S-Equol
CAS 531-95-3
Purity≥98.0%
S-equol material for women's-health and isoflavone research
S-Equol powder (CAS 531-95-3) is a fermentation-derived S-enantiomer ingredient with a chemical-purity specification of ≥98.0%. Chemical purity and the S/R enantiomer ratio are different measurements. Batch COA and evaluation samples are available; MOQ 100 g, with 100 g, 500 g and 1 kg packs. healthy-aging ingredients
Quote / sample & delivery
Key Specifications
| Product Positioning | S-equol material for women's-health and isoflavone research |
| Application Scenarios | women's-health nutrition formulation · isoflavone metabolism research · skin-care formulation evaluation |
| 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 |
Procurement & delivery
Supply details confirmed by intended use, volume and target market
S-Equol is the S-enantiomer of equol, an isoflavandiol related to daidzein metabolism. This procurement page covers S-Equol powder, CAS 531-95-3, rather than an unspecified R/S equol mixture. For supplier qualification, review identity, chemical purity, assay basis and stereochemical evidence as separate items. An ordinary HPLC purity percentage does not establish the S/R ratio. Request documents matching the evaluated sample and the lot offered for delivery.
Chemical Purity and Dry-Basis Assay
S-Equol specification: purity ≥98.0%. Batch PGSEQ-260716 reports 99.9% chemical purity and 99.9% dry-basis assay. These are lot results and do not establish an S/R enantiomer ratio.
Specific Optical Rotation: −22° in Listed Lot
COA PGSEQ-260716 records specific optical rotation of −22° against [α]D < −21°. Review the measurement conditions in the document; optical rotation and a quantitative chiral S/R measurement are different tests.
Daidzein Bioconversion and Purification
S-Equol production uses daidzein bioconversion followed by purification. Connect the manufacturing review with material identity, chemical purity and stereochemical documentation for the supplied ingredient.
Solubility for Solid and Topical Development
S-Equol is slightly soluble in water and soluble in ethanol. For oral solids, evaluate powder uniformity and dissolution; for creams and serums, compare dispersion, crystallization and stability in the selected system.
Loss on Drying and Ethanol Residue
Batch PGSEQ-260716 recorded loss on drying of 0.04% (limit ≤1.0%) and ethanol residue of 76 ppm (limit ≤200 ppm). These separate COA items support powder and residual-solvent review for that lot.
Bulk Ingredient Packs and Samples
MOQ 100 g; packaging options are 100 g, 500 g and 1 kg. Evaluation samples and batch documents support qualification before commercial sourcing.
Test items, specifications and results for the listed batch are shown here. View or request a COA in the quality documents section.
Batch No.
PGSEQ-260716
Test date
2026-07-30
Specification
In-house
Pack size
1 kg/bag
Storage
Room temperature, protect from light
Conclusion
Conforms
| Test Item | Specification | Result |
|---|---|---|
| Appearance | White to off-white crystalline powder | White crystal powder |
| Identification | IR spectrum concordant with reference | Complies |
| Solution clarity and color | Clear and colorless | Complies |
| Purity | ≥98% | 99.9% |
| Assay (dry basis) | ≥98% | 99.9% |
| Loss on drying | ≤1.0% | 0.04% |
| Ethanol residue | ≤200 ppm | 76 ppm |
| Melting point | 185–195℃ | 189℃ |
| Specific optical rotation | [α]D < −21° | −22° |
| Lead (Pb) | ≤1.0 ppm | Not detected |
| Mercury (Hg) | ≤1.0 ppm | Not detected |
| Cadmium (Cd) | ≤1.0 ppm | Not detected |
| Arsenic (As) | ≤1.0 ppm | Not detected |
| Total plate count | ≤1000 CFU/g | <10 CFU/g |
| Yeast and mold | ≤100 CFU/g | <10 CFU/g |
| Coliforms | Not detected | <0.3 MPN/g |
| Staphylococcus aureus | Not detected | Not detected |
| Salmonella | Not detected | Not detected |
Request a reviewed COA through the quality documents section and confirm its product form and batch.
