This compound, known as uridine 5'-diphospho-α-D-glucuronic acid (UDP-GlcA), is a vital nucleotide sugar cofactor in mammalian metabolism. It acts as the primary donor of glucuronic acid in glucuronidation reactions catalyzed by UDP-glucuronosyltransferases (UGTs), a key phase II detoxification pathway in the liver and other tissues. UDP-GlcA facilitates the conjugation of endogenous substrates (e.g., bilirubin, steroid hormones) and xenobiotics (e.g., drugs, toxins), enhancing their water solubility for excretion. In biochemical and pharmaceutical research, it is extensively used in enzymatic assays to evaluate UGT activity, isoform specificity, and drug metabolism profiles. Additionally, it plays a role in the biosynthesis of glycosaminoglycans and proteoglycans, contributing to extracellular matrix formation. Its applications include studies on drug-drug interactions, pharmacokinetics, and the development of therapeutics targeting metabolic disorders.