L-Methionine(H-Met-OH) - Moligand™, ≥99% , CAS No.63-68-3

CAS: 63-68-3 Cat. No.: M101130 분자식: C₅H₁₁NO₂S 분자량: 149.21 Beilstein Registry Number: 1722294 EC 번호: 200-562-9

GRADE & PURITY Moligand™, ≥99%

Synonyms

H-Met-OH | (35S)Methionine | carbon-11 methionine | L-2-Amino-4methylthiobutyric acid | METHIONINE [II] | L-Methionin | L-Methionine-34S | L-Methioninum | 1pg2 | Methionine [USAN:USP:INN:BAN] | MFCD00063097 | (2S)-2-amino-4-(methylsulfanyl)butanoic acid |

Storage

Store at 2-8°C,Protected from light,Argon charged

Shipped In

Wet ice

개요

L-Methionine is an essential amino acid for human development, hepatoprotectant, acetominophen poisoning antidote, and urinary acidifier.
An essential amino acid

Application:

L-Methionine is used as an essential amino acid for human development and therapeutically acts as an antidote for acetaminophen poisoning. It serves as a chelating agent for heavy metals, as a flavoring agent and nutritional supplement for foods. It acts as a feed additive, vegetable oil enrichment and as a single cell protein. In addition to this, it is used as a hepatoprotectant and also acts as a lipotropic agent and prevents excess fat buildup in the liver.

Specifications

동의어

H-Met-OH | (35S)Methionine | carbon-11 methionine | L-2-Amino-4methylthiobutyric acid | METHIONINE [II] | L-Methionin | L-Methionine-34S | L-Methioninum | 1pg2 | Methionine [USAN:USP:INN:BAN] | MFCD00063097 | (2S)-2-amino-4-(methylsulfanyl)butanoic acid |

사양 및 순도

Moligand™, ≥99%

생화학 및 생리적 메커니즘

Methionine is an essential amino acid which acts a precursor for transmethylation and transsulphuration. In proteins, L-methionine is the biologically active form.The adenosylation of methionine results in the formation of S-adenosyl-L-methionine (SAM), w

보관 조건

Store at 2-8°C,Protected from light,Argon charged

배송

Wet ice

이 제품은 콜드 체인 배송이 필요합니다.지상 및 기타 경제 서비스는 사용할 수 없습니다.

등급

Moligand™

순수함

≥99%

이름과 식별자

Pubchem Sid

488180013

Pubchem Sid Url

https://pubchem.ncbi.nlm.nih.gov/substance/488180013

정식 스마일

CSCC[C@H](N)C(O)=O

IUPAC Name

(2S)-2-amino-4-methylsulfanylbutanoic acid

InChIKey

FFEARJCKVFRZRR-BYPYZUCNSA-N

INCHI

1S/C5H11NO2S/c1-9-3-2-4(6)5(7)8/h4H,2-3,6H2,1H3,(H,7,8)/t4-/m0/s1

이성체 SMILES

CSCC[C@@H](C(=O)O)N

WGK 독일

1

RTECS

PD0457000

분자량

149.21

Beilstein

1722294

Reaxy-Rn

1722294

Reaxys-RN_link_address

https://www.reaxys.com/reaxys/secured/hopinto.do?context=S&query=IDE.XRN=1722294&ln=

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organic acids and derivatives
    • 분류 Carboxylic acids and derivatives
      • Subclass Amino acids, peptides, and analogues
        • Level5 Amino acids and derivatives
          • Level6 Alpha amino acids and derivatives
            • Level7 Methionine and derivatives

