Estriol glucuronide (E3G), or oestriol glucuronide, also known as estriol monoglucuronide, as well as estriol 16α-β-D-glucosiduronic acid, is a

natural Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part ...

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

and the

glucuronic acid Glucuronic acid (GCA, from ) is a uronic acid that was first isolated from urine (hence the name "uronic acid"). It is found in many natural gum, gums such as gum arabic ( 18%), xanthan, and kombucha tea and is important for the metabolism of ...

(β-D-glucopyranuronic acid) conjugate of

estriol Estriol (E3), also spelled oestriol, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estrone. Levels of estriol in women who are not pregnant are almost ...

. It occurs in high concentrations in the

urine Urine is a liquid by-product of metabolism in humans and many other animals. In placental mammals, urine flows from the Kidney (vertebrates), kidneys through the ureters to the urinary bladder and exits the urethra through the penile meatus (mal ...

pregnant Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

women as a reversibly formed

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

. Estriol glucuronide is a

prodrug A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be ...

, and was the major component of

Progynon Conjugated estriol, sold under the brand names Progynon and Emmenin, is an estrogen medication which was previously used for estrogen-type indications such as the treatment of menopausal symptoms in women. The term specifically refers to formula ...

and

Emmenin Conjugated estriol, sold under the brand names Progynon and Emmenin, is an estrogen medication which was previously used for estrogen-type indications such as the treatment of menopausal symptoms in women. The term specifically refers to formula ...

, estrogenic products manufactured from the urine of pregnant women that were introduced in the 1920s and 1930s and were the first orally active estrogens. Emmenin was succeeded by

Premarin Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of th ...

( conjugated equine estrogens), which is sourced from the urine of pregnant mares and was introduced in 1941. Premarin replaced Emmenin because it was easier and less expensive to produce. Estrogen glucuronides can be deglucuronidated into the corresponding free estrogens by β-glucuronidase in tissues that express this

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

, such as the

mammary gland A mammary gland is an exocrine gland that produces milk in humans and other mammals. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primates (for example, human ...

. As a result, estrogen glucuronides have estrogenic activity via conversion into estrogens. The

positional isomer In chemistry, a structural isomer (or constitutional isomer in the IUPAC nomenclature) of a compound is a compound that contains the same number and type of atoms, but with a different connectivity (i.e. arrangement of bonds) between them. The ...

of estriol 16α-glucuronide, estriol 3-glucuronide, also occurs as an endogenous metabolite of estriol, although to a much lower extent in comparison.

References

External links

Metabocard for Estradiol 17-Glucuronide - Human Metabolome Database
Estranes Estriol esters Estrogens Glucuronide esters Hormones of the hypothalamus-pituitary-gonad axis Hormones of the pregnant female Human metabolites Sex hormones {{Genito-urinary-drug-stub

See also

References

External links