Nutrabiotech Beta Estradiol 98% 100G Powder, 98% high purity Beta Estradiol powder, 17β-Estradiol steroid compound, estrogen receptor regulator, endocrine and cell physiology research raw material

CAS 50‑28‑2 Beta Estradiol Powder ERα ERβ High‑Affinity Ligand For Endocrine‑System and Breast‑Cancer Research

High‑purity β‑Estradiol (17β‑Estradiol, E2) powder CAS 50‑28‑2 is the primary biologically‑active endogenous steroid‑estrogen hormone in pre‑menopausal females. This white crystalline compound works as the high‑affinity agonist targeting estrogen‑receptor‑alpha (ERα), estrogen‑receptor‑beta (ERβ) and membrane‑bound GPR30 receptor. It regulates cell proliferation, endometrial‑cell growth, hippocampal neuronal‑plasticity, stem‑cell neural‑differentiation and multiple endocrine‑related signalling pathways. Widely utilised for laboratory‑scale research on hormone‑dependent tumour, mammary‑cancer, neurodegenerative‑disorders, menopause‑related symptoms, stem‑cell‑induction and endocrine‑pharmacology screening projects. Every‑batch undergoes strict HPLC purity inspection, bulk‑order service and customizable‑packaging are available for global endocrinology and molecular‑biology research‑oriented purchasers.

Category: Tags: , , , , , , , , , ,
beta-Estradiol (17beta-Estradiol, E2) CAS 50-28-2 | ERalpha / ERbeta Agonist, Steroid Hormone Standard

β-Estradiol CAS 50-28-2
17β-Estradiol (E2) — ERα / ERβ Agonist

The primary and most potent endogenous estrogen in humans, and the reference agonist for the nuclear estrogen receptors ERα (ESR1) and ERβ (ESR2) as well as the membrane receptor GPER (GPR30). 17β-Estradiol drives both classical genomic transcription through estrogen response elements and rapid non-genomic kinase signalling, making it indispensable in estrogen receptor biology, menopause and HRT research, bone health, neuroprotection, ER-positive breast and endometrial cancer models, cardiovascular biology and reproductive endocrinology.

ERα (ESR1) Agonist ERβ (ESR2) Agonist GPER / GPR30 Ligand Endogenous Estrogen Steroid Hormone Genomic + Non-Genomic Signalling Reference Standard
Request a Quote Technical Specs
272.38
MW (C18H24O2)
≥98%
Purity (HPLC)
ERα / ERβ
Sub-nanomolar Affinity

Molecular Information

Name: β-Estradiol (17β-Estradiol)
CAS: 50-28-2
Formula: C18H24O2
MW: 272.38 g/mol
Purity: ≥98% (HPLC)
Solubility: DMSO; ethanol (~50 mg/mL);
  poorly water soluble
SMILES: C[C@]12CC[C@H]3[C@@H]
  (CCc4cc(O)ccc34)[C@@H]1CC[C@@H]2O
InChIKey: VOXZDWNPVJITMN
  -ZBRFXRBCSA-N
MP: 176-180°C
Appearance: White to off-white crystalline powder
Synonyms: E2 / Estradiol /
  1,3,5(10)-Estratriene-3,17β-diol
Storage: Sealed, dry, protect from light
🧪
CAS Number
50-28-2
⚖️
Molecular Weight
272.38
🎯
Primary Activity
ERα/ERβ Agonist
✅
Purity
≥98%

17β-Estradiol Technical Specifications & Quality Control Data

Complete physicochemical properties, structural identifiers and QC release parameters for research-grade β-Estradiol (CAS 50-28-2)

📋 Physicochemical Properties

  • Product Nameβ-Estradiol (17β-Estradiol)
  • IUPAC Name(8R,9S,13S,14S,17S)-13-Methyl-6,7,8,9,11,12,13,14,15,16,17-dodecahydro-cyclopenta[a]phenanthrene-3,17-diol
  • CAS Number50-28-2
  • Common AbbreviationE2
  • SynonymsEstradiol / Dihydrofolliculin / 1,3,5(10)-Estratriene-3,17β-diol
  • Molecular FormulaC18H24O2
  • Molecular Weight272.38 g/mol
  • Exact Mass272.1776 Da
  • SMILESC[C@]12CC[C@H]3[C@@H](CCc4cc(O)ccc34)[C@@H]1CC[C@@H]2O
  • InChIKeyVOXZDWNPVJITMN-ZBRFXRBCSA-N
  • Stereocentres5 defined (8R, 9S, 13S, 14S, 17S)
  • AppearanceWhite to off-white crystalline powder
  • Melting Point176-180°C
  • MDL NumberMFCD00003693
  • PubChem CID5757
  • EC Number200-023-8