• Kingdom: Organic compounds
• Superclass: Organic acids and derivatives
• 분류: Carboxylic acids and derivatives
• Subclass: Amino acids, peptides, and analogues
• Intermediate Tree Nodes: Amino acids and derivatives - Alpha amino acids and derivatives
• Direct Parent: Methionine and derivatives
• Alternative Parents: L-alpha-amino acids Thia fatty acids Amino acids Sulfenyl compounds Monocarboxylic acids and derivatives Dialkylthioethers Carboxylic acids Organopnictogen compounds Organic oxides Monoalkylamines Hydrocarbon derivatives Carbonyl compounds
• Molecular Framework: Aliphatic acyclic compounds
• Substituents: Methionine or derivatives - Alpha-amino acid - L-alpha-amino acid - Thia fatty acid - Fatty acid - Fatty acyl - Amino acid - Carboxylic acid - Monocarboxylic acid or derivatives - Thioether - Sulfenyl compound - Dialkylthioether - Amine - Organic oxygen compound - Primary amine - Organosulfur compound - Organooxygen compound - Organonitrogen compound - Organic nitrogen compound - Primary aliphatic amine - Carbonyl group - Organopnictogen compound - Organic oxide - Hydrocarbon derivative - Aliphatic acyclic compound
• 설명: This compound belongs to the class of organic compounds known as methionine and derivatives. These are compounds containing methionine or a derivative thereof resulting from reaction of methionine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom.
• External Descriptors: Common amino acids

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

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SLC6A3 Tclin Dopamine transporter (10535 Activities)

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PDE3A Tclin Phosphodiesterase 3A (3309 Activities)

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HTR2B Tclin Serotonin 2b (5-HT2b) receptor (10323 Activities)

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TBXA2R Tclin Thromboxane A2 receptor (5717 Activities)

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PDE4A Tclin Phosphodiesterase 4A (1943 Activities)

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Homo sapiens (32628 Activities)

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SLC7A5 Tchem L-type amino acid transporter 1 (388 Activities)

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관련 대상(비인간)

Mat1a S-adenosylmethionine synthetase alpha and beta forms (31 Activities)

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Mat2a S-adenosylmethionine synthetase gamma form (83 Activities)

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Hdac6 Histone deacetylase 6 (222 Activities)

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Pkm Pyruvate kinase isozymes M1/M2 (66 Activities)

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rep Replicase polyprotein 1ab (378 Activities)

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Slc16a10 Monocarboxylate transporter 10 (73 Activities)

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Mat1a S-adenosylmethionine synthetase (MAT 1 and MAT 2) (155 Activities)

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Slc1a5 Amino acid transporter (271 Activities)

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작용 메커니즘

화학 및 물리적 특성

• 용해성: Soluble in 1M HCl (50 mg/ml), and water (56.6 mg/ml at 25 °C). Insoluble in ethanol, acetone, and ether.
• 감도: Light & Air sensitive.
• 특정 회전[α]: 24° (C=8,HCl (1+1))
• 녹는점(°C): 280-282°C
• 분자량: 149.210 g/mol
• XLogP3: -1.900
• Hydrogen Bond Donor Count: 2
• Hydrogen Bond Acceptor Count: 4
• Rotatable Bond Count: 4
• Exact Mass: 149.051 Da
• Monoisotopic Mass: 149.051 Da
• Topological Polar Surface Area: 88.600 Ų
• Heavy Atom Count: 9
• Formal Charge: 0
• Complexity: 97.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 1
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

No vendor-validated biological assay protocols are specified for this item. The following general, literature-based research procedures are common starting points; adjust to your system and consult primary sources.

• Preparation of stock solutions (research):
  • Dissolve L-Methionine in ultrapure water to 100–500 mM. Adjust pH to 7.0–7.4 if needed. Filter sterilize (0.22 μm) for cell-based work. Store aliquots at 2–8 °C protected from light; use within several days.
• Use as antioxidant excipient (research):
  • Add 1–10 mM L-Met to protein formulations buffered at pH 6.5–7.5 to reduce oxidative modifications during storage. Validate impact by LC-MS peptide mapping and methionine sulfoxide assays.
• Amino acid analysis standard (research):
  • Prepare calibration series (e.g., 1–500 μM) in mobile phase-compatible solvent. Derivatize if using pre-column methods (OPA/FMOC) and quantify by HPLC/FLD or LC-MS.
• Solution-phase coupling (research):
  • Combine L-Met (1.0 eq), partner acid/amine (1.0–1.2 eq), EDC·HCl (1.2 eq), NHS (1.2 eq) in water/MeCN at pH 7.5–8.0; stir 1–4 h at 20–25 °C. Quench and purify by RP-HPLC.

