AKG-Ca
CAS 71686-01-6
Purity≥98.0%
Calcium alpha-ketoglutarate for mineral and nutrition formulations
For B2B ingredient sourcing, request the specification, batch COA, sample, packaging and lead-time confirmation. Explore healthy-aging ingredients.
Confirm calcium contribution and alpha-ketoglutarate assay basis.
Key Specifications
| Product Positioning | Calcium alpha-ketoglutarate for mineral and nutrition formulations |
| Application Scenarios | calcium nutrition formulas · mineral premix development · alpha-ketoglutarate research |
| CAS Number | 71686-01-6 |
| Purity | ≥98.0% |
| Molecular Formula | C₅H₄CaO₅ |
| Molecular Weight | 184.16 g/mol |
| Appearance | White crystalline powder |
| Solubility | Poorly soluble in water; slightly soluble in acidic aqueous media |
| Storage | Room temperature, dry |
| Shelf Life | 24 months |
Procurement & delivery
Supply details confirmed by intended use, volume and target market
Calcium alpha-ketoglutarate (Ca-AKG, CAS 71686-01-6) is the calcium salt of alpha-ketoglutaric acid (2-oxoglutaric acid), a keto-acid intermediate of the tricarboxylic acid (TCA) cycle. With the molecular formula C5H4CaO5 and a molecular weight of 184.16 g/mol, it is supplied as a white crystalline powder. Unlike free alpha-ketoglutaric acid, AKG-Ca is poorly soluble in neutral water and only slightly soluble in acidic aqueous media. In gastric-like acidic conditions it can dissolve progressively, giving a pH-dependent and comparatively slower dissolution profile; the actual release rate still depends on particle size, crystal form, agitation and the finished dosage form. Commercial bulk material is generally produced by fermentation or enzymatic bioconversion to obtain the free acid, followed by purification, neutralization with a food-grade calcium base, crystallization, drying and milling.
| Comparison | AKG-Ca (Calcium Salt) | Alpha-Ketoglutaric Acid (Free Acid) |
|---|---|---|
| Chemical form | Calcium salt of alpha-ketoglutarate; contains a calcium counter-ion. | Free dicarboxylic acid; does not contain calcium. |
| Water solubility | Poorly soluble in neutral water; only slightly soluble in acidic aqueous media. | Markedly more water-soluble and easier to prepare as an aqueous solution. |
| pH and dissolution | Dissolves progressively as pH decreases; may show comparatively slower, pH-dependent gastric-stage dissolution. | Dissolves faster but forms an acidic solution that may require pH and taste adjustment. |
| Calcium contribution | Contributes calcium; calcium content and hydration state should be confirmed on the batch specification. | No calcium contribution. |
| Typical formulation fit | Usually better suited to capsules, tablets and other solid formats where gradual dissolution can be evaluated. | Better suited to aqueous liquids, drink powders and fast-dissolving systems when acidity is properly managed. |
| Procurement check | Confirm CAS, hydration state, calcium assay, particle size and dissolution method. | Confirm free-acid assay, water, acidity, solution pH and stability. |
AKG-Ca and free AKG acid are not interchangeable on an equal-mass basis. A slower raw-material dissolution rate does not by itself establish a sustained-release claim; the finished product requires a defined dissolution method and supporting test data.
Verified High Purity (≥98.0%)
Each batch is assayed by HPLC to confirm alpha-ketoglutarate content meets or exceeds 98.0%, giving formulators a consistent, well-characterized active ingredient.
Controlled Bioconversion & Traceable Inputs
Produced on a synthetic-biology and enzymatic conversion platform with defined feedstocks and in-process controls, supporting batch-to-batch consistency and full raw-material traceability.
pH-Dependent Dissolution Profile
Poorly soluble in neutral water and only slightly soluble in acidic aqueous media, AKG-Ca dissolves progressively under gastric-like acidic conditions. Particle size and the finished dosage form should be evaluated when defining the target dissolution profile.
Comprehensive Contaminant Testing
Every lot is screened for heavy metals (Pb, As, Hg, Cd) and microbial limits, with results documented on a certificate of analysis for each shipment.
Flexible Bulk Supply & OEM Support
Available in bulk quantities with flexible packaging, custom particle size, and OEM/private-label formatting to fit finished-product manufacturers' specifications.
Test items, specifications and batch results are shown here; request the formal COA through the card below.
Batch No.
PGAKG-260314
Test date
2026-03-15
Specification
In-house
Pack size
25 kg/carton
Storage
Room temperature, dry
Conclusion
Conforms
| Test Item | Specification | Result |
|---|---|---|
| Appearance | White to off-white powder | Off-White Powder |
| Identification | Assay peak retention time identical to standard | Complies |
| Purity | ≥98% | 99.8% |
| Calcium (dry basis) | 18–23% | 19.2% |
| Assay | 98.0%–102% | 100.4% |
| Loss on drying | ≤3.0% | 0.36% |
| pH | 6.0–8.0 | 6.73 |
| Lead (Pb) | ≤0.1 ppm | Complies |
| Mercury (Hg) | ≤0.1 ppm | Complies |
| Cadmium (Cd) | ≤0.2 ppm | Complies |
| Arsenic (As) | ≤0.1 ppm | Complies |
| Total microbial count | ≤1000 CFU/g | Complies |
| Coliform | ≤0.92 MPN/g | Complies |
| Mold and yeast | ≤100 CFU/g | Complies |
| Staphylococcus aureus | 0/25 g | Complies |
| Salmonella | 0/25 g | Complies |
| Bulk density | — | 0.38 g/ml |
This page shows a batch-data summary only. No direct COA file link is provided; request the signed document through the form below.
