mPEG benzaldehyde - MW 20000 Da

Cat. No.: m163983

GRADE & PURITY MW 20000 Da

Storage

Room temperature

Shipped In

Normal

Specifications

Spezifikationen & Reinheit

MW 20000 Da

Storage

Room temperature

Verschickt in

Normal

Application Protocols

No vendor-validated protocols are provided for this SKU. Below is general, non-binding guidance for common aldehyde-based PEGylations (literature/general):

• Reductive amination of lysine residues (protein):
  • Prepare protein in 50 mM phosphate, pH 6.5, 150 mM NaCl. Exchange out amine buffers (avoid Tris/glycine).
  • Dissolve mPEG–benzaldehyde in minimal DMSO and add to 2–10 mM final aldehyde (≤10–20% DMSO v/v).
  • Incubate 2 h at RT, then add NaBH3CN to 5–20 mM with careful handling; continue 2–16 h.
  • Quench, desalt/dialyze, and analyze by SDS-PAGE/SEC.
• Oxime ligation with aminooxy tag:
  • 100 mM sodium acetate, pH 5.0, optional 50 mM aniline catalyst.
  • Mix partners at 1–5 mM aldehyde, RT for 1–3 h; purify by dialysis/SEC.

For exact conditions and performance specifications of this item, refer to the CoA/Spec Sheet and optimize empirically.

Biological Roles

This product is a synthetic polymer reagent rather than a native biomolecule.

• General context (literature/general):
  • PEG is widely used to impart hydrophilicity and steric stabilization to biomolecules and surfaces, reducing nonspecific interactions in vitro.
  • The benzaldehyde terminus enables chemoselective coupling to primary amines (or hydrazide/aminooxy tags) on peptides, proteins, and carbohydrates.
  • Resulting PEGylation can modulate solubility, aggregation, and in vitro stability of conjugates used in biochemical assays or materials research.

No endogenous metabolic or signaling roles are attributed to mPEG–benzaldehyde itself. All uses are for research and laboratory applications only.

Buffer Applications

This material is not a buffer reagent. However, buffer choice is critical for its conjugation chemistry (literature/general guidance):

• Avoid buffers containing primary/secondary amines (e.g., Tris, glycine), which quench the aldehyde.
• Suggested systems:
  • Acetate or citrate buffer (50–200 mM, pH 4.5–6.0) for hydrazone/oxime ligation; optional aniline catalyst (10–100 mM).
  • Phosphate buffer (50–100 mM, pH 6.0–7.0) for imine formation followed by reductive amination (e.g., NaBH3CN or alternative reductants). Maintain low headspace oxygen when possible to limit aldehyde oxidation.
• Ionic strength and additives: Include 100–150 mM NaCl for protein stability if compatible; add 0.01–0.05% nonionic surfactant only if required and verified not to interfere.

Green Alternatives

Aldehyde-mediated ligations are water-compatible and can minimize hazardous reagents when thoughtfully designed.

• Greener practice within aldehyde chemistry (literature/general):
  • Prefer hydrazone/oxime ligation in aqueous acetate/citrate buffers (pH 4.5–6.0) to avoid cyanoborohydride; reactions can be catalyzed by aniline or o-aminobenzoic acid at millimolar levels.
  • Run at ambient temperature in water-rich media, minimizing high-boiling aprotic solvents (DMF, NMP). Use bio-based ethanol as a cosolvent if needed.
• Alternatives comparison (literature/general):
  • NHS-PEG: efficient but often requires organic solvents and produces N-hydroxysuccinimide waste; hydrolysis limits atom economy.
  • Maleimide-PEG: selective for thiols but sensitive to hydrolysis and retro-Michael; often requires pH control and deoxygenation.
  • SPAAC (DBCO-PEG/azido): copper-free click with excellent selectivity; typically more benign but synthetic footprints can be higher.

Small comparison (literature/general):

• Aldehyde–amine (with reduction): aqueous, widely accessible nucleophiles; may need cyanoborohydride (hazard) unless alternative reductants used.
• Aldehyde–hydrazide/oxime: aqueous, no reductant, reversible but sufficiently stable for many uses; catalytic aniline improves rates.
• SPAAC: clean, no metals, excellent in complex media; requires azide/strained alkyne partners.

Pharmaceutical Uses

No pharmacopeial status or excipient grade is specified for this item; refer to CoA/Spec Sheet. Content below is general, non-clinical information.