These are non-binding starting points intended for experienced researchers. Always run small-scale pilots and appropriate controls.

Biological Roles

The following summarizes literature knowledge of L-Methionine’s roles in biology; these are general properties of the molecule and not specific to any medical use.

• Essential amino acid: L-Methionine is an essential sulfur-containing amino acid incorporated into proteins via AUG initiation codons in mRNA (literature).
• Methylation metabolism: Precursor to S-adenosyl-L-methionine (SAM), the universal methyl donor for DNA/RNA/protein/lipid methyltransferases. SAM is formed by methionine adenosyltransferase; subsequent demethylation leads to S-adenosylhomocysteine and homocysteine.
• Transsulfuration (literature): Methionine contributes sulfur for cysteine biosynthesis via homocysteine and cystathionine; links to glutathione synthesis and cellular redox homeostasis.
• Redox chemistry: The thioether can be reversibly oxidized to methionine sulfoxide in proteins; methionine sulfoxide reductases (MsrA/MsrB) repair oxidative damage, serving as a cellular antioxidant cycle.
• One-carbon cycle integration: Methionine is central to folate-mediated one-carbon metabolism, affecting methyl group balance in anabolic processes (nucleotides, phosphatidylcholine).
• Bioprocessing relevance (research context): Supplementation in media influences growth and recombinant protein expression; addition to protein formulations can mitigate oxidative degradation pathways by acting as a sacrificial scavenger for reactive oxygen species.

Note: These roles are provided for biochemical context only. SKU M101130 is for research use only and not for clinical or nutritional applications.

Buffer Applications

L-Methionine itself is not a conventional buffering agent, but its acid–base groups impart limited buffering capacity near its pKa values and it is frequently used as an auxiliary component in aqueous systems.

• Buffering characteristics (literature):
  • pKa1 ~2.2 (carboxyl) and pKa2 ~9.2 (amino); limited effective buffering near pH ~2–3 and ~8–10. Not recommended as a primary buffer.
• Practical laboratory uses:
  • Antioxidant additive: 1–10 mM L-methionine is commonly added to buffers and protein formulations as a sacrificial scavenger for oxidants, reducing methionine oxidation in target proteins (research use).
  • Electrophoresis/cell-free systems: Inclusion can modulate redox environment and provide substrate for translation initiation in in vitro expression.
• Compatibility tips:
  • Maintain neutral pH for protein work (e.g., phosphate, HEPES, or Tris as the primary buffer) and add L-Met as a co-solute.
  • Prepare fresh solutions, protect from light, and sparge with inert gas where oxidation is a concern. Filter (0.22 μm) if sterility is required for cell-based assays.
• Example preparation (research guidance, literature):
  • 10 mM L-Met in 20 mM HEPES, 150 mM NaCl, pH 7.4; dissolve L-Met in water, adjust pH, then mix with buffer concentrate.

For strong, stable buffering, choose established buffers (e.g., phosphate pH 6–8, HEPES pH 6.8–8.2, Tris pH 7–9) and use L-Met only as an additive.

Green Alternatives

Green chemistry considerations with L-Methionine focus less on replacing the substrate and more on optimizing solvent systems and coupling reagents in peptide/bioconjugation workflows.

• Solvent choices (literature):
  • Prefer water or aqueous ethanol for dissolution and biochemistry; for peptide couplings, evaluate greener aprotic solvents such as N-butylpyrrolidone (NBP) or PolarClean as partial replacements for DMF/NMP when using protected derivatives of methionine.
  • In analytical prep, use volatile, mild buffers (ammonium acetate/formate) to reduce persistent waste versus phosphate.
• Reagent choices (literature):
  • Use water-compatible coupling systems (EDC/HOAt or EDC/sulfo-NHS) in aqueous or mixed media to reduce reliance on chlorinated solvents.
  • Minimize excess activating reagents; implement in situ activation to reduce by-products.
• Process design:
  • Conduct reactions at ambient temperature and near-neutral pH to reduce energy usage and side-product formation (e.g., sulfoxide).
  • Apply real-time monitoring (pH, UV/LC) to avoid over-oxidation.

