L-R4W2 TFA - ≥98% , CAS No.206350-79-0(free base)

CAS: 206350-79-0(free base) Cat. No.: L288302 Peso molecular: 1014.2（free base）

CALIDAD & PUREZA ≥98%

Storage

Store at -20°C,Desiccated

Shipped In

Ice chest + Ice pads

Especificaciones

Especificaciones y pureza

≥98%

Mecanismos bioquímicos y fisiológicos

Vanilloid TRPV1 (VR1) receptor antagonist peptide (IC50~ 0.1μM); blocks Ca2+currents in dorsal root ganglion neurons. Analgesicin vivo.

Condiciones de almacenamiento de almacenamiento

Store at -20°C,Desiccated

Enviado en

Ice chest + Ice pads

Este producto requiere envío en cadena de frío. Los servicios terrestres y otros servicios económicos no están disponibles.

Tipo de acción

ANTAGONIST

Pureza

≥98%

Nombres e identificadores

Peso molecular

1014.2（free base）

Propiedades químicas y físicas

• Solubilidad: Soluble to 1 (mg/mL) in water

Application Protocols

No tested or validated application protocols are provided in the Product Data for this SKU. The following are general, non-item-specific starting points for peptide handling; optimize for your system.

• Stock solution preparation (general):
  • Bring vial to room temperature in a desiccator to prevent condensation. Add calculated volume of water or mildly acidic buffer to reach the desired concentration (e.g., 1–10 mM). Vortex, gently warm, and sonicate if necessary.
  • For poorly soluble cases, prepare a small-volume DMSO stock (e.g., 10–50 mM), then dilute into aqueous buffer with vigorous mixing; keep final DMSO ≤0.5–1% v/v for most biological assays.
• Quantitation:
  • Use UV at 280 nm leveraging tryptophan absorbance (if present) with appropriate extinction coefficient, or determine concentration gravimetrically and confirm by LC–MS.
• Filtration and storage:
  • Filter through 0.22 µm (low-protein-binding) if compatible. Aliquot and freeze at ≤−20 °C to minimize freeze–thaw cycles.

These are generic guidelines. For any critical or regulated workflow, develop and document method-specific SOPs and confirm with small-scale pilot tests.

Biological Roles

No item-specific biological roles are provided. The following is general context for peptides enriched in L-arginine and L-tryptophan (not specific to this SKU):

• Physicochemical drivers:
  • Arginine’s guanidinium group forms bidentate hydrogen bonds and strong electrostatic interactions with anionic biomolecules (phospholipids, nucleic acids, sulfated glycosaminoglycans).
  • Tryptophan’s indole ring engages in hydrophobic and cation–π interactions and can insert into membrane interfaces.
• Model systems:
  • Such peptides are frequently used to study membrane translocation, protein–peptide recognition, and phase separation phenomena of intrinsically disordered proteins where Arg/Trp content modulates condensate behavior (literature/general).
• Spectroscopic utility:
  • Intrinsic fluorescence of tryptophan (λex ~280 nm, λem ~350 nm; environment-sensitive) can report on conformational changes, binding, and microenvironment polarity (literature/general). Quenching by acrylamide or iodide is commonly used to probe accessibility.
• Enzymatic stability:
  • Short peptides may be susceptible to proteolysis by exo- and endopeptidases; N-/C-terminal capping or D-residue substitutions are often employed in research to enhance stability (general strategies).

These biological notes are provided for conceptual orientation only. Verify the exact sequence, termini, and modifications of L-R4W2 TFA for any mechanism-driven studies.