🔬 Quality Control & Handling

  • Purity (HPLC)≥98%
  • Identity1H-NMR / 13C-NMR / LC-MS conform
  • FormCrystalline powder
  • ColorWhite to off-white
  • Loss on Drying≤0.5%
  • Residue on Ignition≤0.1%
  • Heavy Metals≤20 ppm
  • Storage ConditionRoom temp or 2-8°C, sealed, protect from light
  • SolubilityEthanol ~50 mg/mL (clear, colorless); DMSO; poorly soluble in water
  • GHS ClassificationDanger; H351 Carc. 2; H360FD Repr. 1A; H362 Lact.; H410 Aquatic Chronic 1
  • Cell Culture SuitabilitySuitable (mammalian)
  • QC DocumentationCOA / HPLC / NMR / MS / MSDS
  • Pack Sizes1g / 5g / 10g / 100g / 1KG
  • Stock StatusIn Stock
  • Use StatementResearch use only; not for human or clinical use

Estrogen Receptor Targets & Downstream Signalling Nodes

17β-Estradiol engages nuclear and membrane estrogen receptors, then propagates through a broad transcriptional and kinase network across virtually every organ system

🧬 ERα / ESR1 (Nuclear Receptor NR3A1) 🧭 ERβ / ESR2 (Nuclear Receptor NR3A2) 📡 GPER / GPR30 (Membrane GPCR) 🧩 ER-X / Membrane-Associated ER 📜 Estrogen Response Elements (ERE) 🔄 SRC-1 / CBP / p300 Coactivators ⚡ PI3K / AKT Pathway 🔥 MAPK / ERK1/2 Cascade 🩸 eNOS / Nitric Oxide Signalling 🪤 Cyclin D1 & c-Myc Transcription 🦴 RANKL / OPG Bone Axis 🎬 SHBG Binding & Transport 💉 ERRα / ERRβ (Related Orphan Receptors) 🧠 BDNF / Synaptic Plasticity

How 17β-Estradiol Works: Genomic and Non-Genomic Mechanism of Action

Estradiol signalling operates on two timescales — a slow transcriptional programme measured in hours and a rapid membrane-initiated kinase response measured in seconds

1

Membrane Diffusion & Receptor Binding

As a small lipophilic steroid, 17β-estradiol crosses the plasma membrane freely and binds the ligand-binding domain (LBD) of ERα or ERβ with sub-nanomolar affinity. The phenolic A-ring 3-OH and the 17β-OH form the critical hydrogen-bond anchor points with Glu353/Arg394 and His524.

2

Helix 12 Repositioning

Agonist binding folds helix 12 of the LBD across the ligand pocket, creating the AF-2 coactivator groove. This is the conformational switch first visualised in the Brzozowski et al. Nature 1997 crystal structures that distinguishes agonists from SERMs such as raloxifene.

3

Chaperone Release & Dimerisation

Heat shock protein chaperones (HSP90, HSP70) dissociate, the receptor is phosphorylated, and two liganded receptors form ERα/ERα, ERβ/ERβ homodimers or ERα/ERβ heterodimers, each with distinct transcriptional output.

4

ERE Binding & Transcription

The dimer engages estrogen response elements in target gene promoters via its zinc-finger DNA-binding domain and recruits SRC-1, CBP/p300 and the mediator complex, activating transcription of cyclin D1, c-Myc, PGR, TFF1/pS2 and hundreds of other estrogen-responsive genes.

5

Rapid Non-Genomic Signalling

A palmitoylated membrane pool of ER and the GPCR GPER (GPR30) trigger second-messenger responses within seconds to minutes: cAMP generation, intracellular calcium flux, PI3K/AKT activation, MAPK/ERK phosphorylation and eNOS-derived nitric oxide release causing vasodilation.

6

Tissue-Specific Physiological Output

The integrated response is tissue dependent: proliferation and differentiation in mammary and endometrial epithelium, suppression of osteoclastogenesis via the RANKL/OPG axis in bone, neurotrophic and anti-apoptotic effects in CNS neurons, and endothelial protection in the vasculature.

