Estrone glucuronide

Estrone glucuronide, or estrone-3-D-glucuronide, is a conjugated metabolite of estrone.^[1] It is formed from estrone in the liver by UDP-glucuronyltransferase via attachment of glucuronic acid and is eventually excreted in the urine by the kidneys.^[1] It has much higher water solubility than does estrone.^[1] Glucuronides are the most abundant estrogen conjugates and estrone glucuronide is the dominant metabolite of estradiol.^[1]

Estrone glucuronide

Names
IUPAC name 17-Oxoestra-1,3,5(10)-trien-3-yl β-D-glucopyranosiduronic acid
Systematic IUPAC name (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-{[(3aS,3bR,9bS,11aS)-11a-methyl-1-oxo-2,3,3a,3b,4,5,9b,10,11,11a-decahydro-1H-cyclopenta[a]phenanthren-7-yl]oxy}oxane-2-carboxylic acid
Other names Estrone 3-glucuronide; Estrone 3-D-glucuronide; Estra-1,3,5(10)-triene-3-ol-17-one 3-D-glucuronoside
Identifiers
CAS Number	2479-90-5
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL1232444
ChemSpider	103124
KEGG	C11133
PubChem CID	115255
UNII	933Q277TO2
CompTox Dashboard (EPA)	DTXSID20891497
InChI InChI=1S/C24H30O8/c1-24-9-8-14-13-5-3-12(10-11(13)2-4-15(14)16(24)6-7-17(24)25)31-23-20(28)18(26)19(27)21(32-23)22(29)30/h3,5,10,14-16,18-21,23,26-28H,2,4,6-9H2,1H3,(H,29,30)/t14-,15-,16+,18+,19+,20-,21+,23-,24+/m1/s1 Key: FJAZVHYPASAQKM-JBAURARKSA-N
SMILES C[C@]12CC[C@H]3[C@H]([C@@H]1CCC2=O)CCC4=C3C=CC(=C4)O[C@H]5[C@@H]([C@H]([C@@H]([C@H](O5)C(=O)O)O)O)O
Properties
Chemical formula	C24H30O8
Molar mass	446.496 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

When exogenous estradiol is administered orally, it is subject to extensive first-pass metabolism (95%) in the intestines and liver.^[2][3] A single administered dose of estradiol is absorbed 15% as estrone, 25% as estrone sulfate, 25% as estradiol glucuronide, and 25% as estrone glucuronide.^[2] Formation of estrogen glucuronide conjugates is particularly important with oral estradiol as the percentage of estrogen glucuronide conjugates in circulation is much higher with oral ingestion than with parenteral estradiol.^[2] Estrone glucuronide can be reconverted back into estradiol, and a large circulating pool of estrogen glucuronide and sulfate conjugates serves as a long-lasting reservoir of estradiol that effectively extends its terminal half-life of oral estradiol.^[2][3] In demonstration of the importance of first-pass metabolism and the estrogen conjugate reservoir in the pharmacokinetics of estradiol,^[2] the terminal half-life of oral estradiol is 13 to 20 hours^[4] whereas with intravenous injection its terminal half-life is only about 1 to 2 hours.^[5]

• v
• t
• e

Affinities and estrogenic potencies of estrogen esters and ethers at the estrogen receptors

Estrogen	Other names	RBATooltip Relative binding affinity (%)a	REP (%)b
		ER	ERα	ERβ
Estradiol	E2	100	100	100
Estradiol 3-sulfate	E2S; E2-3S	?	0.02	0.04
Estradiol 3-glucuronide	E2-3G	?	0.02	0.09
Estradiol 17β-glucuronide	E2-17G	?	0.002	0.0002
Estradiol benzoate	EB; Estradiol 3-benzoate	10	1.1	0.52
Estradiol 17β-acetate	E2-17A	31–45	24	?
Estradiol diacetate	EDA; Estradiol 3,17β-diacetate	?	0.79	?
Estradiol propionate	EP; Estradiol 17β-propionate	19–26	2.6	?
Estradiol valerate	EV; Estradiol 17β-valerate	2–11	0.04–21	?
Estradiol cypionate	EC; Estradiol 17β-cypionate	?c	4.0	?
Estradiol palmitate	Estradiol 17β-palmitate	0	?	?
Estradiol stearate	Estradiol 17β-stearate	0	?	?
Estrone	E1; 17-Ketoestradiol	11	5.3–38	14
Estrone sulfate	E1S; Estrone 3-sulfate	2	0.004	0.002
Estrone glucuronide	E1G; Estrone 3-glucuronide	?	<0.001	0.0006
Ethinylestradiol	EE; 17α-Ethynylestradiol	100	17–150	129
Mestranol	EE 3-methyl ether	1	1.3–8.2	0.16
Quinestrol	EE 3-cyclopentyl ether	?	0.37	?
Footnotes: a = Relative binding affinities (RBAs) were determined via in-vitro displacement of labeled estradiol from estrogen receptors (ERs) generally of rodent uterine cytosol. Estrogen esters are variably hydrolyzed into estrogens in these systems (shorter ester chain length -> greater rate of hydrolysis) and the ER RBAs of the esters decrease strongly when hydrolysis is prevented. b = Relative estrogenic potencies (REPs) were calculated from half-maximal effective concentrations (EC50) that were determined via in-vitro β‐galactosidase (β-gal) and green fluorescent protein (GFP) production assays in yeast expressing human ERα and human ERβ. Both mammalian cells and yeast have the capacity to hydrolyze estrogen esters. c = The affinities of estradiol cypionate for the ERs are similar to those of estradiol valerate and estradiol benzoate (figure). Sources: See template page.

v t e Metabolic pathways of estradiol in humans Estradiol Estrone sulfate Estrone glucuronide 2-Hydroxyestrone Estrone 4-Hydroxyestrone 2-Methoxyestrone 16α-Hydroxyestrone 4-Methoxyestrone 17-Epiestriol Estriol 16-Epiestriol 17β-HSD EST STS UGT1A3 UGT1A9 CYP450 CYP450 COMT CYP450 COMT unidentified 17β-HSD unidentified Description: The metabolic pathways involved in the metabolism of estradiol and other natural estrogens (e.g., estrone, estriol) in humans. In addition to the metabolic transformations shown in the diagram, conjugation (e.g., sulfation and glucuronidation) occurs in the case of estradiol and metabolites of estradiol that have one or more available hydroxyl (–OH) groups. Sources: See template page.

See also

• Catechol estrogen
• Estradiol sulfate
• Estriol glucuronide
• Estriol sulfate
• Estrogen conjugate
• Lipoidal estrogen