Hard capsules
Powders
Softgels
Tablets
Sublingual tablets
Oral dissolving films
Calcium alpha-ketoglutarate has been studied in bone and aging-related nutrition. It can be evaluated with collagen peptides and vitamin D in a bone-health formulation, with calcium contribution and total intake controlled during development.
Evidence: Indirect evidence: human Ca-AKG studies and separate calcium/vitamin D/collagen research; no direct Ca-AKG multi-ingredient synergy trial confirmed.Source
Literature-Supported Research Directions
In a six-month randomized study of postmenopausal women with osteopenia, calcium alpha-ketoglutarate was associated with lower serum CTX and a small, non-significant change in bone mineral density versus calcium alone. Long-term effects require further study.
Citation: Brun et al., Nutrition (2008): calcium alpha-ketoglutarate and bone-remodeling biomarkers.View source
AKG is a tricarboxylic-acid-cycle intermediate linked to amino-acid metabolism and collagen-related substrate supply. Calcium salt formulation development should separately evaluate mineral contribution, acid solubility, release behavior and gastrointestinal tolerance.
Citation: Brun et al., Nutrition (2008); product-specific formulation properties require independent testing.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
1 kg
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
Strain & Feedstock Preparation
An engineered production strain and a low-cost carbon source (e.g., glucose or glycerol) are prepared under controlled conditions to seed the fermentation stage.
Fermentation / Enzymatic Bioconversion
The strain is cultivated in a fed-batch bioreactor with monitored pH, dissolved oxygen, and temperature, converting the carbon source into alpha-ketoglutaric acid via microbial metabolism or biocatalytic conversion.
Biomass Removal
The fermentation broth is clarified by centrifugation and/or membrane filtration to remove cell mass and coarse solids, yielding a clear alpha-ketoglutarate-rich liquor.
Purification & Decolorization
Ion-exchange chromatography and activated-carbon treatment remove residual proteins, salts, and pigments to concentrate and purify the alpha-ketoglutaric acid intermediate.
Neutralization / Salt Formation
The purified free acid is reacted with a food/pharmaceutical-grade calcium base (calcium hydroxide or calcium carbonate) under controlled pH to form calcium alpha-ketoglutarate before crystallization.
Crystallization & Isolation
Controlled cooling and evaporative crystallization precipitate calcium alpha-ketoglutarate crystals, which are then separated from the mother liquor by filtration or centrifugation.
Drying & Milling
The isolated crystals are dried under vacuum or in a controlled-humidity dryer, then milled and sieved to achieve the target particle size and free-flowing powder form.
Quality Control & Packaging
Finished powder is tested against full specifications (assay, heavy metals, microbial limits) and packaged in moisture-protective containers under quality-controlled conditions.
Purity is determined by high-performance liquid chromatography (HPLC) against a reference standard, which quantifies alpha-ketoglutarate content independent of moisture or minor salt-form variation. Buyers should request the current certificate of analysis for each lot and confirm the assay method, reference standard, and acceptance range specified in the purchase agreement, as well as whether results are reported on an as-is or dried basis.
AKG-Ca is poorly soluble in neutral water and should not be described as a freely water-soluble ingredient. It is only slightly soluble in acidic aqueous media and dissolves progressively as pH decreases. This pH-dependent behavior can produce comparatively slower dissolution during the gastric stage than free alpha-ketoglutaric acid, but it is not equivalent to a validated controlled-release or sustained-release dosage form. Capsules and tablets are generally more suitable than clear beverages or other fully aqueous formats. Formulators should verify dissolution using the actual particle size, crystal form, excipient system and finished dosage form; micronization may improve dispersion but does not change the compound's intrinsic aqueous solubility.
Each production lot is tested in-house against our full specification (assay, appearance, heavy metals, microbial limits) using HPLC and standard analytical methods, and a certificate of analysis is issued with every shipment.
The alpha-ketoglutarate intermediate is generated through microbial fermentation or enzymatic bioconversion of low-cost carbon sources on our synthetic-biology production platform, then purified and neutralized with a food-grade calcium base to form the crystalline calcium salt — it is not derived from plant extraction.
No. AKG-Ca is poorly soluble in neutral water and only slightly soluble in acidic aqueous media. Under gastric-like acidic conditions it dissolves progressively, and the observed rate depends on pH, particle size, temperature, agitation and the finished dosage form. This can create comparatively slower gastric-stage dissolution than free AKG acid, but it should not be marketed as a controlled- or sustained-release product without finished-product dissolution data.
AKG-Ca is the calcium salt: it contains calcium, is poorly soluble in neutral water and shows pH-dependent gradual dissolution in acidic media. Free AKG acid contains no calcium, is markedly more water-soluble and dissolves faster, but produces a more acidic solution that may require pH and taste adjustment. They differ in molecular weight, calcium contribution and formulation behavior, so they should not be substituted on an equal-mass basis.
Yes, samples are available for evaluation upon request so you can verify appearance, solubility, and quality against your internal specifications before committing to a bulk purchase.
Yes, in addition to our internal certificate of analysis, buyers are welcome to submit samples to an independent laboratory of their choice for third-party verification of purity, heavy metals, and microbial limits.
Yes, we support OEM and private-label arrangements, including custom packaging, labeling, and formulation assistance for finished-product brands sourcing this ingredient.
Standard bulk packaging is typically supplied in moisture-protective drums or bags (e.g., 25 kg units), with custom packaging sizes and formats available on request to suit different order volumes.
Minimum order quantity and pricing depend on packaging format and order volume; please contact our sales team with your target quantity and application to receive a formal quotation and lead time.
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 · Issued with each shipment
Independent test record · Available by product/batch
Technical Resources
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