L-Lactic acid-2-¹³C - ≥99 atom% 13C,≥98%,≥98%(Chiral Purity,HPLC)

Cat. No.: L465454

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Specifications

Specifiche e purezza

≥99 atom% 13C,≥98%,≥98%(Chiral Purity,HPLC)

Condizioni di conservazione di stoccaggio

Store at -20°C

Spedito in

Ice chest + Ice pads

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Application Protocols

Not applicable (no immunoassay/antibody validations provided).

• This small-molecule standard does not have WB/IHC/IF/FC protocols associated. For use as an analytical standard or tracer:
  • LC–MS internal standard (general): prepare a stock (e.g., 1–10 mM) in water or 50:50 water:methanol; spike samples at a constant concentration; use isotopologue dilution for quantitation. Optimize concentration for your instrument; verify linear range.
  • ¹³C NMR: dissolve in D2O (adjust pD) or DMSO-d6; acquire with ¹H decoupling to emphasize the labeled C2 signal. Reference chemical shifts appropriately. These are general literature practices and not item-specific recommendations; adjust to your method and consult the CoA/SDS.

Biological Roles

General biochemical context (no medical claims)

• Central metabolite: L-lactate is the end product of lactate dehydrogenase (LDH) reduction of pyruvate, regenerating NAD⁺ during glycolysis under hypoxic or high-flux conditions.
• Shuttle and recycling: participates in the Cori cycle—export from glycolytic tissues and reconversion to glucose in gluconeogenic tissues. Also involved in lactate shuttles between cells and organelles.
• Acid-base balance: contributes to extracellular acidification; lactate/lactic acid interconversion buffers in the pH 3–5 regime locally, while systemic buffering involves bicarbonate (outside scope here).
• Signaling roles: lactate can modulate enzyme activities and act via receptor-mediated pathways in research models; 2-¹³C labeling allows tracking of pool sizes and exchange rates.

Isotope tracing value (specific to 2-¹³C)

• Position-specific information: Label at C2 enables distinction between symmetric scrambling vs. directed conversions (e.g., to alanine via transamination of 2-¹³C-pyruvate).
• Analytical advantages: enhanced ¹³C NMR signal at the alpha-carbon; predictable +1 m/z shift in MS for fragments retaining C2, facilitating isotopomer mapping.

Practical considerations

• Maintain physiological relevance by controlling pH and ionic strength in assay buffers; lactate speciation (acid vs. lactate) affects transporter uptake and enzyme kinetics.
• For quantitative fluxomics, pair 2-¹³C-lactate with complementary tracers (e.g., U-¹³C-glucose) to resolve network redundancies.

Buffer Applications

Applicability

• While isotopically labeled lactic acid is rarely used to prepare routine buffers due to cost, the lactate/lactic acid system is relevant in analytical and biochemical settings.

General guidance (literature)

• pKa (25°C): ~3.86 (carboxyl). Effective buffering range is roughly pH 2.9–4.9.
• Buffer preparation: adjust aqueous lactic acid with NaOH or KOH to the desired pH to form the corresponding lactate. Ionic strength can be tuned with inert salts (e.g., NaCl) if needed.
• Compatibility: lactate buffers are compatible with many enzymes active in mildly acidic conditions, but activity of most mammalian enzymes peaks near neutral pH; verify enzyme-specific tolerance.
• Ionic form: at pH above ~5, lactate predominates; transporters and assays that are anion-selective may require this pH regime.

Isotope-specific note

• If using 2-¹³C-lactic acid in buffer for tracer work, prepare fresh, record exact pH, and confirm isotopic enrichment pre-/post-use by MS when high-precision mass balance is required.

Green Alternatives

Context

• L-Lactic acid is bio-based (fermentation-derived) and biodegradable, making it comparatively benign. The 2-¹³C isotopologue shares these attributes, though isotopic enrichment has its own resource/energy footprint.

