L-5-MTHF
Calcium L-5-Methyltetrahydrofolate
Key Specifications
| CAS Number | 151533-22-1 |
| Purity | ≥97.0% |
| Molecular Formula | C₂₀H₂₃CaN₇O₆ |
| Molecular Weight | 497.54 g/mol |
| Appearance | Light yellow powder |
| Solubility | Soluble in water |
| Storage | 2–8°C, protect from light and moisture |
| Shelf Life | 24 months |
CAS 151533-22-1
What Is L-5-MTHF?
Calcium L-5-methyltetrahydrofolate (L-5-MTHF, CAS 151533-22-1) is the calcium salt of (6S)-5-methyltetrahydrofolic acid, the principal biologically active form of folate (vitamin B9) that circulates naturally in human blood and occurs in leafy vegetables, legumes and liver. Unlike synthetic folic acid, L-5-MTHF is the form the body uses directly in one-carbon metabolism without requiring conversion by the MTHFR enzyme. With molecular formula C20H23CaN7O6 and molecular weight 497.54 g/mol, it appears as a light yellow powder. Commercial bulk material is typically produced via a biosynthesis-based route: a tetrahydrofolate precursor is generated by microbial fermentation or controlled reduction of folic acid, then stereoselectively methylated under enzymatic catalysis (mirroring the natural methylenetetrahydrofolate reductase reaction) to yield the active (6S) isomer, followed by calcium salt formation, crystallization and purification to pharmaceutical-grade purity.
Other Names
Key Features
High-Purity Active Folate
Assayed at ≥97.0% purity by validated HPLC methods, with each batch supported by an EP/ISO-compliant certificate of analysis.
Controlled Biosynthetic Production
Produced via an enzymatic, stereoselective methylation process that tightly controls (6S) isomer content and minimizes process-related impurities batch to batch.
Consistent Light Yellow Powder
Delivered as a free-flowing, uniform light yellow powder with consistent particle size for reliable handling and dosing in downstream formulations.
Rigorous Contaminant Screening
Every batch is screened for heavy metals (Pb, As, Hg, Cd) and microbial limits, ensuring compliance with pharmaceutical and food-grade raw material requirements.
Flexible Bulk & OEM Supply
Available in flexible bulk quantities with OEM/private-label packaging, custom blending and documentation support for supplement, pharma and food fortification customers.
| Molecular Formula | C₂₀H₂₃CaN₇O₆ |
| Molecular Weight | 497.54 g/mol |
| Appearance | Light yellow powder |
| Solubility | Soluble in water |
| Storage Condition | 2–8°C, protect from light and moisture |
| Shelf Life | 24 months |
| Grade 1 | Pharmaceutical Grade · ≥97.0% · EP |
End-Product Applications
Mechanism & Benefits
Bioactive folate form. Participates in nucleic acid synthesis, prevents folate deficiency, supports fetal development.
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
EP
European Pharmacopoeia
ISO
ISO
Manufacturing Process
Microbial Fermentation / Precursor Generation
An engineered microbial strain (or a controlled chemical reduction step starting from folic acid) generates the dihydrofolate/tetrahydrofolate precursor required for downstream biocatalytic conversion.
Enzymatic Reduction to Tetrahydrofolate
The precursor is enzymatically reduced to tetrahydrofolate (THF) under controlled temperature, pH and cofactor supply, establishing the reduced folate backbone.
Stereoselective Enzymatic Methylation
A methylenetetrahydrofolate reductase (MTHFR)-type biocatalyst introduces the methyl group at the N5 position with high stereoselectivity, yielding the active L-5-MTHF (6S) free acid.
Cell Separation and Clarification
Biomass and cellular debris are removed by filtration/centrifugation, and the clarified fermentation broth is concentrated for further processing.
Chromatographic Purification
The concentrate undergoes chromatographic purification to remove residual isomers, unreacted precursors and process-related impurities, enriching the target L-5-MTHF.
Calcium Salt Formation
Purified L-5-MTHF free acid is converted to its calcium salt under controlled pH and stoichiometry, improving stability for downstream isolation.
Crystallization and Drying
The calcium salt is crystallized from aqueous solution under light-protected, low-oxygen conditions, then dried under controlled temperature to preserve chemical integrity.
Milling, QC Release and Packaging
The dried crystals are milled and sieved to the target particle size, tested against full release specifications, then packaged under nitrogen/light-protected conditions.
