Sample Available

Ca-AKG

CAS 71686-01-6

Calcium Alpha-Ketoglutarate Powder

Name: Calcium Alpha-Ketoglutarate Powder
Brand: PathGene

Purity≥98.0%

Calcium alpha-ketoglutarate for mineral and nutrition formulations

Calcium Alpha-Ketoglutarate Powder (CAS 71686-01-6), specification ≥98.0%. The calcium salt of alpha-ketoglutarate; free-acid AKG is listed as a separate ingredient with its own specification. Batch COA and evaluation samples are available. MOQ: 1 kg. healthy-aging ingredients

Quote / sample & delivery

MW184.16 g/mol

Calcium Alpha-Ketoglutarate Powder (CAS 71686-01-6) bulk active ingredient

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

Purity ≥98.0%CAS 71686-01-6

MOQ1 kg

Lead Time3–5 business days

Packaging1 kg / 5 kg / 25 kg

Free sample available

View quality documents ↓

What Is Ca-AKG?

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.

Other Names

Calcium 2-oxoglutarateCalcium 2-oxopentanedioateCa-AKGCalcium oxoglutarate2-Oxoglutaric acid calcium saltCalcium alpha-ketoglutarateCAS 71686-01-6

AKG-Ca vs Alpha-Ketoglutaric Acid (Free Acid)

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.

Key Features

🔬

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.

🧬

Ingredient Identity

The calcium salt of alpha-ketoglutarate; free-acid AKG is listed as a separate ingredient with its own specification.

⚪

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.

Recent batch test data

Test items, specifications and results for the listed batch are shown here. View or request a COA in the quality documents section.

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

View an available COA in the quality documents section. Check the document for its product form and batch; request a signed COA for your purchasing or shipment batch separately.

Applicable Dosage Forms

Hard capsules

Powder and functional beverage formulation

Powders

Softgels

Tablets

Sublingual tablets

Oral dissolving films

Ca-AKG development essentials

Calculate calcium-salt mass, AKG moiety and calcium contribution separately; do not transplant free-acid recipes.

99.8%

Purity

100.4%

Assay

PGAKG-260314 · Results apply to this lot; interpret purity, assay and water on their respective bases.

Composition candidates:: Compare flow/compressibility for solids; use powder carriers with collagen and preblend low-loading vitamin D.
Processing priorities:: Track pH/caking after contact with acidic excipients; assess taste and settling in reconstituted samples.
Testing priorities:: AKG assay, calcium, water, compression and disintegration; qualify the AKG form used in cited studies.

Review lot COA ↗Explore formulation and combination research ↓

Ca-AKG formulation development: composition, processing and validation

Composition candidates, processing sequences and tests support pilot design. Confirm candidate excipients and processes using this material in the actual finished formulation.

Solid formats: carriers, loading and mixing

Define loading by ingredient mass, salt mass or active moiety. Use m = target mass / assay as supplied only when both share the same basis; convert dried-basis assays using water where appropriate, and do not substitute HPLC area purity for mass assay. Set excipient amounts from fill mass, bulk density and uniformity trials.
Compare flow/compressibility for solids; use powder carriers with collagen and preblend low-loading vitamin D.
Record ingredient lots, actual component masses, loading bases and addition sequence, retaining blanks and single-ingredient controls for traceable changes.

Processing and formats: pilot batches through filling

Track pH/caking after contact with acidic excipients; assess taste and settling in reconstituted samples.
Select blending/filling equipment for the actual format, recording size, bulk density, mixing time and fill mass; liquid or softgel routes need separate carrier, sedimentation and container/shell compatibility testing.

Validation and scale-up: tests, retained samples and packaging

AKG assay, calcium, water, compression and disintegration; qualify the AKG form used in cited studies.
Sample upper/middle/lower positions and start/middle/end filling; compare with ingredients, process blanks and single-ingredient results, documenting deviations and corrections.
Include actual packaging, transport and intended storage in retained-sample plans; ingredient COAs and storage conditions do not establish a new finished-product shelf life.

Literature-informed combinations and development insights

Application examples follow the materials, formats and findings actually studied. Combination studies, single-ingredient studies, commercial precedents and development candidates are distinguished.

Single-ingredient and standardized-material applications

Human application of the calcium salt

Ca-AKG: separate AKG and calcium reporting in a human study

Ca-AKG supplies both an AKG moiety and calcium; procurement and loading require more than total salt mass.

Show research and formulation insights +

Combination / selection rationale: Ca-AKG supplies both an AKG moiety and calcium; procurement and loading require more than total salt mass.