Hard capsules
Powders
Softgels
Tablets
Sublingual tablets
Oral dissolving films
Keep S-enantiomeric purity separate from chemical purity; address limited solubility separately for oral/topical use.
99.9%
Purity
99.9%
Assay (dry basis)
PGSEQ-260716 · Results apply to this lot; interpret purity, assay and water on their respective bases.
Composition candidates, processing sequences and tests support pilot design. Confirm candidate excipients and processes using this material in the actual finished formulation.
Application examples follow the materials, formats and findings actually studied. Combination studies, single-ingredient studies, commercial precedents and development candidates are distinguished.
A studied equol/resveratrol tablet provides a formulation precedent, but its fermented-soy matrix differs from isolated S-equol.
Show research and formulation insights +Hide details −Combination / selection rationale: A studied equol/resveratrol tablet provides a formulation precedent, but its fermented-soy matrix differs from isolated S-equol.
Published evidence / source details: A 2023 trial randomized 76 women and analysed 60 after 12 months. Tablets contained 200 mg fermented soy, including 80 mg isoflavone aglycones and 10 mg equol, plus 25 mg resveratrol; bone-marker changes were reported.
Development insights: Specify stereochemistry, assay and resveratrol form for an isolated-S-equol prototype. Assess dry blending and disintegration and document removal of other soy constituents, retaining single-ingredient controls.
Evidence scope: The paper does not verify this supplied isolated S-grade; findings concern the whole tablet, not guaranteed isolated-S-equol synergy.
2023 · Corbi et al. · DOI 10.3390/ijms241512063 ↗Direct oral S-equol research informs ingredient identity and endpoint selection for women’s nutrition and beauty-from-within projects.
Show research and formulation insights +Hide details −Combination / selection rationale: Direct oral S-equol research informs ingredient identity and endpoint selection for women’s nutrition and beauty-from-within projects.
Published evidence / source details: A 2012 trial compared placebo with 10 or 30 mg/day S-equol for 12 weeks in 101 postmenopausal Japanese women. Wrinkle area improved; other skin endpoints, including hydration and water loss, did not significantly differ.
Development insights: Calculate capsule or tablet loading from actual S-equol assay, premix and test uniformity and disintegration. Predefine individual skin endpoints rather than claiming broad improvement.
Evidence scope: Study amounts are not general intake recommendations; chemical and chiral purity are different measurements.
2012 · Oyama et al. · DOI 10.1097/gme.0b013e318227427b ↗Calcium, vitamin D and S-equol offer distinct ingredient modules; high mineral loading and low active loading require careful uniformity control.
Show research and formulation insights +Hide details −Combination / selection rationale: Calcium, vitamin D and S-equol offer distinct ingredient modules; high mineral loading and low active loading require careful uniformity control.
Published evidence / source details: The cited S-equol trial did not test the calcium/vitamin-D combination; it informs material selection without demonstrating blend synergy.
Development insights: Premix vitamin D and S-equol separately before mineral incorporation. Check density-driven segregation, tablet mass and disintegration; report S-equol, elemental calcium and vitamin D separately.
Evidence scope: Development concept, not a validated clinical combination.
2012 · Related material reference: natural S-equol trial ↗Literature-Supported Research Directions
In a randomized, double-blind, placebo-controlled study of postmenopausal equol non-producers, 12 weeks of 10 mg/day natural S-equol was associated with reductions in hot-flush frequency and neck or shoulder muscle stiffness.
Citation: Takeshi Aso et al., Journal of Women's Health (2012) 21(1): 92–100. DOI: 10.1089/jwh.2011.2753. PMID: 21992596.View source
A small randomized placebo-controlled study observed reduced crow’s-feet wrinkle area after 12 weeks of 10 or 30 mg/day natural S-equol in postmenopausal women; the finding is specific to the studied population and oral supplementation context.