Quality Specifications
| Test Item | Specification | Result |
|---|---|---|
| Appearance | Light yellow powder | Light yellow powder, complies |
| Odor | Odorless or faint characteristic odor | Complies |
| Assay (HPLC, on dried basis) | ≥97.0% | 98.2% |
| Identification (UV/IR) | Conforms to reference spectrum | Conforms |
| Specific Rotation [α]D20 (c=1, H2O) | +12° to +18° | +15.4° |
| Particle Size (through 80 mesh) | ≥95% | 98% |
| Loss on Drying | ≤8.0% | 5.8% |
| Lead (Pb) | ≤10 ppm | <5 ppm |
| Arsenic (As) | ≤2 ppm | <1 ppm |
| Mercury (Hg) | ≤1 ppm | <0.5 ppm |
| Cadmium (Cd) | ≤1 ppm | <0.5 ppm |
| Total Plate Count | ≤1000 CFU/g | <100 CFU/g |
| Yeast & Mold | ≤100 CFU/g | <10 CFU/g |
| E. coli / Salmonella | Negative/25 g | Negative |
Purity & Assay Method
Purity is determined by reversed-phase HPLC against a reference standard, quantifying the L-5-MTHF calcium content on a dried basis while resolving related folate isomers and degradation products. Because 5-methyltetrahydrofolate is light- and oxygen-sensitive, buyers should confirm the batch-specific certificate of analysis, the chiral (6S) purity, storage conditions used prior to shipment, and request a retention/stability statement when placing bulk orders.
Solubility & Formulation
L-5-MTHF calcium is soluble in water, allowing incorporation into aqueous premixes, effervescent formats, oral liquids and soft-gel fill solutions in addition to standard tablet and capsule matrices. Because the compound is sensitive to light, heat, oxygen and low pH, formulators should use light-protective packaging, inert-atmosphere processing where feasible, and mildly buffered aqueous systems to maintain potency through shelf life; compatibility and accelerated-stability testing in the target matrix is recommended before scale-up.
Available Product Forms
Bulk L-5-MTHF Powder
High-purity raw powder for supplement factories, research organizations, ingredient distributors, and contract manufacturers.
L-5-MTHF Capsules
Custom capsule strength, shell material, bottle count, excipients, and label design for private-label brands.
L-5-MTHF Tablets
Tablet formulation, granulation, compression, coating, bottle packaging, and custom labeling support.
L-5-MTHF Powder Blends
L-5-MTHF can be blended with complementary actives (antioxidants, other longevity ingredients, vitamins, minerals) per customer formula.
What purity level does your L-5-MTHF calcium meet, and can you provide a certificate of analysis?+
Our standard grade is assayed at ≥97.0% purity by HPLC, certified to EP and ISO requirements. A batch-specific certificate of analysis, including heavy metal and microbial results, is provided with every shipment and can be sent in advance for review.
How is this ingredient manufactured — fermentation, enzymatic conversion, or chemical synthesis?+
It is produced via a biosynthesis-based route: a tetrahydrofolate precursor is generated by microbial fermentation or controlled reduction, then converted to the active (6S) isomer through enzymatic, stereoselective methylation, followed by calcium salt formation, crystallization and purification.
What is the solubility of this product, and how should it be formulated?+
L-5-MTHF calcium is soluble in water and can be used in tablets, capsules, oral liquids and premixes. Due to its sensitivity to light, oxygen and low pH, light-protective packaging and mildly buffered aqueous systems are recommended.
Can we request a sample before placing a bulk order?+
Yes, small evaluation samples with an accompanying certificate of analysis are available on request so you can verify purity, appearance and compatibility before committing to a bulk purchase.
Do you support third-party testing or independent verification of specifications?+
Yes, customers are welcome to send samples to an independent laboratory of their choice for verification, and we can coordinate additional testing (e.g., residual solvents, chiral purity) on request.
Do you offer OEM or private-label options?+
Yes, we support OEM/private-label packaging, custom blending with other actives or excipients, and documentation support (specifications, CoA templates, regulatory dossiers) tailored to your brand requirements.
What packaging options are available?+
Standard packaging includes light-protective aluminum foil bags or fiber drums in 1 kg, 5 kg and 25 kg units, typically with nitrogen flushing and desiccant; custom packaging sizes can be arranged for larger contracts.
What is the minimum order quantity (MOQ) and how do we get a quotation?+
MOQ is typically 1 kg for trial/sample orders, with tiered pricing for larger bulk quantities. Please share your target quantity, intended application and delivery destination so we can prepare a formal quotation.
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
L-5-MTHF
CAS No.
151533-22-1
Batch No.
PG-SAMPLE-000000
Packaging
Issued upon order confirmation
| Test Item | Specification | Result |
|---|---|---|
| Appearance | Light yellow powder | Light yellow powder, complies |
| Odor | Odorless or faint characteristic odor | Complies |
| Assay (HPLC, on dried basis) | ≥97.0% | 98.2% |
| Identification (UV/IR) | Conforms to reference spectrum | Conforms |
| Specific Rotation [α]D20 (c=1, H2O) | +12° to +18° | +15.4° |
| Particle Size (through 80 mesh) | ≥95% | 98% |
| Loss on Drying | ≤8.0% | 5.8% |
| Lead (Pb) | ≤10 ppm | <5 ppm |
| Arsenic (As) | ≤2 ppm | <1 ppm |
| Mercury (Hg) | ≤1 ppm | <0.5 ppm |
| Cadmium (Cd) | ≤1 ppm | <0.5 ppm |
| Total Plate Count | ≤1000 CFU/g | <100 CFU/g |
| Yeast & Mold | ≤100 CFU/g | <10 CFU/g |
| E. coli / Salmonella | Negative/25 g | 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.
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