m-PEG25-Propargyl , CAS No.M1445672

CAS: M1445672 Cat. No.: M1445672 분자식: C₅₂H₁₀₂O₂₅ 분자량: 1127.35

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

개요

m-PEG25-Propargyl is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs. m-PEG25-Propargyl is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.

Specifications

보관 조건

Store at -20°C

배송

Ice chest + Ice pads

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이름과 식별자

분자량

1127.35

Application Protocols

Below is an example research protocol for CuAAC coupling of m-PEG25-Propargyl to an azide-bearing partner. This is general literature guidance and not a product specification; optimize for your system.

• Materials

  • Azide-functional substrate (limiting reagent)
  • m-PEG25-Propargyl (1.2–2.0 equiv vs azide sites)
  • CuSO4·5H2O (1–5 mol% vs azide)
  • Sodium ascorbate (5–20 mol% vs azide)
  • Ligand (e.g., THPTA or BTTAA, 1–2 equiv vs Cu)
  • Solvent: H2O/t-BuOH (1:1) or H2O/DMSO; pH 7.2 phosphate buffer if biocompatibility required

• Procedure

  1. Dissolve the azide substrate in buffer/solvent to 0.5–2 mM in azide groups.
  2. Dissolve m-PEG25-Propargyl in the same solvent; add 1.2–2.0 equiv relative to azide.
  3. Add ligand, then CuSO4 stock; start reaction by adding sodium ascorbate last. Final Cu: 0.1–1 mM typical.
  4. Stir at 20–25°C for 1–4 h (or until azide IR band ~2100 cm−1 disappears). Protect from air if sensitive.
  5. Quench by adding EDTA after completion if desired; remove copper by dialysis/gel filtration.
  6. Purify the conjugate by dialysis (MWCO chosen relative to product), ultrafiltration, or precipitation.

• QC suggestions

  • IR (loss of azide peak), 1H NMR (triazole proton ~7–8 ppm), SEC/GPC (Mn shift), UV/Vis if chromophores present.

For moisture-sensitive couplings, dry all reagents and use anhydrous DMF/DMSO under inert atmosphere.

Biological Roles

This product is a synthetic PEG reagent intended for research use only. It does not have inherent biological activity but imparts physicochemical properties when conjugated.

• PEG-related roles (literature/general)

  • Hydration and stealth: PEG chains create a highly hydrated shell that reduces protein adsorption and nonspecific interactions on surfaces and macromolecules.
  • Solubility enhancement: Conjugation to PEG can improve aqueous solubility and colloidal stability of hydrophobic entities.
  • Spacing and flexibility: The flexible PEG25 spacer separates functional cargos from surfaces or biomolecules, mitigating steric hindrance and improving binding accessibility in assays.

• Conjugation handle

  • The propargyl terminus enables selective coupling to azides via CuAAC, creating a stable triazole linkage that is resistant to hydrolysis and many enzymatic pathways.

• Biochemical compatibility

  • PEGs are widely used in biochemical assays and surface passivation due to low nonspecific binding. For sensitive biological systems, ensure removal of copper and unreacted small-molecule reagents after conjugation.

No therapeutic or clinical claims are made or implied. Suitability for specific biological systems should be validated empirically.

Buffer Applications

While m-PEG25-Propargyl is primarily a conjugation reagent rather than a pH buffer, PEG chains can influence buffer behavior and are commonly used as additives in biochemical workflows.

• Additive roles (literature/general)

  • Crowding agent: PEG increases effective macromolecular concentrations, influencing folding/assembly and phase behavior.
  • Precipitant: PEG is used for protein/DNA precipitation and crystallization screening; monofunctional mPEG can exhibit similar osmotic effects.
  • Stabilizer: PEG can reduce nonspecific adsorption to plastics and surfaces.

• Practical guidance

  • Typical working concentrations range from 0.1% to 20% w/v depending on application; optimize for each system.
  • For conjugation workflows, choose buffers that are compatible with CuAAC (e.g., phosphate, HEPES, or Tris; avoid azide-containing buffers which compete in reactions, and avoid strong copper chelators like EDTA during coupling).
  • After coupling, copper can be removed by dialysis, gel filtration, or chelating resins; then buffers with chelators may be reintroduced as needed.

