Stilbestrol, or stilboestrol, also known as 4,4'-dihydroxystilbene or 4,4'-stilbenediol, is a

stilbenoid Stilbenoids are hydroxylated derivatives of stilbene. They have a C6–C2–C6 structure. In biochemical terms, they belong to the family of phenylpropanoids and share most of their biosynthesis pathway with Chalconoid, chalcones. Most stilbenoids ...

nonsteroidal estrogen A nonsteroidal estrogen is an estrogen with a nonsteroidal chemical structure. The most well-known example is the stilbestrol estrogen diethylstilbestrol (DES). Although nonsteroidal estrogens formerly had an important place in medicine, they ha ...

and the

parent compound In chemistry, a parent structure is the structure of an unadorned ion or molecule from which derivatives can be visualized. Parent structures underpin systematic nomenclature and facilitate classification. Fundamental parent structures have one ...

of a group of more potent nonsteroidal estrogen

derivative In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...

s that includes, most notably,

diethylstilbestrol Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with ...

(DES). The term "stilbestrol" is often used incorrectly to refer to DES, but they are not the same compound. Stilbestrol itself is an active estrogen but is less potent than DES and other derivatives.

Stilbestrol derivatives

The stilbestrol estrogenic drugs include the following: *

Acefluranol Acefluranol (developmental code name BX-591), also known as 2,3-bis(3,4-diacetoxy-5-fluorophenyl)pentane, is a nonsteroidal antiestrogen of the stilbestrol group that was never marketed. See also * Bifluranol Bifluranol (, ; brand name Prost ...

(an antiestrogen) *

Benzestrol Benzestrol (, ) (brand names Chemestrogen, Ocestrol, Octestrol, Octoestrol, Octofollin) is a synthetic nonsteroidal estrogen of the stilbestrol group which was formerly used medically but has since been discontinued. The stilbestrol estrogens, ...

(''technically'' not a stilbestrol derivative due to its elongated central chain, but a very close analogue and grouped with the stilbestrol estrogens in any case) *

Bifluranol Bifluranol (, ; brand name Prostarex; former developmental code name BX-341) is a synthetic nonsteroidal estrogen of the stilbestrol group related to diethylstilbestrol that has been used as an antiandrogen in the United Kingdom in the treatment ...

Dienestrol Dienestrol (, ) (brand names Dienoestrol, Denestrolin, Dienol and many others), also known as dienoestrol (), is a synthetic nonsteroidal estrogen medication of the stilbestrol group which is or was used to treat menopausal symptoms in the Unit ...

** Dienestrol acetate *

Diethylstilbestrol Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with ...

(commonly, but erroneously shortened to simply “stilbestrol”) ** Diethylstilbestrol diacetate **

Diethylstilbestrol dilaurate Diethylstilbestrol dilaurate (brand name Acnestrol-Lotion) is a synthetic, nonsteroidal estrogen of the stilbestrol group and an ester of diethylstilbestrol (DES) that was previously marketed but is now no longer available. It was formulated and ...

** Diethylstilbestrol dipalmitate ** Diethylstilbestrol dipropionate ** Diethylstilbestrol disulfate **

Diethylstilbestrol monobenzyl ether Diethylstilbestrol monobenzyl ether (brand names Monozol, Hypantin, Pituitrope), also known as benzelstilbestrol, is a synthetic, nonsteroidal estrogen of the stilbestrol group and an ether of diethylstilbestrol (DES) that is described as a pitui ...

** Dimestrol (dianisylhexene, diethylstilbestrol dimethyl ether, dimethoxydiethylstilbene) **

Fosfestrol Fosfestrol, sold under the brand name Honvan and also known as diethylstilbestrol diphosphate (DESDP), is an estrogen medication which is used in the treatment of prostate cancer in men. It is given by slow intravenous infusion once per day to o ...

(diethylstilbestrol diphosphate) ** Furostilbestrol (diethylstilbestrol difuroate) ** ICI-85966 (diethylstilbestrol bis i(2-chloroethyl)carbamate) ** Mestilbol (diethylstilbestrol monomethyl ether) * Dimethylstilbestrol">Mestilbol.html" ;"title="i(2-chloroethyl)carbamate) ** Mestilbol">i(2-chloroethyl)carbamate) ** Mestilbol (diethylstilbestrol monomethyl ether) * Dimethylstilbestrol * Hexestrol (dihydrodiethylstilbestrol) ** Diaethiphenum (hexestrol bis(2-diethylaminoethyl) ether) (a coronary vasodilator) ** Hexestrol diacetate ** Hexestrol dicaprylate ** Hexestrol diphosphate ** Hexestrol dipropionate ** Phenestrol (hexestrol bis -[bis(2-chloroethyl)aminohenylacetate) * Methestrol">is(2-chloroethyl)amino.html" ;"title="-[bis(2-chloroethyl)amino">-[bis(2-chloroethyl)aminohenylacetate) * Methestrol (promethestrol; dimethylhexestrol) ** Methestrol dipropionate (promethestrol dipropionate) * Pentafluranol * Terfluranol Of the stilbestrol estrogens, diethylstilbestrol, hexestrol, and benzestrol are the most well-known.

