Estrogen glucuronide (EG)

Estrogen glucuronides are a class of phase II metabolites formed by the conjugation of glucuronic acid to estrogenic steroids, such as estradiol, estrone, and estriol. This metabolic process is mediated by various UDP-glucuronosyltransferase (UGT) enzymes, primarily within the liver, kidney, and gastrointestinal tract, to increase the water solubility of these lipophilic hormones and facilitate their excretion through urine and bile (Source: PubChem, PubMed PMID: 21551255). While they are not therapeutic targets in the traditional sense of being receptors or enzymes, they serve as essential biomarkers for assessing estrogen levels, monitoring the menstrual cycle, and evaluating the risk of hormone-sensitive conditions like breast and endometrial cancers (Source: PubMed PMID: 11511553). A significant pharmacological aspect of estrogen glucuronides is their role in enterohepatic circulation, where they can be deconjugated back into active estrogens by bacterial beta-glucuronidase in the gut, potentially prolonging the biological half-life of the hormone (Source: Wikipedia). Consequently, drugs that inhibit UGT enzymes or gut beta-glucuronidases can significantly alter systemic estrogen exposure and therapeutic outcomes.

Other names

Estrone glucuronideEstradiol glucuronideEstriol glucuronideEstrogen conjugateE1GE2GE3G

Metabolic conjugation of estrogens by UDP-glucuronosyltransferases (UGTs) to facilitate renal and biliary excretion.