S-Equol
S-Equol
Key Specifications
| CAS Number | 531-95-3 |
| Purity | ≥98.0% |
| Molecular Formula | C₁₅H₁₄O₃ |
| Molecular Weight | 242.27 g/mol |
| Appearance | White to off-white crystalline powder |
| Solubility | Slightly soluble in water; soluble in ethanol |
| Storage | Room temperature, protect from light |
| Shelf Life | 24 months |
CAS 531-95-3
What Is S-Equol?
S-Equol (CAS 531-95-3) is a non-steroidal isoflavandiol phytoestrogen with molecular formula C15H14O3 and molecular weight 242.27 g/mol. In nature it forms as a gut-microbial metabolite of the soy isoflavone daidzein, generated when specific intestinal bacteria reduce daidzein through dihydrodaidzein and tetrahydrodaidzein intermediates; however, only an estimated 30-50% of people carry the gut flora needed to produce it naturally ("equol producers"). Because this conversion cannot be relied upon through diet alone, commercial bulk S-equol is generally manufactured by microbial biotransformation: engineered bacteria carrying the natural equol-producing enzyme pathway convert plant-derived daidzein into the single, non-racemic S-enantiomer under controlled fermentation conditions, followed by extraction, purification, and crystallization to consistent nutraceutical-grade purity.
Other Names
Key Features
High-Purity Non-Racemic S-Configuration
HPLC purity ≥98.0% with a single, verified S-enantiomer (non-racemic), delivering the isoflavandiol form with high selectivity for ERβ rather than a mixed R/S product.
Controlled Biocatalytic Production
Produced via engineered microbial biotransformation of plant-derived daidzein rather than chemical racemic synthesis, giving tighter batch-to-batch consistency and a documented process route.
Fine Crystalline Powder Form
Supplied as a white to off-white crystalline powder with controlled particle size, supporting consistent dissolution and ease of handling in downstream formulation.
Rigorous Contaminant Screening
Every batch is screened for heavy metals (Pb, As, Cd, Hg) and microbial limits (total plate count, yeast/mold, E. coli, Salmonella) to support food- and cosmetic-grade use.
Flexible Bulk & OEM Supply
Available in flexible bulk quantities with OEM/private-label documentation support (COA, MSDS, specification sheets) for supplement, skincare, and finished-dose manufacturers.
| Molecular Formula | C₁₅H₁₄O₃ |
| Molecular Weight | 242.27 g/mol |
| Appearance | White to off-white crystalline powder |
| Solubility | Slightly soluble in water; soluble in ethanol |
| Storage Condition | Room temperature, protect from light |
| Shelf Life | 24 months |
| Grade 1 | Supplement Grade · ≥98.0% · COA |
End-Product Applications
Overview
S-Equol is the bioactive phytoestrogen metabolite of daidzein with high ERβ selectivity (the "safe" estrogen receptor). PathGene produces exclusively the S-configuration (not racemic) via recombinant E. coli bioconversion — 40% lower cost vs. chemical resolution while maintaining ≥98% HPLC purity with endotoxin control.
Mechanism & Benefits
selective ERβ agonist → reduces menopause hot flashes, supports bone mineral density, anti-photoaging. Typical supplement dosage: 10–30 mg/serving. Topical dosage: 0.5–2% in emulsions/serums
Compatible Formulations
softgel capsule, tablet, topical emulsion, serum
Target Market
women's health supplement brands (40+ consumers), cosmetic brands targeting mature skin, menopause management product lines
Packaging Options
100 g 500 g 1 kg
Lead Time
7–10 business days
Minimum Order
100 g
Custom Packaging
Custom packaging (foil bags, HDPE drums), GMP labeling, and export documentation are available. Contact us for specifics.Certifications
ISO
ISO
Manufacturing Process
Substrate Preparation
Food-grade daidzein, extracted and purified from soybean isoflavone concentrate, is prepared as the starting substrate for bioconversion.
Biocatalyst Strain Fermentation
A recombinant Escherichia coli strain carrying the natural equol-producing enzyme cassette (originally identified in equol-producing gut bacteria) is fermented under controlled temperature, pH, and aeration to generate active biocatalyst biomass.