Buffer Applications

This product is a peptide reagent, not a buffering agent. Therefore, it is not typically used to set or maintain pH. However, buffer selection is crucial for preparing and using peptide solutions. General guidance:

• Recommended preparation media (general):
  • Ultrapure water or low-ionic-strength buffers; slightly acidic solutions (e.g., 5–20 mM acetate, citrate, or dilute HCl) can enhance solubility of basic peptides.
  • For neutral pH applications, dissolve first in water or mildly acidic solution, then adjust pH or dilute into the target buffer (e.g., PBS, HEPES). Avoid abrupt pH jumps that may cause precipitation.
• Additives and stability:
  • Include small amounts of salt (e.g., 50–150 mM NaCl) if needed to mitigate nonspecific adsorption to plastics and glass.
  • Avoid strong bases and prolonged pH > 9 to limit backbone and side-chain degradation.
• Filtration:
  • 0.22 µm filtration can improve solution clarity; pre-wet filters with buffer to reduce peptide loss via adsorption (general tip).

Item-specific buffer recipes, pKa, or buffering ranges do not apply to this peptide and are not provided.

Green Alternatives

As a peptide-based material, L-R4W2 TFA itself is not typically substituted by a “greener” chemical; however, greener practices can be implemented in its handling and analysis.

• Solvent choices (general guidance):

  • Prefer water or aqueous buffers as primary media whenever possible.
  • For chromatography, consider formic acid (0.1%) instead of TFA as a mobile phase modifier for LC–MS workflows to reduce ion suppression and persistent waste issues, acknowledging possible tradeoffs in peak shape/retention.
  • Minimize DMSO usage by optimizing aqueous solubilization (slight acidification, gentle warming, brief sonication).

• Process improvements:

  • Use micro-scale reactions/assays to reduce solvent and reagent consumption.
  • Choose energy-efficient lyophilization schedules and low-temperature storage that balance stability with power consumption (e.g., consolidated freezer space, monitored access).
  • Implement solvent recycling for preparative HPLC where feasible (e.g., reclaiming acetonitrile/water mixtures), ensuring purity requirements are still met.

• Comparative considerations (general):

  • TFA vs formic acid in LC: formic acid is more environmentally benign and MS-friendly; TFA affords superior chromatographic control in some separations. A split-flow or post-column addition approach can mitigate MS suppression while retaining TFA’s chromatographic benefits.

These suggestions are general/literature-based sustainability options and are not item-specific specifications.

Pharmaceutical Uses

No pharmacopeial status or excipient role is provided for this item. This product is labeled for research use only and is not intended for human or veterinary use.

General formulation context for research peptides (not item-specific, not clinical):

• Screening and pre-formulation studies may explore solubility, stability, and aggregation as a function of pH, ionic strength, and excipients (e.g., sugars, polysorbates) to inform basic developability assessments.
• The TFA counterion can influence hygroscopicity and solubility; research workflows sometimes exchange TFA for acetate, chloride, or phosphate to tailor behavior or reduce TFA-related assay interferences.
• Lyophilized peptide solids are commonly stored under inert gas at low temperature; reconstitution solvents are chosen based on intended in vitro assays (buffer compatibility, osmolarity, and pH stability).

No claims are made regarding therapeutic activity, clinical efficacy, or GMP suitability. For any regulated or translational use, separate GMP-grade material and full regulatory documentation would be required.

Physical Properties

Item-specific physicochemical specifications are not provided in the Product Data.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Melting point, boiling point, density, refractive index, UV cutoff: Not specified for this item; refer to CoA/Spec Sheet.

General/literature expectations for short arginine/tryptophan L-peptides (for context; not item specifications):

• Physical state: typically white to off-white amorphous solid or lyophilized powder (literature/general).
• Solubility profile: often high aqueous solubility at acidic to neutral pH due to protonated guanidinium groups; enhanced solubility in water, aqueous buffers, or dilute acids (e.g., 0.1% TFA, 0.1 M HCl). DMSO can be used for stock solutions when needed (literature/general).
• Ionization: arginine side chains pKa ≈ 12.5 (literature), rendering them cationic across physiological pH; indole of tryptophan is non-ionizable under most conditions (literature/general).
• UV absorbance: tryptophan exhibits strong absorbance near 280 nm (ε ≈ 5500 M−1 cm−1 per Trp; literature). Useful for concentration estimation by UV-Vis (general guidance).