Published evidence / source details: A six-month 2007 trial in 76 postmenopausal women supplied 6 g AKG and 1.68 g calcium daily via the salt, against equal calcium. CTX differed between groups; BMD change did not significantly differ.

Development insights: Specify assay basis, target AKG, calcium and water basis separately before conversion. Test fill mass, compressibility and disintegration for solids, or pH and settling for reconstituted formats.

Evidence scope: Reported moiety amounts are not total salt mass or intake advice, and do not establish an antiaging guarantee.

2007 · Filip et al. · DOI 10.1024/0300-9831.77.2.89 ↗

Formulation development candidates

Formulation development candidate

Ca-AKG + collagen / vitamin D: loading and mineral contribution

Collagen peptides, calcium salt and low-level vitamin D have different loading requirements, suggesting sachet, tablet and separate-format screens.

Show research and formulation insights +

Combination / selection rationale: Collagen peptides, calcium salt and low-level vitamin D have different loading requirements, suggesting sachet, tablet and separate-format screens.

Published evidence / source details: The Ca-AKG trial provides salt-specific context and endpoints, not evidence for this exact collagen/vitamin-D blend.

Development insights: Premix vitamin D before staged salt/collagen blending. Sum elemental calcium from all sources and assay AKG, calcium and vitamin D separately; assess taste, haze, caking or tablet size and disintegration.

Evidence scope: Blend-development candidate, not a validated combination from the calcium-salt trial.

Manufacturing Process

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 & Assay Method

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.

Solubility & Formulation

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.

How is the purity and specification of each batch confirmed?+

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.

How is this ingredient produced, and where does the raw material come from?+

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.

How does calcium AKG powder behave in water, and what should formulators test?+

Calcium AKG powder has limited solubility in neutral water, with dissolution under acidic conditions affected by pH, particle size, temperature and mixing. Evaluate dispersion, sedimentation and dissolution for the intended format. Sustained- or controlled-release claims require supporting finished-product dissolution data.

What is the difference between AKG-Ca and alpha-ketoglutaric acid (AKG acid)?+

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.

Can we request a sample before placing a bulk order?+

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.

Do you support third-party testing of the product?+

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.

Do you offer OEM or private-label services?+

Yes, we support OEM and private-label arrangements, including custom packaging, labeling, and formulation assistance for finished-product brands sourcing this ingredient.

Which pack sizes are available for calcium AKG powder?+

Calcium AKG powder pack options are 1 kg, 5 kg, 25 kg. Special inner-packaging, labeling and transport requirements are agreed separately for the order.

What are the MOQ and pack options for calcium AKG powder?+

The raw-material MOQ for calcium AKG powder is 1 kg, with pack options of 1 kg, 5 kg, 25 kg. Typical lead time is 3–5 business days, with dispatch confirmed for the order.

How should Ca-AKG loading and calcium contribution be calculated?+

Define whether the target refers to calcium-salt mass, the AKG moiety or elemental calcium. Use the supplied grade composition, appropriate mass-assay basis and water correction rather than treating HPLC area purity as a mass fraction. Count calcium contributed by all other ingredients when designing a blend. Ca-AKG and alpha-ketoglutaric acid are separate materials.

Why Choose PathGene

Direct China manufacturer supply — factory pricing, no middleman
Recent-batch COA & batch traceability
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 testing support available on request

Documents Available

·Product specification sheet — request from sales
·Recent-batch COA — confirm by product and batch
·Other quality documents — confirm by product and batch

Documents are subject to product and batch availability; third-party reports are provided only when applicable.

Quality documents

Review specifications first, then batch data at shipment

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.

Product specification

Stable acceptance criteria · Available on request

Recent-batch COA

Actual test data · Check the COA for the applicable batch

View COA online

Third-party test report

Independent test record · Available by product/batch

Technical Resources

Ca-AKG Technical Articles

View all articles →

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What Is Ca-AKG?

AKG-Ca vs Alpha-Ketoglutaric Acid (Free Acid)

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.

Key Features

🔬

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.

🧬

Ingredient Identity

The calcium salt of alpha-ketoglutarate; free-acid AKG is listed as a separate ingredient with its own specification.

⚪

pH-Dependent 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.

Why Choose PathGene

Direct China manufacturer supply — factory pricing, no middleman

Recent-batch COA & batch traceability

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

Calcium Alpha-Ketoglutarate Powder

What Is Ca-AKG?

Other Names

AKG-Ca vs Alpha-Ketoglutaric Acid (Free Acid)