Note: This section provides general usage context. This product is not a buffering agent and has no defined buffering capacity.

Green Alternatives

m-PEG25-Propargyl is already compatible with many aqueous and low-toxicity solvent systems, enabling greener workflows. Optimization can further reduce environmental footprint.

• Greener choices (literature/general)

  • Solvent selection: Prefer water or water/ethanol mixtures for CuAAC when substrates permit; avoid high-boiling polar aprotics if not necessary.
  • Copper management: Use efficient water-soluble ligands (e.g., BTTAA, THPTA) to minimize copper loading and facilitate removal; consider copper scavengers and chelating resins for waste reduction.
  • Energy: Reactions often proceed at ambient temperature; avoid unnecessary heating.

• Comparison (general guidance)

  • Aqueous CuAAC vs organic CuAAC
    • Pros (aqueous): Lower solvent hazard, improved biocompatibility, easy cleanup.
    • Cons: Some hydrophobic substrates require co-solvents or surfactants.
  • Ethanol/water vs DMSO/DMF
    • Pros: Lower toxicity, easier solvent recovery.
    • Cons: Limited solubility window; may slow rates without proper ligands.

• Alternative chemistries

  • If copper is undesirable, consider azide–DBCO (SPAAC) strategies. Note: This item is a terminal alkyne, not strained; a strained alkyne on the counterpart is required.

Adopt lifecycle-conscious practices: minimize copper and organic solvent usage, and implement appropriate aqueous waste treatment.

Pharmaceutical Uses

For research use only. The following describes general formulation roles of PEG-based reagents without implying clinical use of this specific item.

• Excipient and materials roles (literature/general)

  • Solubilization and stabilization: PEGylation can improve solubility and reduce aggregation of research-grade biomolecules and nanoparticles.
  • Surface passivation: PEG coatings on research devices/particles reduce nonspecific adsorption in analytical workflows.
  • Spacer/linker: mPEG25 provides a hydrophilic, flexible spacer with a single conjugation site, useful for assembling research-grade conjugates and prototypes.

• Considerations for development workflows

  • Control of Mn and dispersity improves consistency of conjugate properties.
  • Residual copper from CuAAC must be minimized for sensitive biological assays; employ ligands, low copper loadings, and post-reaction purification.
  • Analytical characterization: 1H NMR for end-group verification, GPC for Mn/Đ, and mass spectrometry (MALDI-TOF) where applicable.

No pharmacopeial status or compendial grade is specified for this item; refer to CoA/Spec Sheet. This product is not approved for human or veterinary use.

Physical Properties

Item-specific numerical specifications are not provided in the Product Data and should be confirmed on the CoA/Spec Sheet. The following notes are general/literature guidance for PEGs of similar chain length (DP ~25) and are not product specifications.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (PEGs in this DP range are commonly waxy solids or viscous oils.)
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet. (Theoretical average for DP ~25 can be estimated by 25 × 44 Da plus end groups; provided as general computation only.)
• Solubility (literature/general):
  • Water: Readily soluble; PEG chains are highly hydrophilic and hydrogen-bonding.
  • Polar organics: Miscible or highly soluble in methanol, ethanol, isopropanol, acetone, acetonitrile, DMSO, DMF; partially soluble in ethyl acetate; poor solubility in nonpolar hydrocarbons.
• Density, refractive index, logP, pKa: Not typically defined for polymer mixtures; Not specified for this item; refer to CoA/Spec Sheet.
• Thermal behavior (literature/general): PEGs exhibit softening/melting transitions that broaden with dispersity. A clear boiling point is not meaningful for polymers; thermal degradation precedes boiling at ambient pressure.
• Hygroscopicity: PEGs are hygroscopic and can absorb moisture; drying prior to moisture-sensitive conjugations is recommended.