Greener choices and trade-offs (general)

• Unlabeled lactic acid vs 2-¹³C: For method development or non-quantitative work, unlabeled lactic acid avoids consumption of enriched material. For quantitation, the labeled isotopologue reduces sample/reagent use by improving sensitivity—an indirect green benefit.
• Lactate salts in water: Using sodium/potassium lactate minimizes use of organic solvents for aqueous workflows.
• Solvent selection: Prefer water or lower-toxicity alcohols (ethanol) for reactions/stock solutions. Avoid chlorinated solvents where possible; consider ethyl acetate or 2-MeTHF for extractions.

Small comparison (literature; illustrative)

• Water (preferred): nonflammable, minimal toxicity; may require pH adjustment to maintain solubility/speciation.
• Ethanol: bio-derived option with good solvency; flammable but lower toxicity than many organics.
• DMSO: excellent solvency; readily biodegradable but persistent odor and disposal considerations.

Operational tips

• Scale judiciously: isotopically enriched reagents are scarce; optimize on unlabeled substrates first.
• Minimize waste: run micro-scale assays (microtiter, microcoil NMR) to reduce consumption and solvent use.

Pharmaceutical Uses

Scope

• No therapeutic claims. The following summarizes formulation/manufacturing roles of lactic acid generally; isotopically labeled material is intended for research only.

General formulation roles (literature)

• pH adjustment/acidity regulator: lactic acid is used to acidify aqueous formulations and to adjust microenvironmental pH in topical/oral products.
• Solubilization: formation of lactate salts can improve solubility of basic APIs; lactic acid can assist in salt screening.
• Polymer precursor: lactide/PLA derived from lactic acid is used in biomedical devices (e.g., resorbable materials); labeling may be used in research on degradation pathways, not in marketed products.

Regulatory/compendial

• Lactic acid appears in pharmacopoeias (e.g., USP/Ph.Eur.) with specifications on assay, impurities, and optical rotation; none of these pharmacopeial specifications apply to this labeled research item unless explicitly stated in the CoA.

Isotope-specific remark

• 2-¹³C-lactic acid is used in development and analytical method validation (e.g., internal standards) rather than as an excipient in commercial drug products.

Physical Properties

Item-specific facts (from Product Data)

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

Literature/general properties for lactic acid (apply equally to 2-¹³C isotopologue; values are not item specifications)

• Aggregate state: typically a viscous liquid or low-melting solid depending on hydration and enantiomeric purity (lactic acid is hygroscopic).
• pKa (carboxyl): ~3.86 at 25°C (literature).
• LogP (octanol/water): approximately −0.7 (literature), indicating high hydrophilicity.
• Solubility: miscible with water; soluble in polar organic solvents such as methanol, ethanol, acetone; limited solubility in nonpolar solvents (literature).
• Boiling behavior: tends to decompose/polymerize upon heating; reported bp around 122–125°C at reduced pressure (~15–20 mmHg) (literature). Not typically distilled at atmospheric pressure.
• Melting point: form-dependent; reported values for L-lactic acid near 53°C for anhydrous crystalline forms; commonly encountered as liquid due to hygroscopicity (literature).
• Density: ~1.20 g/mL at 20°C for concentrated solutions; pure anhydrous varies with water content (literature).
• Refractive index (nD20): ~1.43–1.44 for concentrated solutions (literature).
• Molecular weight: unlabeled lactic acid 90.08 g/mol (average). With one ¹³C, average MW ≈ 91.08 g/mol; monoisotopic exact mass increase ≈ +1.00335 u (computed/literature).

Notes

• Isotopic labeling with ¹³C does not materially change bulk physical behavior; differences are primarily in exact mass and NMR properties.

Quality and Grades

Item-specific facts (from Product Data)

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.