• General formulation role (literature/general):
  • mPEG–benzaldehyde is used in research settings to prepare PEGylated conjugates via aldehyde chemistry, which can influence solubility and handling of actives in pre-formulation studies.
  • The PEG segment can act as a hydrophilic pendant, steric stabilizer, or spacing unit in in vitro delivery systems and materials prototyping.
• Manufacturing considerations (general):
  • Control of average Mn and dispersity (Đ) improves batch-to-batch performance in conjugation yields and physical properties.
  • Residual solvent limits and bioburden/endotoxin specifications are critical for any work approaching bioprocess development; not specified for this item.

All uses are for research and laboratory applications only. No medical or clinical claims are made.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (PEGs can range from low-viscosity liquids to waxy solids depending on Mn; literature/general.)
• Average molecular weight (Mn): Not specified for this item; refer to CoA/Spec Sheet.
• Polydispersity (Đ): Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (literature/general):
  • Highly soluble in water, alcohols (MeOH, EtOH), and polar aprotic solvents (DMSO, DMF, NMP).
  • Limited solubility in nonpolar hydrocarbons.
• Thermal behavior (literature/general):
  • Glass transition (Tg) typically around −50 to −60 °C for PEG; melting point and viscosity rise with Mn.
  • Benzaldehyde end-group introduces UV absorption; PEG backbone is largely UV-transparent above ~220 nm (literature/general qualitative note).
• Density, refractive index, BP/MP, pKa/logP: Not specified for this item; refer to CoA/Spec Sheet. (For polymers, discrete BP is not applicable; thermal softening/melting observed instead.)
• UV characteristics (literature/general): Aromatic aldehydes show π→π* absorption in the ~240–280 nm range; intensity scales with concentration of terminal groups.

Quality and Grades

• Grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
• What to look for in mPEG–benzaldehyde (general guidance):
  • Functional end-group content (aldehyde substitution), commonly reported as mol% of polymer chains bearing the active aldehyde (>90–95% typical for high-quality materials; literature/general).
  • Average molecular weight (Mn) and dispersity (Đ) from GPC/SEC; tighter Đ (e.g., 1.05–1.20) improves reproducibility in conjugation (literature/general).
  • Residual solvents/monomers and low-ash content for sensitive bioconjugations (literature/general).
  • Low UV background from PEG backbone; aromatic end-group provides quantitation handle by UV or 1H NMR (literature/general).
• Stabilization and handling (general): No stabilizer is typically required, but protection from light and air reduces aldehyde oxidation. If specifications for stabilizers or inhibitors apply to this SKU, they will be listed in the CoA/Spec Sheet.
• Documentation: For lot-specific Mn, Đ, functionality, and residuals, consult the CoA. These parameters directly affect stoichiometry in conjugation workflows.

Reaction and Applications

This reagent provides an aldehyde handle for chemoselective PEGylation and materials assembly.

• Primary uses (literature/general):
  • Formation of imines (Schiff bases) with primary amines on peptides, proteins, and small molecules; typically stabilized by in situ reductive amination (NaBH3CN, pic-BH3CN) to yield secondary amines.
  • Hydrazone and oxime ligations with hydrazide or aminooxy partners; proceed efficiently at mildly acidic pH, often accelerated by aniline catalysts.
  • Dynamic covalent crosslinking for hydrogel formation using bis-hydrazide or bis-aminooxy crosslinkers; reversible unless reduced.
• Practical tips (general):
  • Avoid amine-containing buffers (e.g., Tris, glycine) during coupling; use acetate (pH 4.5–6.0) for hydrazone/oxime or phosphate (pH 6–7) for reductive amination.
  • Determine stoichiometry based on average Mn and functionalization; use a modest excess of mPEG–ald (e.g., 2–10 equiv per amine site) for biomolecule PEGylation.
  • For proteins, maintain mild conditions (room temperature, isotonic buffers); add DMSO ≤10–20% v/v if needed for solubility.
• Example application scenarios (literature/general):
  • Site-selective PEGylation of N-termini (pH ~6.0 reduces Lys side-chain reactivity).
  • Surface immobilization by reacting amine-presenting substrates with mPEG–ald to create nonfouling PEG brushes while anchoring via imine/hydrazone chemistry.
  • Introduction of a single PEG chain onto amine-bearing small molecules to modulate aqueous solubility.