Always verify exact numerical properties (Mn, Mw, Đ, residual solvents, water content) on the accompanying documentation for the specific lot.

Quality and Grades

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

• What to expect for PEG conjugation reagents (general guidance)

  • End-group integrity: For m-PEG-propargyl, verify single alkyne functionality and methoxy capping via NMR/FTIR and functional assays (e.g., azide coupling test). End-group purity critically impacts coupling efficiency and stoichiometric control.
  • Molecular-weight characterization: Manufacturers typically report Mn/Mw and dispersity (Đ) by GPC/SEC against PEG standards. A narrower Đ improves batch-to-batch reproducibility in bioconjugation.
  • Residuals and ancillary specs: Water content (Karl Fischer), residual solvents, metals (especially Cu after click reactions), and bioburden/endotoxin (if applicable for sensitive workflows). Not specified for this item; refer to CoA/Spec Sheet.

• Stabilizers/additives

  • PEGs generally do not require stabilizers; no stabilizers are specified for this item.

• Documentation and release testing

  • Request CoA/Spec Sheet for: Mn/Mw/Đ, purity/end-group analysis, residual solvents/water, and recommended analytical methods (1H NMR, MALDI-TOF, GPC).

Select lots with analytical profiles suited to your application (e.g., tighter Mn window for quantitative conjugation, low water for moisture-sensitive couplings).

Reaction and Applications

m-PEG25-Propargyl is designed as a single-alkyne PEGylation handle enabling robust conjugation to azide-bearing partners via click chemistry.

• Core transformations (literature/general)

  • CuAAC (copper(I)-catalyzed azide–alkyne cycloaddition): Forms a 1,4-disubstituted 1,2,3-triazole linkage with azides on small molecules, peptides, proteins (via azidohomoalanine, azido sugars), polymers, and surfaces. High chemoselectivity and tolerance to water and biological buffers.
  • SPAAC compatibility: While this reagent provides the alkyne, SPAAC requires a strained alkyne partner; thus m-PEG25-propargyl participates in SPAAC only if the counterpart is azide and the alkyne is strained—here it is not strained. Use CuAAC for this item.
  • Radical thiol–yne additions: Under photoinitiation or radical conditions, terminal alkynes can add thiols; useful for network formation but less selective than CuAAC.

• Application domains

  • Polymer/surface modification: Grafting PEG to azide-functional polymers, nanoparticles, or oxide surfaces (via azido-silanes) to impart stealth and hydrophilicity.
  • Bioconjugation: PEGylation of azide-labeled biomolecules to improve solubility and reduce nonspecific interactions in assays (research use only).
  • Material assembly: Formation of PEG-triazole linkers in hydrogels and block copolymers.

• Practical notes

  • Use ligated copper(I) (e.g., CuSO4/sodium ascorbate + TBTA/BTTAA/THPTA) to accelerate and minimize protein damage in aqueous systems.
  • Control stoichiometry carefully; single-end functionality simplifies product distribution relative to di-alkyne PEGs.
  • Purify by dialysis, ultrafiltration, or precipitation depending on scale and counterpart.

Reaction Conditions

General CuAAC guidance for terminal alkynes such as m-PEG25-Propargyl (literature/general, not product specifications):

• Typical solvent systems

  • Aqueous or mixed: H2O/t-BuOH (1:1), H2O/EtOH (1:1), H2O/DMSO (up to 20–50% DMSO) to solubilize diverse partners.
  • Anhydrous: DMF or DMSO for moisture-sensitive counterparts.

• Catalyst systems

  • CuSO4·5H2O (0.5–5 mol% vs azide) reduced in situ with sodium ascorbate; add a ligand such as TBTA, THPTA, or BTTAA (0.5–2 equiv relative to Cu) to accelerate and stabilize Cu(I).
  • Alternatively, preformed Cu(I) sources (CuBr, Cu(MeCN)4PF6) under inert atmosphere with appropriate ligands.