17β-Estradiol Research Applications & Experimental Models

E2 is one of the most widely deployed reference hormones in biomedical research, spanning nuclear receptor pharmacology, oncology, skeletal biology, neuroscience and reproductive endocrinology

🧬

Estrogen Receptor Biology & Nuclear Receptor Pharmacology

The gold-standard full agonist for ERα and ERβ in competitive radioligand binding, fluorescence polarisation, ERE-luciferase reporter, coactivator recruitment and ChIP-seq experiments. Serves as the positive control against which SERMs (tamoxifen, raloxifene) and SERDs (fulvestrant) are benchmarked.

Reference Agonist
🌿

Menopause & Hormone Replacement Therapy Research

Estradiol decline at menopause drives vasomotor symptoms, urogenital atrophy, accelerated bone loss and altered cardiometabolic risk. E2 is used in ovariectomised rodent models to reconstruct the postmenopausal state and to test HRT regimens, tissue-selective estrogen complexes and phytoestrogen alternatives.

HRT & Menopause
🦴

Bone Health & Osteoporosis

Estradiol suppresses osteoclastogenesis by shifting the RANKL/OPG ratio and promoting osteoclast apoptosis while supporting osteoblast survival. Central to ovariectomy-induced osteoporosis models, micro-CT bone density studies and osteoblast/osteoclast co-culture assays.

Skeletal Biology
🧠

Neuroprotection & Neuroendocrinology

E2 upregulates BDNF, enhances hippocampal spine density and synaptic plasticity, and reduces excitotoxic and oxidative neuronal injury. Applied in stroke, Alzheimer's disease, traumatic brain injury and cognitive ageing models, and in hypothalamic-pituitary-gonadal axis feedback studies.

CNS Research
🦠

ER-Positive Breast & Endometrial Cancer

Roughly 70-80% of breast cancers are ER-positive. Estradiol is the canonical proliferative stimulus in MCF-7, T47D, ZR-75-1 and Ishikawa cell models, in endocrine-resistance studies (ESR1 mutations, CDK4/6 inhibitor combinations) and in estrogen-dependent xenograft experiments.

Oncology
💓

Cardiovascular & Vascular Biology

Rapid non-genomic activation of eNOS produces nitric oxide-dependent vasodilation; E2 also modulates lipid profiles, endothelial repair and vascular inflammation. Used in endothelial cell culture, aortic ring myography and atherosclerosis models to probe the female cardiovascular protection hypothesis.

Vascular
🥦

Reproductive Endocrinology & Fertility

Essential for follicular development, endometrial receptivity, oocyte maturation and the LH surge. Routinely supplemented in in vitro maturation (IVM) media for bovine and porcine cumulus-oocyte complexes and in embryo implantation and uterotrophic assay protocols.

Reproductive Biology
🌍

Endocrine Disruption & Environmental Toxicology

17β-Estradiol is the mandated reference estrogen in OECD-aligned screening assays including the uterotrophic bioassay, E-SCREEN, ER transactivation (ERTA) and yeast estrogen screen (YES). It anchors the potency scale used to characterise bisphenols, parabens and other suspected endocrine disruptors.

Regulatory Standard
📊

Analytical Chemistry & Immunoassay Calibration

Used as a certified-quality reference standard for LC-MS/MS and GC-MS quantification of steroid panels, for ELISA and chemiluminescence immunoassay calibration curves, and for method validation in clinical endocrinology and anti-doping laboratories.

Reference Standard

Key Publications on Estradiol & Estrogen Receptor Biology

Foundational literature spanning receptor discovery, structural biology and clinical endocrinology

