glucuronato

Glucuronate, also known as D-glucuronate, is the anionic form of glucuronic acid, a six‑carbon uronic acid derived from glucose. At physiological pH it exists mainly as the carboxylate anion. Glucuronate is a central metabolite in the uronic acid pathway and serves as an activated donor (UDP-glucuronate) for glucuronidation reactions that attach glucuronic acid to a wide range of substrates, increasing their water solubility and promoting excretion.

Biosynthesis and metabolism: In mammals, UDP-glucose is oxidized by UDP-glucose dehydrogenase to UDP-glucuronate. This activated sugar donor is used by UDP-glucuronosyltransferases (UGTs) to conjugate glucuronate to drugs, bilirubin, hormones, and other xenobiotics, forming glucuronides that are more readily excreted in urine or bile. Glucuronate residues are also integral components of glycosaminoglycans, such as hyaluronic acid, chondroitin sulfate, and dermatan sulfate, which constitute the extracellular matrix and contribute to tissue structure and charge.

Physiological significance: Glucuronidation represents a major Phase II detoxification pathway, enabling the elimination of a broad spectrum of endogenous and exogenous compounds. The presence of glucuronate residues in glycosaminoglycans supports the hydrated, negatively charged nature of connective tissues and influences cell signaling and matrix interactions.

Occurrence and emphasis: Glucuronate is produced endogenously in the liver and other tissues, and its activated form, UDP-glucuronate, is a central substrate for detoxification and for the biosynthesis of glycosaminoglycans and proteoglycans.