Dgalacturonic

D-galacturonic acid is a uronic acid, the oxidized form of D-galactose in which the primary alcohol at carbon 6 is converted to a carboxyl group. It is typically encountered as the D-enantiomer and is also referred to as D-galacturonate.

In nature, D-galacturonic acid is a major component of pectin, a family of plant polysaccharides that contribute to cell-wall structure. The backbone of pectin is rich in polygalacturonic acid units linked by α-1,4 glycosidic bonds. It is abundant in the pectin of citrus fruits and apples and is often methyl-esterified at the carboxyl groups.

Biosynthesis and metabolism: In plants, galacturonic acid units are incorporated into pectin during cell-wall biosynthesis, with possible further modifications such as methylation or acetylation. In humans, there is no endogenous synthesis of galacturonic acid; dietary D-galacturonate largely arises from microbial degradation of pectin in the gut and is not a major energy source.

Chemical properties and forms: As a carboxylic acid, D-galacturonic acid is acidic and forms salts such as sodium galacturonate. In solution it can adopt ring forms (pyranose) and exists as a mixture of anomeric forms. It is commonly studied as the monomeric unit of pectins and as a substrate in uronic-acid metabolism research.

Applications: D-galacturonic acid serves as a building block of pectin-based materials and is used in academic research as a substrate to study uronic-acid biosynthesis and metabolism. It can also be produced industrially from pectin-rich biomass.