Jensen EV, Jacobson HI. Basic guides to the mechanism of estrogen action. Recent Progress in Hormone Research. 1962;18:387-414. — the study that established the existence of a specific intracellular estrogen-binding receptor.
Foundational work; see also Jensen EV, DeSombre ER. Science. 1973;182(4108):126-134. doi: 10.1126/science.182.4108.126
Brzozowski AM, Pike ACW, Dauter Z, et al. Molecular basis of agonism and antagonism in the oestrogen receptor. Nature. 1997;389(6652):753-758.
doi: 10.1038/39645
Kuiper GGJM, Enmark E, Pelto-Huikko M, et al. Cloning of a novel estrogen receptor expressed in rat prostate and ovary. Proceedings of the National Academy of Sciences USA. 1996;93(12):5925-5930. — the discovery of ERβ.
doi: 10.1073/pnas.93.12.5925
Revankar CM, Cimino DF, Sklar LA, et al. A transmembrane intracellular estrogen receptor mediates rapid cell signaling. Science. 2005;307(5715):1625-1630. — characterisation of GPER/GPR30.
doi: 10.1126/science.1106943
Heldring N, Pike A, Andersson S, et al. Estrogen receptors: how do they signal and what are their targets. Physiological Reviews. 2007;87(3):905-931.
doi: 10.1152/physrev.00026.2006
Rossouw JE, Anderson GL, Prentice RL, et al. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. JAMA. 2002;288(3):321-333.
doi: 10.1001/jama.288.3.321
Nilsson S, Makela S, Treuter E, et al. Mechanisms of estrogen action. Physiological Reviews. 2001;81(4):1535-1565.
doi: 10.1152/physrev.2001.81.4.1535

β-Estradiol Pack Sizes & Ordering Information

Research-grade 17β-Estradiol (CAS 50-28-2) supplied in 1g / 5g / 10g / 100g / 1KG with full QC documentation; custom bulk quantities supported

TierPack SizeStock StatusSuitable ForShipping & Lead Time
Standard1 gIn StockERE-reporter assays, MCF-7 proliferation, receptor binding studiesAmbient shipping in amber container; same/next-day dispatch
Medium5 gIn StockOvariectomised rodent models, pellet implantation, uterotrophic assaysAmbient shipping; same/next-day dispatch
Large10 gIn StockLong-term in vivo studies, multi-lab consortia, screening campaignsAmbient shipping; same/next-day dispatch
Bulk100 gIn StockFormulation development, transdermal and implant research, standard productionCarton or drum, light-protected; quote to confirm dispatch
Industrial1 KGMade to orderPilot and production scale, CMO/CDMO supply, process validation batchesDrum shipment with batch COA; scheduled batch delivery

💡 Reference pack sizes shown above; for exact pricing, lot availability and bulk 17β-estradiol supply please contact us for a quote. Tiered discounts apply to bulk orders.

β-Estradiol FAQ — Frequently Asked Questions

Common technical and scientific questions about 17β-estradiol pharmacology, handling and sourcing

