, and total uronic acid residues.
Only uronic acid moieties showed some tendency to degradation with reduced ratios on pulping.
This sterile nonwoven is based on a uronic acid alginate/carboxy methyl cellulose fiber and works by forming a conformable hydrophilic gel on the wound surface.
Thus, the assay should accurately account for uronic acid content, and it should not be significantly affected by degree of polymerization.