An estrogen conjugate is a conjugate of an

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, ...

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal a ...

. They occur naturally in the body as

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, ...

s of estrogens and can be reconverted back into estrogens. They serve as a circulating reservoir for estrogen, particularly in the case of

orally administered Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...

estradiol Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...

. Estrogen conjugates include

sulfate The sulfate or sulphate ion is a polyatomic ion, polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salt (chemistry), ...

and/or

glucuronide A glucuronide, also known as glucuronoside, is any substance produced by linking glucuronic acid to another substance via a glycosidic bond. The glucuronides belong to the glycosides. Glucuronidation, the conversion of chemical compounds to glucur ...

conjugates of

estrone Estrone (E1), also spelled oestrone, 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 estriol. Estrone, as well as the other estrogens, are synthesized ...

, and

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 almos ...

: * Sulfated: **

Estrone 3-sulfate Estrone sulfate, also known as E1S, E1SO4 and estrone 3-sulfate, is a natural, endogenous steroid and an estrogen ester and conjugate. In addition to its role as a natural hormone, estrone sulfate is used as a medication, for instance in menop ...

(E1S) ** Estradiol 3-sulfate (E2S, E2-3S) and estradiol 17β-sulfate (E2-17S) **

Estriol 3-sulfate Estriol sulfate, or estriol 3-sulfate, is a conjugated metabolite of estriol that is present in high quantities during pregnancy. It is formed from estriol in the liver and is eventually excreted in the urine by the kidneys. It has much higher wa ...

(E3S) ** Estradiol 3,17β-disulfate (E2DS) * Glucuronidated: **

Estrone 3-glucuronide Estrone glucuronide, or estrone-3-D-glucuronide, is a conjugated metabolite of estrone. 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 ki ...

(E1-G) ** Estradiol 3-glucuronide (E2-3G) and estradiol 17β-glucuronide (E2-17G) ** Estriol 3-glucuronide (E3-3G),

estriol 16α-glucuronide Estriol glucuronide (E3G), or oestriol glucuronide, also known as estriol monoglucuronide, as well as estriol 16α-β-D-glucosiduronic acid, is a natural, steroidal estrogen and the glucuronic acid (β-D-glucopyranuronic acid) conjugate of estr ...

(E3-16G) * Mixed: ** Estradiol 3-glucuronide 17β-sulfate (E2-3G-17βS) ** Estradiol 3-sulfate 17β-glucuronide (E2-3S-17βG) ** Estriol 3-sulfate 16α-glucuronide (E3-3S-16G) Estrogen conjugates are conjugated at the C3, C16α, and/or C17β positions, where

hydroxyl group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

s are available. Estrogen conjugates have been used as

estrogens, as in estrone sulfate as estropipate (piperazine estrone sulfate) and in

conjugated estrogens 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 ...

(Premarin) and conjugated estriol (Progynon, Emmenin).

References

{{Estrogen receptor modulators Estranes Estrogens Human metabolites Steroid hormones

See also

References