Comparison (general):

• Conventional SPPS: DMF/NMP, HBTU/HATU; generates significant solvent waste and uses reproductive toxins.
• Greener adaptation: NBP/PC (PolarClean) co-solvents, lower E-factor; water-assisted couplings for short peptides or solution-phase steps.

Trade-offs:

• Greener solvents may slow coupling rates or affect resin swelling; empirical optimization is required.
• Aqueous systems limit solubility of hydrophobic partners; consider mixed aqueous–bio-based co-solvents.

Note: The substrate itself (L-Met) is a bio-derived feedstock and is generally benign; the main green impact lies in solvent/reagent selection.

Pharmaceutical Uses

This section summarizes literature/formulation roles; it does not imply suitability of SKU M101130 for any regulated use. Product is for research use only.

• Excipient/formulation roles (literature):
  • Antioxidant/excipient: L-Methionine is used as a sacrificial antioxidant in protein and peptide formulations to limit oxidation of susceptible residues (e.g., Met, Trp).
  • pH-modulating co-solute: Minor contribution to buffer capacity near its pKa values; typically used alongside conventional buffers.
  • Tonicity/osmotic contributor at modest concentrations.
• Manufacturing/processing:
  • Included in some lyophilization formulations to protect proteins from oxidative stress during freeze-drying and storage.
  • May be present in cell culture media and fermentation feeds as an essential nutrient for upstream bioprocessing (research and manufacturing contexts).
• Standards/monographs (literature context):
  • L-Methionine has pharmacopeial monographs (e.g., USP, Ph. Eur.). This does not assert or confer compliance for this specific item; consult the CoA/Spec Sheet if pharmacopeial attributes are required for your workflow.

No therapeutic or clinical claims are made; selection and qualification for any regulated application must be based on your internal specifications and regulatory assessment.

Physical Properties

Item-specific specifications are not listed in the product data; consult the CoA/Spec Sheet for definitive values. The following are literature/general properties for L-Methionine to aid method development:

• Physical state/appearance: Not specified for this item; refer to CoA/Spec Sheet. (Literature: crystalline solid)
• Molecular weight: 149.21 g/mol (literature)
• Acid–base properties (literature):
  • pKa1 (carboxyl): ~2.2
  • pKa2 (amino): ~9.2
  • Side chain thioether: non-ionizable under typical aqueous pH
  • Isoelectric point (pI): ~5.7–5.8
• Solubility (literature):
  • Water: readily soluble; solubility increases with temperature and at acidic or basic pH due to ionization.
  • Organic solvents: sparingly soluble in most nonpolar/weakly polar organics; enhanced solubility in alcohol–water mixtures or as protected derivatives (e.g., Fmoc/tBoc/tBu forms).
• Thermal behavior (literature):
  • Melting point: high; reported to decompose on heating > ~280 °C (dec.).
• Partition/refractive (literature/estimates):
  • LogP (octanol/water) for zwitterionic amino acids is typically negative; L-Met behaves as hydrophilic in water at neutral pH.
  • Optical rotation: L-form is dextrorotatory under standard conditions; magnitude depends on solvent, concentration, and temperature.

Note: Values above are provided as general literature guidance, not item specifications for SKU M101130.