Mechanism of action

The stilbestrol estrogens bind with high

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Pa ...

to both

ERα Estrogen receptor alpha (ERα), also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1), is one of two main types of estrogen receptor, a nuclear receptor (mainly found as a chromatin-binding protein) that is activated by the se ...

and

ERβ Estrogen receptor beta (ERβ) also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2) is one of two main types of estrogen receptor—a nuclear receptor which is activated by the sex hormone estrogen. In humans ERβ is encoded by t ...

Closely related compounds

Estrogens closely related to the stilbestrols include

paroxypropione Paroxypropione, also known as paraoxypropiophenone, is a synthetic nonsteroidal estrogen which has been used medically as an antigonadotropin in Spain and Italy but appears to no longer be marketed. It was first synthesized in 1902. The antigona ...

(a metabolite of diethylstilbestrol) and the

anise Anise (; '), also called aniseed or rarely anix, is a flowering plant in the family Apiaceae native to the eastern Mediterranean region and Southwest Asia. The flavor and aroma of its seeds have similarities with some other spices and herbs, ...

and

fennel Fennel (''Foeniculum vulgare'') is a flowering plant species in the carrot family. It is a hardy, perennial herb with yellow flowers and feathery leaves. It is indigenous to the shores of the Mediterranean but has become widely naturalized ...

-derived compounds

anol Anol, also known as ''p''-hydroxypropenylbenzene, is a simple phenol that was derived via demethylation from anethole, an estrogenic constituent of anise and fennel, by Sir Charles Dodds in 1937. It was reported to possess extremely potent e ...

, dianol,

anethole Anethole (also known as anise camphor) is an organic compound that is widely used as a flavoring substance. It is a derivative of the aromatic compound allylbenzene and occurs widely in the essential oils of plants. It is in the class of phenylpr ...

dianethole Dianethole is a naturally occurring organic compound that is found in anise and fennel. It is a dimeric polymer of anethole. It has estrogenic activity, and along with anethole and photoanethole, may be responsible for the estrogenic effects of ...

, and

photoanethole Photoanethole is a naturally occurring organic compound that is found in anise and fennel. It has estrogenic activity, and along with anethole and dianethole, may be responsible for the estrogenic effects of anise and fennel. These compounds bear ...

(from which the stilbestrol estrogens were actually originally derived). The

triphenylethylene Triphenylethylene (TPE) is the organic compound with the formula . It is a colorless solid. Synthesis and reactions The compound is prepared in two steps from benzophenone via the intermediacy of 1,2,2-triphenylethanol. Triphenylethylene reacts ...

group of estrogenic drugs that includes triphenylethylene itself,

estrobin Estrobin, also known as α,α-di(''p''-ethoxyphenyl)-β-phenylbromoethylene and commonly abbreviated as DBE, is a synthetic, nonsteroidal estrogen of the triphenylethylene group that was never marketed. Chlorotrianisene, and subsequently clomife ...

chlorotrianisene Chlorotrianisene (CTA), also known as tri-''p''-anisylchloroethylene (TACE) and sold under the brand name Tace among others, is a nonsteroidal estrogen related to diethylstilbestrol (DES) which was previously used in the treatment of menopausal ...

broparestrol Broparestrol () (brand names Acnestrol, Longestrol; former developmental code name LN-107), also known as α-bromo-α,β-diphenyl-β-p-ethylphenylethylene (BDPE), is a synthetic, nonsteroidal selective estrogen receptor modulator (SERM) of the ...

ethamoxytriphetol Ethamoxytriphetol (developmental code name MER-25) is a synthetic nonsteroidal antiestrogen that was studied clinically in the late 1950s and early 1960s but was never marketed. MER-25 was first reported in 1958, and was the first antiestrogen t ...

clomifene Clomifene, also known as clomiphene, is a medication used to treat infertility in women who do not ovulate, including those with polycystic ovary syndrome. It is taken by mouth. Common side effects include pelvic pain and hot flashes. Oth ...

tamoxifen Tamoxifen, sold under the brand name Nolvadex among others, is a selective estrogen receptor modulator used to prevent breast cancer in women and men. It is also being studied for other types of cancer. It has been used for Albright syndrome ...

, and more recently developed derivatives is also very closely related structurally to the stilbestrols.

Resveratrol Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol or polyphenol and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacterium, ba ...

is a stilbenoid with estrogenic properties that is not technically a stilbestrol derivative (it is 3,4',5-stilbenetriol).

Occupational exposure

Occupational exposure to stilbestrol has resulted in

gynaecomastia Gynecomastia (also spelled gynaecomastia) is the non-cancerous enlargement of one or both breasts in men due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse (10 Novemb ...

in workers.

References

{{Stilbenes Stilbenoids Synthetic estrogens