What is β-Estradiol (CAS 50-28-2) and why is it called E2?
β-Estradiol, properly named 17β-estradiol, is the principal and most potent endogenous estrogen in humans (C18H24O2, MW 272.38). The abbreviation E2 refers to the two hydroxyl groups on the steroid skeleton, distinguishing it from estrone (E1, one hydroxyl), estriol (E3, three hydroxyls) and estetrol (E4). It is synthesised from testosterone by aromatase (CYP19A1), predominantly in ovarian granulosa cells and, after menopause, in adipose and other peripheral tissues.
17β-Estradiol vs 17α-estradiol — which one do I need?
The prefix denotes the stereochemistry of the C17 hydroxyl group on the steroid D-ring. In the 17β epimer the hydroxyl projects on the β face, which is geometrically required for high-affinity docking into the ER ligand-binding pocket (hydrogen bonding to His524 in ERα). 17α-estradiol is roughly 100-fold weaker as a classical estrogen and is studied separately as a "non-feminising" neuroprotective and longevity compound. If your protocol calls for estrogenic activity, ER activation or a positive control in an ERE reporter assay, you need the 17β isomer (CAS 50-28-2) supplied here.
What is the difference between ERα and ERβ, and does estradiol prefer one?
ERα (gene ESR1, chromosome 6q25) and ERβ (gene ESR2, chromosome 14q23) are separate gene products sharing ~96% identity in the DNA-binding domain but only ~53% in the ligand-binding domain. ERα dominates in uterus, mammary gland, liver and bone and mediates proliferative responses; ERβ dominates in prostate, granulosa cells, colon, lung and CNS and often antagonises ERα-driven proliferation. 17β-Estradiol binds both subtypes with comparable sub-nanomolar affinity, which is precisely why it is used as the non-selective reference agonist and paired with subtype-selective ligands (PPT for ERα, DPN for ERβ) to dissect subtype contributions.
How does estradiol produce effects within seconds if it works through transcription?
It uses two parallel mechanisms. The classical genomic pathway (receptor dimerisation, ERE binding, coactivator recruitment) takes hours and changes protein levels. The non-genomic pathway acts within seconds to minutes through a palmitoylated membrane pool of ER and through GPER/GPR30, a seven-transmembrane GPCR. These membrane-initiated events trigger cAMP, calcium flux, PI3K/AKT, MAPK/ERK and eNOS-derived nitric oxide. The rapid vasodilation seen on estradiol infusion is a classic demonstration of this non-genomic arm.
Why is estradiol associated with breast and endometrial cancer risk?
About 70-80% of breast cancers are ER-positive and depend on ERα signalling for growth. Estradiol induces transcription of cyclin D1, c-Myc and PGR, driving G1/S transition and proliferation. Prolonged unopposed estrogen exposure similarly increases endometrial proliferation and hyperplasia risk. Additionally, oxidative metabolism of estradiol can yield catechol estrogen quinones capable of forming DNA adducts. This biology is the rationale for endocrine therapies — SERMs (tamoxifen), SERDs (fulvestrant) and aromatase inhibitors — and makes E2 the standard proliferative stimulus in MCF-7 and Ishikawa models.
How should I dissolve and store 17β-estradiol for cell culture?
Estradiol is poorly water soluble but dissolves readily in absolute ethanol at approximately 50 mg/mL and in DMSO. Prepare a 10 mM stock, sterile-filter, aliquot into amber vials and store at -20°C protected from light to avoid oxidation and freeze-thaw degradation. Dilute serially into medium keeping the final vehicle at or below 0.1% v/v. Critically, for estrogen-response experiments use phenol-red-free medium with charcoal-dextran-stripped FBS, since phenol red is weakly estrogenic and standard serum contains endogenous steroids that will mask your treatment effect.
What concentration of estradiol should I use in vitro?
Physiological circulating E2 in premenopausal women ranges roughly 0.1-1 nM, and most ER-mediated cellular responses saturate in the 0.1 to 10 nM window. A typical MCF-7 proliferation experiment uses 1 nM (10-9 M) with a vehicle control and often a fulvestrant or ICI 182,780 co-treatment arm to confirm ER dependence. Concentrations above 1 µM frequently produce off-target and cytotoxic effects unrelated to receptor activation and should be interpreted with caution. Always run a full dose-response to establish the EC50 in your specific system.
Is 17β-estradiol used as a regulatory reference standard?
Yes. 17β-Estradiol is the mandated positive reference estrogen in internationally harmonised endocrine disruptor screening assays, including the OECD uterotrophic bioassay (TG 440), the ER transactivation assays (TG 455), the E-SCREEN proliferation assay and the yeast estrogen screen (YES). Relative estrogenic potencies of test chemicals such as bisphenol A, nonylphenol and parabens are expressed as estradiol equivalents, making high-purity E2 essential for regulatory-grade toxicology work.
What safety precautions apply when handling estradiol powder?
Estradiol carries serious hazard classifications: H351 (suspected of causing cancer, Carc. 2), H360FD (may damage fertility and the unborn child, Repr. 1A), H362 (may cause harm to breastfed children) and H410 (very toxic to aquatic life with long-lasting effects). Handle the powder in a fume hood or containment enclosure with gloves, lab coat, eye protection and an N95/P3 respirator to prevent dust inhalation. Pregnant or nursing personnel should not handle this material. Do not dispose to drains — collect as hazardous waste. Review the full SDS before first use.
What purity, documentation and pack sizes are available?
Research-grade 17β-estradiol is supplied at ≥98% purity by HPLC, with each batch accompanied by a Certificate of Analysis covering HPLC purity, 1H/13C NMR, mass spectrometry, melting point and appearance. Pack sizes of 1 g, 5 g, 10 g and 100 g are in stock, with 1 KG produced made-to-order. MSDS/SDS, residual solvent data and Certificates of Origin are available on request. Contact us for pricing, sample evaluation or custom specifications.

Need 17β-Estradiol for Your Endocrinology Research?

Research-grade β-Estradiol (CAS 50-28-2) — C18H24O2, MW 272.38, purity ≥98% HPLC, COA included
The reference ERα/ERβ agonist for estrogen receptor biology — available 1g to 1KG

Request a Quote →

Related products