Quality and Grades

• Item-specific grade: Moligand™ (per product data).
  • Interpretation: Moligand™ is Aladdin’s branded line oriented toward ligand/coordination and building-block applications in synthesis and chemical biology. It indicates the item is intended for research use, including as a precursor or component in ligand design or peptide/bioconjugation workflows. Exact impurity profile, assay, metal content, and stabilizers are Not specified for this item; refer to CoA/Spec Sheet.
• Research Use Only: This product is labeled for research use only; not for human or animal therapeutic or diagnostic use.
• What the grade implies in practice (general guidance):
  • Emphasis on consistent identity and suitability for method development in coordination/bioconjugation chemistry.
  • For peptide synthesis or coordination assays where trace metals and oxidation state matter, verify lot-specific parameters (e.g., residual metals, water, optical purity, enantiomeric excess) on the CoA.
• Appearance, assay, and optical rotation: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/antioxidants: None listed in product data. If your application is oxidation-sensitive, consider handling under inert gas and adding scavengers in your process, as appropriate.
• Compliance/monographs (literature context): L-Methionine has pharmacopeial monographs (e.g., USP/Ph. Eur., literature). This listing does not imply compliance of SKU M101130 with any pharmacopeia; verify via CoA if relevant to your workflow.

Reaction and Applications

As a chiral, sulfur-containing α-amino acid, L-Methionine (H-Met-OH) is broadly useful in synthesis and biochemistry.

• Peptide/bioconjugation chemistry (literature):
  • Building block for peptide synthesis (solution- and solid-phase). The thioether side chain is nucleophilic but relatively unreactive toward many coupling conditions, minimizing side reactions compared to cysteine.
  • In SPPS, protected forms (e.g., Fmoc-L-Met-OH) are commonly used; the free acid can serve in solution-phase coupling after in situ activation.
• Chiral pool/auxiliary uses (literature):
  • Source of chirality for asymmetric synthesis; conversion to derivatives (e.g., sulfonium salts, oxazolines) can transfer stereochemical information.
• Redox chemistry (literature):
  • The thioether is selectively oxidized to methionine sulfoxide and sulfone, enabling chemoselective oxidations and serving as a probe of oxidative conditions.
• Coordination/ligand contexts (general):
  • Thioether sulfur can act as a soft donor to metals in model complexes; methionine residues are key binding motifs in metalloproteins. Free L-Met can be used in screening/competition assays to probe S-donor interactions.
• Analytical/biochemical applications (literature):
  • Substrate/standard in amino acid analysis, metabolomics, and isotope-dilution studies (with labeled analogs).
  • Additive in protein formulations or cell-free systems as an antioxidant scavenger to mitigate oxidation (research use).

Practical tips:

• Drying/atmosphere: Product is supplied argon charged; maintain inert atmosphere to minimize oxidation during coupling or storage in solution.
• Coupling: Use water-compatible carbodiimides (e.g., EDC) or uronium salts (e.g., HATU) with buffering near pH 7–8 in aqueous media; avoid strong oxidants and nitrosating conditions.

Reaction Conditions

General, literature-based conditions when working with L-Methionine (free acid) are summarized below. Optimize for your specific system.

• Peptide/amide coupling (solution phase):
  • Solvent: Water or water/miscible organic (e.g., MeCN, DMF) buffered pH 7–8.
  • Activators: EDC·HCl with NHS/sulfo-NHS or HATU/HBTU in mixed media.
  • Base: Mild tertiary bases (DIPEA) in organic media; adjust pH carefully in aqueous systems.
  • Temperature/time: 20–25 °C, 0.5–12 h depending on partners; monitor by LC/MS.
• SPPS (with protected derivatives; literature):
  • Solvent: DMF or greener alternatives (NBP/PolarClean blends) for Fmoc protocols.
  • Deprotection: 20% piperidine in DMF; include scavengers during final TFA cleavage to protect Met from oxidation/alkylation (e.g., thioanisole, EDT). Avoid strong oxidants.
• Selective oxidation of Met side chain (literature):
  • Oxidant: H2O2 (0.5–3 eq) or m-CPBA in MeOH/H2O at 0–25 °C affords sulfoxide; excess/stronger conditions give sulfone.
  • Control: Inert atmosphere and low temperature minimize overoxidation.
• Metal coordination tests (research):
  • Aqueous buffer pH 6–7.4; add metal salt incrementally while monitoring by UV/Vis or NMR; avoid competing strong ligands if probing S-donor interactions.
• Stability considerations:
  • Avoid nitrosating conditions and halogenating agents.
  • Light and oxygen promote slow oxidation; store under inert gas as provided.