Citation: Oyama et al., Menopause (2012): natural S-equol and skin aging in postmenopausal women.View source
In a one-year randomized controlled study, 10 mg/day S-equol was associated with reduced urinary deoxypyridinoline and prevention of whole-body bone mineral density decline, supporting further research in women’s health and bone metabolism.
Citation: Tousen et al., Menopause (2011): natural S-equol and bone resorption in postmenopausal women.View source
Note: For ingredient R&D and scientific information; findings depend on model, dose, formulation and population and do not constitute a treatment claim or efficacy guarantee.
Lead Time
3–5business days
Standard products are generally in stock; confirm the exact lead time with us.
Minimum Order
100 g
Samples, pilot trials, and commercial volumes are supported.
Foil Pouch
Sealed, moisture-protective inner packaging
Fiber Drum
Standard outer packaging for bulk transport
Bulk Shipping
Palletized and stretch-wrapped for protection
Ambient storage: foil pouch + fiber drum; temperature controlled: foil pouch + insulated box/carton. Confirm by product.
Custom packaging: Custom foil bags or HDPE drums, GMP label printing, and export documentation are available. Contact us for a quote.Images are packaging illustrations.
Certifications
Substrate Preparation
Food-grade daidzein, extracted and purified from soybean isoflavone concentrate, is prepared as the starting substrate for bioconversion.
Biocatalyst Strain Fermentation
An engineered microorganism 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.
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.
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.
PathGene supplies S-Equol powder, CAS 531-95-3, with a purity specification of ≥98.0%. Equol alone does not specify stereochemistry. Orders should identify S-Equol and review chemical purity separately from stereochemical evidence; an ordinary HPLC purity result does not replace an enantiomer-ratio measurement.
Request the chemical-purity or assay method and the separate stereochemical method and result for the same sample or lot. Ordinary HPLC purity and optical rotation should not be presented as a quantified S/R ratio without a suitable validated method. Use the quality-documents section to request matching evidence.
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.
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.
Yes, small trial samples are available for formulation testing and internal quality verification prior to committing to a bulk purchase order.
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.
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).
S-Equol powder pack options are 100 g, 500 g, 1 kg. Special inner-packaging, labeling and transport requirements are agreed separately for the order.
S-Equol powder has a 100 g MOQ, with 100 g, 500 g and 1 kg pack options. Qualification should consider chemical purity, S-configuration documentation, and dispersion and stability in the intended format.
A named S-Equol powder and a carrier-based premix are different purchasing specifications. For this ≥98% powder, use the S-Equol identity and lot COA; do not assume a particular carrier is present. A premix request must separately define S-Equol content, carrier composition, chemical purity and the relevant stereochemical evidence. Fermentation source information does not identify the composition of a finished premix.
Chemical purity measures the material against a specified analytical method; chiral analysis distinguishes S-equol from R-equol. The ≥98.0% product purity specification does not by itself establish a ≥98.0% enantiomeric result. Match the S-form identity, analytical method and lot COA when comparing suppliers.
Documents are subject to product and batch availability; third-party reports are provided only when applicable.
Quality documents
The specification sheet defines acceptance limits. The COA shows actual batch results, which may vary by batch. Third-party reports are provided only for products or batches that have been independently tested.
Stable acceptance criteria · Available on request
Actual test data · Check the COA for the applicable batch
Independent test record · Available by product/batch
Technical Resources
S-Equol is not a generic synonym for equol. This buyer guide explains stereochemical identity, chiral purity, assay interpretation, storage and the batch documents needed before approving a bulk ingredient.
A sourcing guide to S-Equol identity, engineered-microorganism bioconversion, chemical and optical purity, batch documentation, and formulation review.
Related Products
Spermidine Trihydrochloride Powder
Pyrroloquinoline Quinone Disodium Salt Powder
Interested in S-Equol?
Our R&D team will respond to your inquiry or sample request within 24 hours.
Scan to add WeChat
Alex Huang · Mon–Fri 9am–6pm CST