Enzymatic Bioconversion
Daidzein is fed into the bioreactor and sequentially reduced through dihydrodaidzein and tetrahydrodaidzein intermediates by the enzyme cascade, with cofactor regeneration maintained, to yield exclusively the S-configuration equol.
Biomass Removal / Clarification
The bioconversion broth is centrifuged and/or microfiltered to remove residual cell biomass, yielding a clarified S-equol-containing solution.
Extraction
S-equol is extracted from the clarified solution using food-grade organic solvent (e.g., ethyl acetate), followed by solvent recovery and concentration.
Crystallization & Recrystallization
The concentrate undergoes controlled crystallization and recrystallization to remove residual daidzein, intermediates, and process impurities, raising chemical and chiral purity.
Drying & Micronization
Crystals are vacuum-dried to remove residual solvent and moisture, then milled/sieved to a controlled fine powder particle size.
QC Testing & Packaging
Each batch is tested for assay, chiral purity, heavy metals, and microbial limits, then packed in sealed, moisture-protective containers under GMP-aligned conditions.
Quality Specifications
| Test Item | Specification | Result |
|---|---|---|
| Appearance | White to off-white crystalline powder | Conforms |
| Odor | Characteristic, essentially odorless | Conforms |
| Assay (HPLC) | ≥98.0% | 98.4% |
| Chiral Purity (S-isomer) | ≥99.0% (non-racemic) | 99.3% |
| Particle Size | 100% through 80 mesh | Conforms |
| Loss on Drying | ≤0.5% | 0.3% |
| Lead (Pb) | ≤2 mg/kg | <1 mg/kg |
| Arsenic (As) | ≤2 mg/kg | <1 mg/kg |
| Cadmium (Cd) | ≤1 mg/kg | <0.5 mg/kg |
| Mercury (Hg) | ≤0.1 mg/kg | <0.05 mg/kg |
| Total Plate Count | ≤1000 CFU/g | <100 CFU/g |
| Yeast & Mold | ≤100 CFU/g | <10 CFU/g |
| E. coli | Negative/25g | Negative |
| Salmonella | Negative/25g | Negative |
Purity & Assay Method
Purity and identity are determined by reversed-phase HPLC with UV detection, quantified against a certified S-equol reference standard; chiral HPLC or polarimetry is used separately to confirm the S-configuration is non-racemic. Buyers should request the batch-specific Certificate of Analysis and, for chirality-sensitive applications, ask for the chiral purity data (not just total isoflavandiol content) to confirm the material is not an R/S mixture.
Solubility & Formulation
S-equol is slightly soluble in water but readily soluble in ethanol and most polar organic solvents, a profile typical of isoflavandiol-class phytoestrogens. For oral soft-gel or tablet formulations, it is commonly pre-dissolved or co-processed with edible oils, lecithin, or cyclodextrin-based carriers to improve dispersibility and bioavailability; for topical creams, serums, and emulsions, it is typically incorporated into the oil phase or solubilized with an ethanol/glycol co-solvent system before emulsification. Formulators should confirm compatibility and target concentration with small-scale trials before scale-up.
Available Product Forms
Bulk S-Equol Powder
High-purity raw powder for supplement factories, research organizations, ingredient distributors, and contract manufacturers.
S-Equol Capsules
Custom capsule strength, shell material, bottle count, excipients, and label design for private-label brands.
S-Equol Tablets
Tablet formulation, granulation, compression, coating, bottle packaging, and custom labeling support.
S-Equol Powder Blends
S-Equol can be blended with complementary actives (antioxidants, other longevity ingredients, vitamins, minerals) per customer formula.
How is the ≥98% purity of S-equol confirmed?+
Each batch is tested by HPLC against a certified reference standard, with chiral analysis confirming the material is a single non-racemic S-enantiomer rather than an R/S mixture. A batch-specific COA is provided with every shipment.
How is your S-equol produced, and is it plant-derived or synthetic?+
It is produced by microbial biotransformation: an engineered bacterial strain carrying the natural equol-producing enzyme pathway converts plant-derived daidzein (from soy isoflavone extract) into the single S-configuration product, followed by extraction and purification. This differs from chemical racemic synthesis in that it avoids downstream chiral resolution.