Always verify exact solubility and concentration limits for this specific lot via CoA or preliminary small-scale trials.

Quality and Grades

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

Interpretation and guidance (general for research-grade peptides):

• Research grade typically indicates material suitable for laboratory research, screening, and method development. Purity is often assessed by HPLC and identity confirmed by MS; exact acceptance criteria and analytical traces (HPLC chromatogram, ESI/HRMS) should be reviewed on the CoA for this specific SKU.
• Counterion content: Product name includes “TFA,” indicating the peptide is provided as a trifluoroacetate salt. TFA residues can influence assay background (e.g., LC-MS ion suppression) or cell assays at high concentrations. If counterion content matters, consider desalting or counterion exchange (e.g., to acetate or HCl) before sensitive applications (general guidance).
• Residual solvents/water content, metal content, and bioburden/endotoxin: Not specified for this item; refer to CoA/Spec Sheet.
• Batch-to-batch consistency: For combinatorial libraries or screening sets, verify lot-specific purity, sequence confirmation, and net peptide content (NPC) prior to quantitative studies.
• Documentation: Request and retain the CoA/Spec Sheet for this SKU (L288302) to ensure the exact specifications, analytical methods, and acceptance criteria used by the manufacturer for release testing.

Reaction and Applications

Manufacturer-provided application notes are not listed for this item; the following contextual uses reflect general laboratory applications of short L-peptides enriched in arginine and tryptophan. Validate suitability for your workflow.

• Biochemical assays (general):
  • Substrate, ligand, or probe in protein–peptide interaction studies (e.g., binding to acidic or aromatic-rich protein patches via guanidinium and indole contacts).
  • Model systems for studying cation–π interactions, membrane association, and peptide self-assembly behavior.
• Analytical applications:
  • LC/LC–MS method development using tryptophan absorbance at 280 nm for quantitation; retention manipulation by gradient acetonitrile and ion-pairing modifiers.
• Materials and surface science:
  • Adsorption to anionic surfaces or polyanions (e.g., heparin mimetics) via multivalent arginine contacts; potential use in layer-by-layer assemblies (general literature context).
• Cell and molecular biology (general caution):
  • Arginine/tryptophan-rich peptides are widely explored as cell-penetrating motifs in research; conditions (concentration, exposure time, serum content) critically affect performance and cytotoxicity. This item is for research use only; perform appropriate controls and titrations.

Practical tips:

• Prepare fresh solutions; filter (0.22 µm) if compatible to remove particulates.
• Minimize exposure to strong bases and oxidants; indole side chains are light/oxidation sensitive.
• For adsorption/interaction studies, record ionic strength and pH rigorously, as guanidinium-mediated binding is salt- and pH-dependent.

Reaction Conditions

No synthetic reaction conditions are item-specific for this catalog peptide. The notes below provide general conditions relevant to handling and potential modification of short L-peptides (not specifications):

• Dissolution and handling:
  • Dissolve in water or mildly acidic aqueous media; gentle warming (room temperature to 37 °C) and brief sonication can aid solubilization. Avoid strong base and oxidants.
• LC method development (general):
  • Reverse-phase C18 columns; water/acetonitrile gradients with 0.05–0.1% formic acid (MS-friendly) or TFA (better peak shape). Column temps 30–40 °C; flow rates and gradients as appropriate for analytical/preparative scale.
• Conjugation (if applicable; confirm functional groups from CoA):
  • NHS-ester labeling: pH 7.5–8.5 in bicarbonate/HEPES buffer; minutes to hours at RT; quench with Tris or ethanolamine.
  • Click chemistry: CuAAC typically at RT in aqueous/tert-butanol with Cu(I) catalyst and ligand; strain-promoted variants in purely aqueous media.
• Stability testing (general):
  • Monitor by LC–MS at set intervals under stress (light, heat, pH extremes) to define handling limits. Indole oxidation can be tracked by mass shifts and new chromatographic peaks.