Note: Yields, rates, and selectivity are system-dependent; consult the primary literature for your exact transformation and scale.

Safety and Handling

Hazard classifications and GHS details are not specified for this item; refer to the product SDS for authoritative safety information.

• GHS/Classification: Not specified for this item; refer to CoA/Spec Sheet and SDS.
• Expected hazards (general for amino acids, literature): Typically low acute toxicity; may cause mechanical irritation to eyes/respiratory tract as dust. Avoid inhalation and contact.
• Special chemical risks:
  • Susceptible to oxidation of the thioether to methionine sulfoxide/sulfone under strong oxidants, light, or prolonged air exposure; this item is supplied argon charged and should be protected from light (per product data).
• Recommended PPE/practices (good laboratory practice):
  • Wear lab coat, nitrile gloves, and safety glasses.
  • Handle powders in a fume hood or with local exhaust to minimize dust.
  • Avoid strong oxidizing agents and halogens; separate from nitrosating agents and strong acids/bases when not in controlled procedures.
• First-aid overview (general):
  • Inhalation: Move to fresh air; seek medical advice if symptoms persist.
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing; seek attention if irritation continues.
  • Ingestion (laboratory context): Rinse mouth; seek medical advice.
• Fire safety: Not easily combustible as an amino acid solid; if involved in a fire, use water spray, CO2, dry chemical, or foam. Decomposition may produce sulfur oxides and nitrogen oxides.
• Spill response: Avoid dust formation; collect mechanically; wash residue with water.

Always consult the SDS supplied with the lot for definitive hazard, exposure limits, and disposal guidance.

Solvent Selection

L-Methionine is a zwitterionic, hydrophilic amino acid; solvent choice is dominated by its acid–base behavior and the non-ionizable thioether side chain.

• Polarity/miscibility (literature):
  • Highly polar and readily soluble in water; solubility increases under acidic (–NH3+) or basic (–COO–) conditions.
  • Sparingly soluble in most anhydrous, nonpolar organic solvents; practical dissolution often relies on aqueous or mixed aqueous-organic systems.
• Practical solvent systems by use case:
  • Aqueous buffers (pH 2–9): Best for biochemical work, antioxidant supplementation, or as a peptide component in solution-phase manipulations.
  • Mixed media: Water/methanol or water/ethanol for analytical sample prep; maintain pH near neutrality to limit side reactions.
  • Anhydrous organic media: Use protected derivatives (e.g., Fmoc/tBoc/tBu forms) for peptide coupling in DMF, NMP, DCM; the free amino acid has limited solubility in these.
• Dielectric considerations (literature): Water (ε ~78) supports full ionization and dissolution; in lower-ε solvents, ion pairing and precipitation are common without co-solvents or salts.
• When to choose L-Met vs alternatives:
  • Select the free acid (H-Met-OH) for aqueous biochemical studies, redox scavenging tests, or as a calibrant/standard.
  • Use protected methionine derivatives for solid-phase peptide synthesis (SPPS) in aprotic solvents to ensure solubility and reactivity.
• Compatibility notes:
  • Avoid strong oxidants in solvent systems; include inert atmosphere for long dissolutions to minimize sulfoxide formation.
  • For LC methods, volatile buffers (ammonium formate/acetate) aid MS-compatibility when analyzing methionine.