Is S-equol soluble in water, and how should it be formulated?+
S-equol is only slightly soluble in water but soluble in ethanol; it is commonly solubilized with oils, lecithin, or cyclodextrin carriers for oral dosage forms, or dissolved in an ethanol/glycol system for topical formulations.
Can we request a sample before placing a bulk order?+
Yes, small trial samples are available for formulation testing and internal quality verification prior to committing to a bulk purchase order.
Do you support independent third-party testing?+
Yes, samples and shipments can be submitted to an accredited third-party laboratory of the buyer's choice for independent verification of purity, chirality, heavy metals, and microbial limits.
Do you offer OEM or private-label services for finished products?+
Yes, we support OEM and private-label programs for soft-gels, tablets, and topical formulations, including formulation guidance and full technical documentation (COA, MSDS, specification sheet, TDS).
What packaging options are available for bulk shipments?+
Standard packaging is in sealed, moisture- and light-protective containers (e.g., aluminum foil bags or drums with double-layer liners); custom packaging sizes and formats can be arranged for larger orders.
What is the MOQ, and how can we get a quotation?+
MOQ varies by application volume and packaging format; please contact our sales team with your target quantity, purity requirement, and intended use for a tailored quotation and lead-time estimate.
Why Choose PathGene
- Direct China manufacturer supply — factory pricing, no middleman
- Batch-specific COA & full traceability on every shipment
- In-house R&D + synthetic biology / enzymatic production platform
- Free sample for qualified B2B buyers before commercial order
- Flexible MOQ — from lab-scale trial to ton-scale commercial supply
- One-stop OEM/private-label support for finished dosage forms
- Worldwide shipping by courier, air freight, and sea freight
OEM & Private-Label Services
- ·Custom capsule manufacturing
- ·Custom tablet manufacturing
- ·Powder blending & custom formulation
- ·Private-label bottles, pouches & labels
- ·Small trial orders
- ·Bulk commercial production
- ·Export documentation
- ·Third-party laboratory testing
Documents Available
- ·Certificate of Analysis (COA)
- ·Product specification sheet
- ·Material Safety Data Sheet (MSDS)
- ·Manufacturing flow chart
- ·HPLC test report
- ·Heavy-metal test report
- ·Microbiological test report
- ·Non-GMO / allergen statement
- ·Country-of-origin documentation
- ·Packing list & commercial invoice
Certificate availability should be confirmed with our sales team before ordering.
Sample Certificate of Analysis
PathGene Biotech Co., Ltd.
南京派琪生物科技有限公司
CERTIFICATE OF ANALYSIS
Layout example — not an issued batch record
Product Name
S-Equol
CAS No.
531-95-3
Batch No.
PG-SAMPLE-000000
Packaging
Issued upon order confirmation
| Test Item | Specification | Result |
|---|---|---|
| Appearance | White to off-white crystalline powder | Conforms |
| Odor | Characteristic, essentially odorless | Conforms |
| Assay (HPLC) | ≥98.0% | 98.4% |
| Chiral Purity (S-isomer) | ≥99.0% (non-racemic) | 99.3% |
| Particle Size | 100% through 80 mesh | Conforms |
| Loss on Drying | ≤0.5% | 0.3% |
| Lead (Pb) | ≤2 mg/kg | <1 mg/kg |
| Arsenic (As) | ≤2 mg/kg | <1 mg/kg |
| Cadmium (Cd) | ≤1 mg/kg | <0.5 mg/kg |
| Mercury (Hg) | ≤0.1 mg/kg | <0.05 mg/kg |
| Total Plate Count | ≤1000 CFU/g | <100 CFU/g |
| Yeast & Mold | ≤100 CFU/g | <10 CFU/g |
| E. coli | Negative/25g | Negative |
| Salmonella | Negative/25g | Negative |
Conclusion: Conforms to internal quality specifications
The COA issued with your order will carry the actual batch number, manufacture/test dates, and QC signature.
Related Products
PQQ
Pyrroloquinoline Quinone Disodium Salt
Interested in S-Equol?
Our R&D team will respond to your inquiry or sample request within 24 hours.