Guidance for this isotopically labeled reagent (general)

• Isotopic enrichment: For position-specific ¹³C reagents, the key quality attribute is atom% ¹³C at the specified position (C2) and overall ¹³C content. Enrichment directly affects sensitivity/quantitation in tracer studies. Exact enrichment for this item is not specified here—consult the CoA.
• Chemical purity vs. isotopic purity: Both matter. Chemical impurities (water, lactide, oligomers, residual solvents) can impact reactions and quantitation. Isotopic impurities (¹²C at C2 or scrambling at other carbons) dilute tracer signals.
• Chiral integrity: As an L-reagent, enantiomeric excess (ee) should be controlled. Where critical, verify ee by chiral HPLC/GC or derivatization methods. Value not specified for this item—refer to CoA.
• Trace contaminants: For NMR/MS applications, low metal/UV-absorbing impurities are preferred, but specific limits for this item are not specified.
• Stabilizers: Lactic acid typically requires no stabilizer; polymerization to lactide can occur on heating or in dehydrating conditions. No stabilizer information is specified for this item.
• Documentation: For quantitative work (e.g., isotope-dilution MS), rely on the lot-specific CoA for exact isotopic distribution, chemical assay, residual solvent/water content, and recommended analytical conditions.

Reaction and Applications

Isotope-enabled applications (general)

• Stable-isotope tracing: 2-¹³C positions the label at the chiral center, enabling pathway-resolved flux analysis in glycolysis/gluconeogenesis, the Cori cycle, and lactate-pyruvate interconversion. Positional enrichment informs ¹³C NMR and high-resolution MS isotopomer distributions.
• Quantitative standards: internal/external standard for LC–MS/GC–MS of lactic acid after derivatization (e.g., silylation or butylation). Position-specific ¹³C minimizes overlap with natural-abundance ¹³C satellites.
• NMR studies: assignment of ¹³C chemical shifts and J-couplings around the alpha-carbon; investigation of hydrogen bonding and conformational dynamics of alpha-hydroxy acids.

Synthetic and derivatization uses (general)

• Esterification to labeled lactates (methyl, ethyl, benzyl) for use as chiral auxiliaries or analytical derivatives.
• Conversion to lactyl chlorides/anhydrides followed by acyl transfer to alcohols/amines (introduces 2-¹³C lactyl motif into targets).
• Thermal dimerization to labeled lactide (precursor to PLA) under dehydrating conditions; useful for polymer labeling studies.
• Oxidation to 2-¹³C-pyruvic acid (e.g., TEMPO, hypervalent iodine) for labeled keto-acid synthesis; or reduction/derivatization to propanediols.

Practical notes

• Drying: azeotropic removal of water or use of molecular sieves improves esterification/activation.
• Avoid racemization: conduct coupling below ambient temperatures and with mild activators (e.g., EDC/DMAP) to preserve L-configuration.
• Analytical: verify isotopic integrity by ¹³C NMR (enhanced alpha-carbon signal) and HRMS (M+1 exact mass shift).

Reaction Conditions

General conditions (literature; illustrative, not item specifications)

• Fischer esterification: lactic acid (2-¹³C) with ROH (3–10 equiv), catalytic H2SO4 or TsOH (1–5 mol%), Dean–Stark or molecular sieves; 40–80°C (MeOH/EtOH) to reflux; hours to overnight. Monitor to avoid racemization and oligomerization.
• Carbodiimide coupling: EDC (1.1–1.5 equiv) with catalytic DMAP in DCM/DMF at 0–25°C for 2–12 h to form esters; add HOBt/HOAt as needed. Minimizes dehydration side-reactions.
• Acid chloride route: SOCl2 (1.2–2.0 equiv) with catalytic DMF at 0–25°C gives lactyl chloride; subsequent acylation at −20 to 0°C to preserve configuration.
• Oxidation to pyruvate: TEMPO (5–10 mol%) with NaOCl/NaClO2 in biphasic CH2Cl2/H2O at 0–10°C; or Dess–Martin periodinane in DCM at 0–25°C. Control pH to prevent overoxidation.
• Lactide formation: heat neat or in high-boiling solvents (toluene/xylene) with catalysts (Sn(Oct)2, Zn, organic acids) at 120–180°C under reduced pressure to remove water.