• Conditions

  • Temperature: 20–37°C commonly sufficient; lower for sensitive biomolecules.
  • pH: 6.5–8.0 for biomolecular systems; avoid strong chelators (EDTA) during coupling.
  • Time: 0.5–24 h depending on concentration, ligand, and substrate sterics.
  • Concentration: 0.1–10 mM in limiting partner; higher concentrations accelerate but may increase viscosity with PEG.

• Workup and purification

  • Remove copper by dialysis, gel filtration, or chelating resins; precipitate PEG conjugates from antisolvents (e.g., cold ether/acetone) when compatible.
  • Validate completion by IR (loss of N3 stretch ~2100 cm−1) and NMR; SEC to assess Mn shift upon conjugation.

Adjust catalyst loading and ligand choice to balance rate, selectivity, and biocompatibility for your specific system.

Safety and Handling

No specific GHS classification, hazard statements, or pictograms are provided for this item. Consult the SDS for authoritative safety information.

• General hazard profile (PEGs; literature/general)

  • PEGs are generally considered of low acute toxicity and low volatility. Dust generation is minimal for waxy/viscous forms. Terminal alkyne groups can undergo copper-catalyzed reactions; avoid unintended exposures to reactive azides.

• Recommended PPE and lab practices

  • Wear safety glasses, lab coat, and appropriate gloves (e.g., nitrile).
  • Work in a clean, dry area; use a fume hood for weighing/dissolution if using volatile organic solvents or copper catalysts.
  • Avoid inhalation of powders/aerosols and prolonged skin contact.

• Incompatibilities and precautions

  • Strong oxidizers may degrade polyethers.
  • Copper salts, azides, and reducing agents are commonly used with this material in CuAAC; manage according to their SDS. Avoid heavy-metal contamination in downstream biological assays if not desired.
  • PEGs can retain moisture; dry materials and solvents when conducting moisture-sensitive couplings.

• First aid (general)

  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing.
  • Inhalation: Move to fresh air.
  • Ingestion: Rinse mouth; seek medical advice as appropriate.

• Waste disposal

  • Dispose of PEG-containing and copper-containing waste per institutional and local regulations.

Defer to the product SDS for definitive handling and emergency measures.

Solvent Selection

m-PEG25-Propargyl is amphiphilic but predominantly hydrophilic; solvent choice depends on counterparty solubility and the intended conjugation chemistry.

• Polarity and miscibility (literature/general)

  • Highly soluble/miscible: Water, methanol, ethanol, isopropanol, DMSO, DMF.
  • Moderately soluble: Acetonitrile, acetone, ethyl acetate (variable with DP and temperature).
  • Poorly soluble: Nonpolar hydrocarbons (hexane, heptane), chlorinated solvents (often limited).

• Typical use scenarios

  • Aqueous CuAAC: Water or water/t-BuOH, water/ethanol, or water/DMSO blends facilitate azide coupling to biomolecules and surfaces.
  • Organic-phase CuAAC: Anhydrous DMF/DMSO or t-BuOH for hydrophobic substrates.
  • Film casting/coatings: Alcohols or water/alcohol blends for surface modification.

• Practical tips

  • Remove dissolved oxygen for CuAAC by nitrogen purging when minimizing oxidative byproducts is critical.
  • Ensure all components are mutually soluble; co-solvent systems (water + DMSO or t-BuOH) often maximize rates and homogeneity.

• Small comparison (literature/general)

  • Water: Green, biocompatible; may require Cu-ligands for rate/solubility control.
  • t-BuOH/water: Enhances solubilization of hydrophobic partners; easy workup.
  • DMF/DMSO: Broad solubility; ensure low water for strictly anhydrous workflows; consider downstream removal.

Storage and Reconstitution

• Storage conditions (item-specific)

  • Store at -20°C.
  • Shipped in an ice chest with ice pads to maintain low temperature during transit.

• General handling

  • Allow container to equilibrate to room temperature in a desiccator before opening to minimize moisture condensation; PEGs are hygroscopic.
  • Reseal tightly under dry inert gas if possible. Protect from prolonged exposure to air and moisture, especially before moisture-sensitive conjugations.