Expected yields, kinetics, and exact conditions are sequence- and modification-dependent and are not specified for this SKU.

Safety and Handling

Safety data specific to this item are not provided in the Product Data. Always consult the product SDS for authoritative information.

• GHS classification, signal word, hazard statements, pictograms: Not specified for this item; refer to SDS.
• General hazards (peptide/TFA salts; literature/general):
  • Low volatility solids; dust may cause mechanical irritation to eyes/respiratory tract.
  • Trifluoroacetate counterions are acidic; solutions can be mildly acidic and may irritate skin/eyes.
• Recommended PPE: lab coat, suitable gloves (e.g., nitrile), safety glasses/goggles. Handle powders in a fume hood or ventilated enclosure to minimize dust exposure (general good practice).
• Storage incompatibilities: avoid strong oxidizers and strong bases that may induce side reactions or degrade peptide; avoid prolonged exposure to moisture (hydrolysis risk) and light for indole-containing residues (literature/general).
• First-aid overview (general):
  • Skin/eye contact: rinse with water for at least 15 minutes; remove contaminated clothing; seek medical attention if irritation persists.
  • Inhalation: move to fresh air; seek medical attention if symptoms develop.
  • Ingestion: rinse mouth; seek medical advice.
• Spill/cleanup: minimize dust, gently collect solids, wipe with damp disposable tissues; dispose per institutional and local regulations.
• Fire: use CO2, dry chemical, or foam; combustion may release nitrogen oxides and HF-containing species due to TFA (literature/general).

Solvent Selection

Choosing a solvent for L-R4W2 TFA should balance peptide stability, solubility, and downstream compatibility. Item-specific solubility is not provided; the following are general best practices for arginine/tryptophan-rich peptides.

• Aqueous systems:
  • Start with ultrapure water or low-ionic-strength buffers. Acidify slightly (e.g., 0.1% TFA or 1–10 mM HCl) if needed to protonate basic sites and enhance solubility (general guidance).
  • For neutral pH work, PBS or HEPES buffers can be used after initial dissolution; avoid high pH (>9) to limit base-catalyzed hydrolysis.
• Organic cosolvents:
  • DMSO is a common cosolvent for stock solutions when water alone is insufficient. Dilute DMSO stocks into buffer with vigorous mixing to prevent precipitation (general practice).
  • Acetonitrile/water mixtures (with 0.05–0.1% TFA or formic acid) are often used for LC and analytical handling.
• Polarity and interactions (general):
  • Arginine guanidinium groups favor hydrogen bonding and ionic interactions with water; tryptophan indoles contribute hydrophobic and π–π interactions, which can drive aggregation at high concentrations. Gentle heating (≤37 °C) and sonication can help dissolution.

Comparison (general, not item-specific):

• Water (acidified) vs DMSO stocks: water is most biocompatible; DMSO provides higher maximum concentrations but may affect bioassays above 0.5–1% v/v.
• Formic acid vs TFA as mobile phase additives: formic acid is more MS-friendly; TFA can suppress MS signals but improves chromatographic peak shape.

Storage and Reconstitution

Item-specific storage and shipping details (from Product Data):

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

General best practices for peptide solids and solutions (literature/general guidance):

• Solid form:
  • Keep tightly capped under dry inert atmosphere if possible (desiccant present). Allow vial to equilibrate to room temperature in a desiccator before opening to prevent moisture condensation.
• Reconstitution:
  • Use sterile, oxygen-poor water or buffer when practical. Mild acidification (e.g., 1–10 mM HCl or 0.1% TFA) can improve solubility of basic peptides. Record pH after dissolution.
  • Prepare concentrated stocks, then dilute to working concentrations immediately before use. Avoid extended exposure to light and elevated temperature, especially for tryptophan-containing sequences.
• Storage of solutions:
  • Aliquot to single-use vials; store at −20 °C or below. Minimize freeze–thaw cycles; thaw on ice. Typical working solutions are stable for hours to a few days at 2–8 °C depending on sequence and buffer; confirm by LC–MS/HPLC.
• Stability and specifications:
  • Appearance, purity, water content, and counterion stoichiometry are Not specified for this item; refer to CoA/Spec Sheet.

