17alpha-Estradiol

17α-雌二醇

Also known as: α-Estradiol, Alfatradiol, Epiestradiol, 17-Epiestradiol, Estra-1,3,5(10)-triene-3,17a-diol, Epiestrol, 17α-Oestradiol, 17a-Oestradiol, Oestra-1,3,5(10)-triene-3,17a-diol, 17α-estradiol, (8R,9S,13S,14S,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,17-diol, MFCD00064144

17alpha-Estradiol (CAS 57-91-0) is a compound in the Alcohols category listed in the Jingsj chemical database. It has the molecular formula C18H24O2 and a molecular weight of 272.382 g/mol. It is also known as α-Estradiol, Alfatradiol and Epiestradiol. Key properties include a melting point of 176-180ºC(lit.), a boiling point of 445.9±45.0 °C at 760 mmHg, a density of 1.2±0.1 g/cm3 and a flash point of 209.6±23.3 °C. It is classified under GHS with signal word Warning and hazard statements H351 — Suspected of causing cancer. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 57-91-0
Jingsj CID: J-16929-7
Molecular Formula: C₁₈H₂₄O₂
Chinese Name: 17α-雌二醇
Molecular Weight: 272.382 g/mol
Category: Alcohols
Last updated: 8/21/2026

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Physicochemical Properties

Melting Point	176-180ºC(lit.)
Boiling Point	445.9±45.0 °C at 760 mmHg
Density	1.2±0.1 g/cm3
Flash Point	209.6±23.3 °C
Exact Mass	272.177643
PSA	40.46000
LogP	4.13
Vapor Pressure	0.0±1.1 mmHg at 25°C
Refractive Index	1.599
Storage Conditions	0-6°C
Additional Property	ethanol: 50 mg/mL, clear, colorless

GHS Safety & Compliance

Health HazardSignal word: Warning

H351 — Suspected of causing cancer

Activity & Biological Data

Target	Human Endogenous Metabolite
Additional Information	[1]. Schriefers H, et al. Inhibition of testosterone metabolism by 17-alpha-estradiol in rat liver slices. Arzneimittelforschung. 1991 Nov;41(11):1186-9. [2]. Santos RS, et al. The effects of 17 alpha-estradiol to inhibit inflammation in vitro. Biol Sex Differ. 2017 Sep 6;8:30. [3]. Zhang HB, et al. 17-Alpha-estradiol ameliorating oxygen-induced retinopathy in a murine model. Jpn J Ophthalmol. 2012 Jul;56(4):407-15.

Target

Human Endogenous Metabolite

Additional Information

[1]. Schriefers H, et al. Inhibition of testosterone metabolism by 17-alpha-estradiol in rat liver slices. Arzneimittelforschung. 1991 Nov;41(11):1186-9. [2]. Santos RS, et al. The effects of 17 alpha-estradiol to inhibit inflammation in vitro. Biol Sex Differ. 2017 Sep 6;8:30. [3]. Zhang HB, et al. 17-Alpha-estradiol ameliorating oxygen-induced retinopathy in a murine model. Jpn J Ophthalmol. 2012 Jul;56(4):407-15.

Frequently Asked Questions

What is the CAS number of 17alpha-Estradiol?

The CAS number of 17alpha-Estradiol is 57-91-0.

What are the molecular formula and molecular weight of 17alpha-Estradiol?

17alpha-Estradiol has molecular formula C18H24O2 and molecular weight 272.382 g/mol.

Is 17alpha-Estradiol hazardous?

17alpha-Estradiol has GHS signal word Warning and hazard statements H351 — Suspected of causing cancer.

What are the upstream and downstream products of 17alpha-Estradiol?

For 17alpha-Estradiol, Upstream Products: Estrone, 1-Pentanol, 17α-Dihydroequilenin; Downstream Products: Estradiol.

Data compiled from public chemical databases and supplier catalogs; supplier offers are provided by suppliers.

Last updated: 8/21/2026

How to cite: Jingsj. "17alpha-Estradiol (CAS 57-91-0)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-16929-7 (accessed 2026-10-28).

Data for reference only; verify specifications, grades and regulatory status with suppliers before purchase.