• Reconstitution and dissolution (general)

  • Solvents: Water, alcohols (MeOH/EtOH/i-PrOH), DMSO, or DMF depending on application. Use sterile, filtered solutions for biological workflows.
  • Typical concentrations: 10–100 mg/mL for stock solutions, adjusted to solubility and viscosity constraints.
  • For CuAAC, prepare fresh solutions of copper salts, ligands, and reductant; avoid storing mixed catalyst solutions.

• Stability considerations

  • Avoid repeated freeze–thaw cycles; prepare aliquots on first opening.
  • Store solutions at 2–8°C short term (hours to days) or at -20°C for longer, as compatible with solvent; verify stability empirically.

• Specifications not provided

  • Appearance, exact molecular weight, water content, and purity are not specified for this item; refer to CoA/Spec Sheet for lot-specific details.

For research use only.

Structure and Identity

m-PEG25-Propargyl is a monomethoxy-terminated poly(ethylene glycol) (mPEG) with an average repeat length of approximately 25 ethylene oxide units and a terminal propargyl (–C≡C–CH2) group for alkyne-based conjugation.

• Item-specific identifiers

  • CAS: M1445672 (internal catalog reference)
  • 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.

• Structural features (general description)

  • Backbone: Polyether chain comprising ~25 –CH2–CH2–O– repeating units (PEG).
  • Termini: One end capped with methoxy (–OCH3); the other end bears a propargyl group (–O–CH2–C≡CH or equivalent linkage depending on spacer design).
  • Functional groups: Ether linkages throughout; terminal terminal alkyne suitable for CuAAC (“click”) and related alkyne chemistries.
  • Architecture: Linear, flexible, highly solvated polymer chain; typically supplied as an average degree of polymerization (DP ≈ 25). Actual dispersity and exact end-group linkage should be confirmed on the CoA.

• 2D structure (verbal)

  • A linear sequence of alternating ethylene and oxygen atoms (–CH2–CH2–O–)n, with a methoxy cap at one end and a propargyl moiety at the other, providing a single-site handle for conjugation while preserving PEG’s hydrophilicity and stealth characteristics.

Synthetic Utility

• Functional design

  • Single propargyl terminus enables high-fidelity, 1:1 conjugation to azides via CuAAC, forming a robust triazole linkage while preserving PEG’s solubilizing properties.
  • Methoxy capping eliminates reactivity at the second terminus, simplifying product distributions versus di-functional PEGs.

• Retrosynthetic value

  • Use as a hydrophilic appendage to introduce water compatibility to small molecules, polymers, and surfaces.
  • Serves as a spacer to distance active pharmacophores, dyes, haptens, or affinity ligands from carriers in research constructs.

• Representative transformations (literature/general)

  • CuAAC with azido-peptides, -proteins, -sugars, -polymers, and -surfaces (azido-silanes on glass/SiO2, azido-alkyl on gold/NPs).
  • Post-click elaboration: The triazole can participate in H-bonding and π-interactions; downstream coupling handles can be embedded on the azide partner.
  • Network formation: Multi-azide crosslinkers can couple to m-PEG-propargyl for star/brush architectures with controlled grafting density.

• Practical analytical notes

  • Monitor reaction progress by disappearance of azide IR band (~2100 cm−1) and appearance of triazole signals in 1H NMR.
  • Quantify substitution degree via UV tags on the azide partner or nitrogen analysis when appropriate.

This reagent streamlines installation of a single PEG chain where site-specificity and hydrophilicity are desired.

Target Specificity

Not applicable. This product is a PEG conjugation reagent and does not possess biological target specificity, antigen binding, clone identity, or species reactivity. For selective coupling, it reacts chemoselectively with azide-functional groups via CuAAC under appropriate conditions.

자주 묻는 질문

How should this product be stored?

Store at ?20 °C. Freezer storage is required to maintain the specified shelf life.

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 are the CAS number, molecular formula and molecular weight?

The CAS Number is M1445672, the molecular formula is C52H102O25, and the molecular weight is 1127.35 g/mol.

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.