Analytical/handling

• Use anhydrous conditions where water removal is key (esterification, activation). Verify isotopic integrity by ¹³C NMR (distinct C2 resonance, enhanced intensity) and HRMS (M+1 mass shift).
• Maintain L-configuration: avoid strong bases and high temperatures; consider Mitsunobu alternatives for inversion-controlled substitutions if needed.

Safety and Handling

Item-specific facts (from Product Data)

• Hazard Information (Signal Word, H-Statements, GHS Classification, Pictograms): Not specified for this item; refer to SDS.
• Research Use Note: For research use only.

General safety information for lactic acid (literature; consult the SDS for this catalog item)

• Likely hazards: causes skin and eye irritation; may cause respiratory irritation as aerosols/mists. Strongly acidic; can be corrosive to some materials at elevated concentrations.
• GHS (typical for lactic acid): Eye Irrit. 2A; Skin Irrit. 2 (literature). The exact classification for this item may differ; defer to the product SDS.
• Incompatibilities: strong oxidizers; strong bases (exothermic neutralization); reactive acid-sensitive materials (carbonates/metals evolving gas). Avoid mixing with hypochlorites (possible formation of chlorine under certain conditions).
• PPE: lab coat, safety glasses or splash goggles, and appropriate chemical-resistant gloves (e.g., nitrile). Use in a fume hood when heating or aerosol generation is possible.
• First aid (overview): skin—wash with water; eyes—rinse with water for ≥15 min and seek medical advice; inhalation—move to fresh air; ingestion—rinse mouth. Always follow institutional protocols and SDS.
• Handling tips: lactic acid is hygroscopic; keep containers tightly closed to maintain assay and isotopic enrichment. Avoid prolonged heating to prevent polymerization (lactide formation) or decomposition.
• Waste: collect acidic aqueous and organic residues in compatible, clearly labeled containers; neutralize/segregate per local regulations.

Solvent Selection

Applicability

• L-Lactic acid-2-¹³C is a small, polar, protic organic acid. Solvent choice influences reactivity, esterification rate, and analytical readouts.

General solvent behavior (literature)

• Polarity/miscibility: highly miscible with water; freely soluble in methanol, ethanol, isopropanol, acetone; limited solubility in nonpolar solvents (hexanes, toluene).
• Acid-base behavior: forms lactate salts in basic aqueous media (Na⁺/K⁺ lactate). In strongly hydrogen-bonding solvents, intramolecular H-bonding competes with solvation.
• Dielectric considerations: aqueous and alcohol solvents (high ε) favor ionization (carboxylate) and fast proton transfer; aprotic polar solvents (DMSO, DMF, MeCN) dissolve the neutral acid but suppress ionization unless base is added.

Selection tips

• For NMR tracer studies: use D2O or DMSO-d6 for ¹H/¹³C NMR; methanol-d4 or CD3CN for organic contexts. Add a drop of TFA-d or base sparingly if sharper carboxyl signals are needed.
• For esterification: use anhydrous alcohols (MeOH, EtOH, iPrOH) with catalytic acid (e.g., H2SO4, TsOH) or coupling agents in aprotic media (DCM, toluene) with drying agents.
• For biochemistry workflows: aqueous buffers (pH 3–5 for free acid; pH > 5 as lactate). Avoid strong oxidants.

Comparison (general)

• Water vs alcohols: water maximizes ionic forms (lactate) and is ideal for biochemical assays; alcohols enable direct ester formation.
• Aprotic polar (DMSO/DMF) help dissolve high loads without altering protonation, useful for stock solutions in synthesis/derivatization.

Storage and Reconstitution

Item-specific facts (from Product Data)

• Storage Conditions: Store at −20°C.
• Shipped In: Ice chest + Ice pads.

