ERB-26 is a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

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 a selective

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

of the

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 ...

. It is the

active Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * "Active" (song), a 2024 song by Asake and Travis Scott from Asake's album ''Lungu Boy'' * Active Records, a record label Ships * ''Active'' (ship), several com ...

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

of the

racemic mixture In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...

ERB-79. Whereas ERB-79 shows 484-fold selectivity for the ERβ over the ERα, ERB-26 differs slightly in that it is even more selective, showing greater than 1,000-fold selectivity for

transactivation In the context of gene regulation: transactivation is the increased rate of gene expression triggered either by biological processes or by artificial means, through the expression of an intermediate transactivator protein. In the context of recep ...

of the ERβ relative to the ERα. Its EC₅₀ value for the ERβ is 0.21 nM (4-fold weaker than

estradiol Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible ...

) and for the ERα is 260 nM (10,000-fold weaker than estradiol). It has no

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain. ERB-26 is active in prevention of

prostate cancer Prostate cancer is the neoplasm, uncontrolled growth of cells in the prostate, a gland in the male reproductive system below the bladder. Abnormal growth of the prostate tissue is usually detected through Screening (medicine), screening tests, ...

development in

preclinical In drug development, preclinical development (also termed preclinical studies or nonclinical studies) is a stage of research that begins before clinical trials (testing in humans) and during which important feasibility, iterative testing and dr ...

model A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , . Models can be divided in ...

s. In contrast to ERB-26, the selective ERα agonist ERA-45 induced prostate cancer development in preclinical models when it was given in combination with

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

, whereas testosterone alone did not do so. These findings suggest opposing roles of the ERα and ERβ in the

prostate gland The prostate is an male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemica ...

. The

chemical structure A chemical structure of a molecule is a spatial arrangement of its atoms and their chemical bonds. Its determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target m ...

of ERB-26 does not appear to have been disclosed.

References

Drugs with undisclosed chemical structures Selective ERβ agonists Synthetic estrogens {{Genito-urinary-drug-stub

See also

References