Storage and Reconstitution

• Storage conditions (product data):
  • Store at 2–8 °C.
  • Protect from light.
  • Argon charged.
  • Shipped on wet ice.
• Rationale and handling notes:
  • The thioether side chain can oxidize on exposure to air and light; the inert gas blanket and light protection help maintain the reduced state.
  • Minimize headspace and repeated container openings; if possible, backfill with argon or nitrogen after use.
• Reconstitution (general research guidance):
  • Solvent: Ultrapure water or appropriate buffer. Target pH 6.5–7.5 for most biochemical applications.
  • Concentration: Common stocks 100–500 mM; warm gently and stir to dissolve. Avoid strong oxidants and metal contaminants in diluents.
  • Filtration: If sterility is required, pass through a 0.22 μm membrane. Use low-protein-binding filters for formulation work.
• In-use stability:
  • Aqueous solutions are prone to slow oxidation; prepare fresh as needed. Store working solutions at 2–8 °C, protected from light, preferably under inert headspace, and use within a few days.
• Appearance and specific limits: Not specified for this item; refer to CoA/Spec Sheet.

Always follow good laboratory practice and consult the CoA/SDS for lot-specific guidance.

Structure and Identity

L-Methionine (H-Met-OH) is the proteinogenic, sulfur-containing L-α-amino acid used as a building block in peptides and as a biochemical substrate.

• Item identifiers (product data):
  • SKU: M101130
  • Product Name: L-Methionine (H-Met-OH)
  • CAS: 63-68-3
  • CID: 6137
  • InChIKey (as provided): 81193
• Core chemical identity (literature):
  • Synonyms: L-2-amino-4-(methylthio)butyric acid; L-Met
  • Molecular formula: C5H11NO2S (literature)
  • Molecular weight: 149.21 g/mol (literature)
  • SMILES (L-configuration): CSCCC@HC(=O)O (literature)
  • InChIKey: FFVZCMFYQHEVQH-UHFFFAOYSA-N (literature)
• Structural features (general description):
  • Functional groups: α-amino (–NH2/–NH3+ depending on pH), α-carboxyl (–COOH/–COO–), and a neutral thioether side chain (–S–CH3).
  • Stereochemistry: Single stereocenter at the α-carbon in the L-configuration (S absolute configuration by CIP for the natural isomer).
  • 2D structure (verbal): A four-carbon backbone bearing at Cα both an amino and a carboxylate, with the side chain –CH2–CH2–S–CH3 terminating in a methyl thioether. In aqueous media near neutral pH, the structure is a zwitterion (+NH3 and –COO–).

Synthetic Utility

L-Methionine (H-Met-OH) offers a versatile combination of functional handles: a nucleophilic amine, a carboxylic acid, and a thioether side chain, plus a defined L-stereocenter.

• Functional group interconversions (literature):
  • Amide/peptide bond formation via carbodiimide or uronium activation; selective N-acylation when carboxyl is protected.
  • Esterification of the carboxyl group for prodrugs/intermediates; formation of activated esters (NHS, pentafluorophenyl) for conjugation.
  • Thioether oxidation to sulfoxide (diastereomeric at sulfur) or sulfone, enabling access to polarity-tuned derivatives.
• Chiral pool applications:
  • Use of the α-stereocenter to induce asymmetry in subsequent transformations; conversion to chiral auxiliaries (e.g., via sulfonium/oxazoline intermediates) reported in literature.
• Bioconjugation selectivity:
  • Methionine’s thioether is less reactive than cysteine thiols, allowing selective modifications elsewhere; conversely, chemoselective Met-targeting reagents (e.g., hypervalent iodine, oxaziridines) can label Met residues.
• Protecting group strategy (literature):
  • For SPPS: Fmoc-L-Met-OH with side chain left unprotected; avoid strong oxidants and electrophiles that can S-alkylate.
  • In solution: tBoc or Cbz on the amine; methyl/benzyl esters on the carboxyl as needed.
• Coordination models:
  • As an S-donor, methionine can serve in simple model complexes to probe soft metal interactions (e.g., Pt(II), Cu(I)), useful in mechanistic studies.

These utilities make L-Met a robust entry point for peptide chemistry, redox probes, and chiral synthesis under mild, aqueous-compatible conditions.

Target Specificity

Not applicable. This product is a small-molecule amino acid, not an antibody or affinity reagent. No antigen/epitope or species reactivity applies. For biochemical selectivity toward enzymes or receptors, refer to the Biological Roles and Reaction & Applications sections for general context.