For research use only.

Structure and Identity

Brief overview: L-R4W2 TFA is a peptide-derived research reagent. The product name implies an all-L stereochemistry with a composition enriched in arginine (R) and tryptophan (W), supplied as a trifluoroacetate (TFA) salt. Exact sequence, termini, and counterion stoichiometry are not provided in the Product Data.

• Chemical identity (item-specific):

  • CAS: 206350-79-0 (free base) [as provided]
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

• Structural features (general interpretation based on nomenclature; confirm against CoA):

  • Likely an L-peptide containing multiple guanidinium-bearing arginine residues (cationic side chains) and indole-containing tryptophan residues (aromatic, hydrophobic/π-stacking capable).
  • Provided as a TFA salt, implying protonated basic sites with trifluoroacetate counterions.
  • 2D description (general): a short peptide backbone (repeating –NH–CHR–CO–) with side chains: arginine (–(CH2)3–NHC(=NH)NH2) and tryptophan (indole-CH2–) appended to the α-carbon; all centers L-configured at Cα if per name. N-/C-termini (free, acetylated, amidated) are not specified.

• Stereochemistry: “L-” indicates L-configuration at peptide α-carbons (literature convention); exact details for this item are Not specified; see CoA.

Synthetic Utility

As an isolated peptide research reagent, L-R4W2 TFA is primarily an end product rather than a synthetic intermediate. However, it can serve as a functional component or comparator in method development and peptide chemistry studies.

• Utility in analytical method development (general):
  • Use as a standard to optimize reverse-phase HPLC/UPLC gradients for cationic, aromatic peptide separations.
  • Evaluate ionization efficiency and adduct patterns in ESI–MS for Arg/Trp-rich sequences (e.g., charge state distribution due to multiple basic sites).
• Conjugation and labeling (general strategies):
  • If N-terminus or lysine residues are available (sequence/termini not specified here), NHS ester labeling, click chemistry (azide/alkyne handles when present), or maleimide–thiol coupling (if cysteine is present) can be applied. Confirm functional handles from the CoA.
• Supramolecular assembly:
  • Arginine/tryptophan combinations are studied for coacervation with polyanions (e.g., nucleic acids), enabling materials and delivery research models.

Because the exact sequence, termini, and modifications for this SKU are not specified in the Product Data, verify reactive handles and compatibility before undertaking any derivatization or coupling experiments.

Target Specificity

No antigen, receptor, enzyme, or other biological target is specified for this product. It is supplied as a general research reagent.

• Item-specific target, epitope, clone, isotype: Not applicable/not specified for this item; refer to CoA/Spec Sheet if any application-specific validation is provided.

If used in binding or uptake studies, any observed specificity will be context- and assay-dependent and should be experimentally determined for the system of interest.

Preguntas frecuentes

What is the purity of this product?

This product is supplied at ≥98% purity (chemical assay). Lot-specific values are stated on the Certificate of Analysis.

How should this product be stored?

Store at ?20 °C, desiccated. Keep the container tightly closed with desiccant — the material is moisture-sensitive.

How is this product shipped?

This product ships in an insulated container with ice pads. Unpack on arrival and transfer it to the storage condition stated above.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.

What are the CAS number, molecular formula and molecular weight?

The CAS Number is 206350-79-0(free base), and the molecular weight is 1014.2（free base） g/mol.