General guidance (literature/practice)

• Container: keep tightly sealed in chemically compatible, moisture-impermeable vials; lactic acid is hygroscopic and can absorb water, altering assay and promoting oligomerization.
• Light/temperature: store protected from light and heat. Minimize freeze–thaw cycles by preparing aliquots on first opening.
• Stability: isotopic label (¹³C) is not exchangeable and is inherently stable; chemical stability follows that of lactic acid—avoid prolonged heating or dehydrating conditions that favor lactide/oligomer formation. Specific shelf-life is not specified for this item; refer to CoA.

Reconstitution/solution prep (general)

• Solvents: water, aqueous buffers, or polar organics (MeOH, EtOH, DMSO). For NMR, D2O or DMSO-d6 are typical.
• pH control: for biochemical assays, adjust pH with NaOH/KOH to generate lactate; record final pH and ionic strength for reproducibility.
• Filtration: if particulate is present, filter through 0.2 μm PTFE/nylon as appropriate.

Labeling note

• Track lot numbers and isotopic enrichment in lab records to ensure traceability across experiments. For critical quantitation, verify concentration by acid–base titration or quantitative NMR (qNMR).

Structure and Identity

Item-specific facts (from Product Data)

• SKU: L465454
• Product Name: L-Lactic acid-2-¹³C
• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.

Literature/computed structural information (general reference for L-lactic acid-2-¹³C)

• Core scaffold: alpha-hydroxycarboxylic acid (lactic acid) with the chiral alpha-carbon (C2) isotopically enriched as ¹³C.
• Stereochemistry: L-lactic acid corresponds to the (S)-configuration at C2 (Cahn–Ingold–Prelog), unchanged by ¹³C labeling.
• Functional groups: one carboxylic acid (–CO2H) and one secondary alcohol (–CHOH) on the alpha-carbon; one terminal methyl (–CH3).
• Isotopic position: C2 (the chiral alpha-carbon bearing –OH) is ¹³C. This does not alter connectivity but shifts exact mass and isotopic patterns in MS and NMR.
• Representative labeled SMILES (literature): C13C@HC(=O)O (for the L/(S) enantiomer). Use only as a structural reference.

2D structure described in words (general)

• A three-carbon backbone: terminal methyl connected to a chiral center bearing a hydroxyl, which in turn is bonded to a terminal carboxyl group. The chiral center is the ¹³C-labeled atom in this isotopologue.

Synthetic Utility

Functional group leverage (general)

• Alpha-hydroxy acid: enables both nucleophilic (alcohol) and electrophilic (carboxyl) transformations. The adjacent functionality permits intramolecular reactions (e.g., lactide formation) and selective derivatizations.
• Chiral center (L configuration): can transfer asymmetry in certain transformations or serve as a chiral building block when converted to derivatives (esters, amides, oxazolines).

Typical transformations (literature)

• Esterification/transesterification: alcohols with acid catalysis (H2SO4, TsOH) or via coupling reagents (DCC/EDC) to give 2-¹³C-lactate esters.
• Activation of the acid: conversion to acid chloride (SOCl2, (COCl)2) or mixed anhydrides for acylation of nucleophiles; preserve stereochemistry by mild conditions and low temperatures.
• Oxidation/reduction: selective oxidation to 2-¹³C-pyruvic acid (TEMPO/BAIB, Dess–Martin); reduction to diols or to propionic derivatives under stronger conditions.
• Cyclization: dehydrative dimerization to 2-¹³C-lactide, allowing synthesis of position-labeled PLA for degradation and tracing studies.
• Protective group strategies: silylation or acylation of the hydroxyl to modulate reactivity independently from the carboxyl.

Isotope utility

• Embedding a 2-¹³C label provides a fixed spectroscopic handle to track the lactyl fragment through multi-step sequences by HRMS and ¹³C NMR.

Target Specificity

Not applicable to this product type.

• This item is a small-molecule isotopically labeled metabolite, not an antibody or affinity reagent. No antigen/epitope or species reactivity applies. Researchers seeking biological targeting information should refer to the Biological Roles and Reaction & Applications sections for use contexts.