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17β-Dihydroequilenin

17β-Dihydroequilenin
17β-Dihydroequilenin.svg
Clinical data
Other namesβ-Dihydroequilenin; Δ6,8-17β-Estradiol; 6,8-Didehydro-17β-estradiol; Estra-1,3,5(10),6,8-pentaen-3,17β-diol
Routes of
administration
By mouth
Drug classEstrogen
Identifiers
CAS Number
PubChem CID
ChemSpider
ChEMBL
Chemical and physical data
FormulaC18H20O2
Molar mass268.350 g/mol g·mol−1
3D model (JSmol)

17β-Dihydroequilenin, or β-dihydroequilenin, also known as δ6,8-17β-estradiol or 6,8-didehydro-17β-estradiol, as well as estra-1,3,5(10),6,8-pentaen-3,17β-diol, is a naturally occurring steroidal estrogen found in horses which is closely related to equilin, equilenin, and estradiol, and, as the 3-sulfate ester sodium salt, is a minor constituent (0.5%) of conjugated estrogens (Premarin).[1] 17β-Dihydroequilenin has unexpectedly shown a selective estrogen receptor modulator (SERM)-like profile of estrogenic activity in studies with monkeys, in which beneficial effects on bone and the cardiovascular system were noted but proliferative responses in breast and endometrium were not observed.[2]

Composition of conjugated estrogens and properties of constituents

Compound Synonym Proportion (%) Relative potency
in the vagina (%)
Relative potency
in the uterus (%)
RBA for
ERα (%)
RBA for
ERβ (%)
ERα / ERβ
RBA ratio
Conjugated estrogens 100 38 100
Estrone 49.1–61.5 30 32 26 52 0.50
Equilin Δ7-Estrone 22.4–30.5 42 80 13 49 0.26
17α-Dihydroequilin Δ7-17α-Estradiol 13.5–19.5 0.06 2.6 41 32 1.30
17α-Estradiol 2.5–9.5 0.11 3.5 19 42 0.45
Δ8-Estrone 3.5–3.9 ? ? 19 32 0.60
Equilenin Δ6,8-Estrone 2.2–2.8 1.3 11.4 15 20–29 0.50–0.75
17β-Dihydroequilin Δ7-17β-Estradiol 0.5–4.0 83 200 113 108 1.05
17α-Dihydroequilenin Δ6,8-17α-Estradiol 1.2–1.6 0.018 1.3 20 49 0.40
17β-Estradiol 0.56–0.9 100 ? 100 100 1.00
17β-Dihydroequilenin Δ6,8-17β-Estradiol 0.5–0.7 0.21 9.4 68 90 0.75
Δ8-17β-Estradiol Small amounts ? ? 68 72 0.94
Notes: All listed compounds are present in conjugated estrogen products specifically in the form of the sodium salts of the sulfate esters (i.e., as sodium estrone sulfate, sodium equilin sulfate, etc.). Sources: See template.

See also

References

  1. ^ Marc A. Fritz; Leon Speroff (28 March 2012). Clinical Gynecologic Endocrinology and Infertility. Lippincott Williams & Wilkins. pp. 751–. ISBN 978-1-4511-4847-3.
  2. ^ Cline JM (2007). "Assessing the mammary gland of nonhuman primates: effects of endogenous hormones and exogenous hormonal agents and growth factors". Birth Defects Res. B Dev. Reprod. Toxicol. 80 (2): 126–46. doi:10.1002/bdrb.20112. PMID 17443713.