Reaction Conditions

General literature guidance for aldehyde-based PEGylation (optimize per system):

• Imine formation + reductive amination (amines):
  • Solvent/buffer: 50–100 mM phosphate, pH 6.0–7.0; optional 0–20% DMSO for solubility.
  • Stoichiometry: 2–10 equiv mPEG–ald per target amine for biomolecules; near-stoichiometric for small molecules when neat or high concentration.
  • Temperature/time: RT to 30 °C, 1–16 h for imine formation; add NaBH3CN or alternative mild reductant, continue 2–16 h (literature/general). Use appropriate safety measures for cyanoborohydride.
• Hydrazone/oxime ligation (hydrazide/aminooxy):
  • Buffer: 50–200 mM acetate or citrate, pH 4.5–6.0; aniline catalyst (10–100 mM) can accelerate rates.
  • Temperature/time: RT, 0.5–6 h typical; reaction is reversible; can be driven by slight excess of one partner or by removal (e.g., dialysis) (literature/general).
• Concentrations: 0.1–10 mM aldehyde end-group typical in small-molecule work; for proteins, 0.1–5 mg/mL protein with 1–50 mM aldehyde end-group, depending on desired degree of modification (literature/general).
• Workup and analysis:
  • Remove excess polymer by dialysis/SEC for biomolecules; precipitate or chromatography for small molecules.
  • Confirm modification by MS (where feasible), SDS-PAGE shift, SEC-MALS, or NMR for small molecules.

Note: Exact yields and kinetics depend strongly on Mn, end-group content, substrate accessibility, and buffer composition.

Safety and Handling

• GHS classification, signal word, H-statements, pictograms: Not specified for this item; refer to SDS for authoritative safety information.
• General hazards (literature/general):
  • PEG backbone is generally considered of low acute toxicity and low volatility.
  • The benzaldehyde end-group is an electrophile; may cause irritation to skin, eyes, and respiratory tract; can undergo oxidation to benzoic acid.
• PPE: Wear lab coat, nitrile gloves, and safety glasses; use in well-ventilated area or fume hood, especially when weighing/pipetting powders or preparing concentrated solutions.
• Incompatibilities (literature/general):
  • Avoid strong oxidizers (risk of aldehyde oxidation) and strong bases/acids that can degrade PEG or the aldehyde.
  • Avoid primary/secondary amines, hydrazines, hydroxylamines in storage containers or buffers to prevent premature conjugation.
• Special risks (literature/general): Aldehyde functionality can form imines/hydrazones/oximes; moisture and alcohols can form hemiacetals/acetals under acidic conditions.
• First aid (general): Rinse skin/eyes with water for at least 15 minutes if contacted; remove contaminated clothing; if inhaled, move to fresh air; if ingested, rinse mouth. Seek medical attention as needed. Always consult SDS.

Solvent Selection

mPEG benzaldehyde is a polar, hydrogen-bond accepting polyether that dissolves readily in water and polar organics.

• Polarity/miscibility (literature/general):
  • Excellent solubility: water, PBS (amine-free), acetate, citrate buffers; DMSO, DMF, NMP, methanol, ethanol, isopropanol.
  • Limited in acetone/ethyl acetate depending on Mn; poor in alkanes/ethers at high Mn.
• Choosing solvents for conjugation (general):
  • For protein/peptide amines: use aqueous acetate or phosphate buffers (pH 5.0–7.0) without primary/secondary amines (avoid Tris, glycine) to prevent quenching of the aldehyde.
  • For small-molecule amines: anhydrous MeOH/EtOH or aprotics (DMSO/DMF) with a small amount of acid catalyst (for hydrazone/oxime) or buffered near-neutral conditions for reductive amination.
• Cosolvent strategies (general):
  • For higher-Mn materials, prepare a DMSO or DMF concentrate, then dilute into aqueous buffer to the desired final organic fraction (5–20%).
• Quick comparison (literature/general):
  • Versus NHS-PEG: aldehyde chemistry is compatible with aqueous buffers and can be reversible (imine) or permanent (after reduction), while NHS esters require pH 7.5–8.5 and are moisture sensitive.
  • Versus maleimide-PEG: aldehyde targets amines (ubiquitous); maleimide is thiol-selective and more pH-sensitive.

Storage and Reconstitution

• Storage conditions (as provided): Room temperature. Ship: Normal. For research use only.
• Additional handling guidance (literature/general):
  • Store tightly sealed in a dry container, protected from light to minimize aldehyde oxidation. Inert gas blanket (e.g., nitrogen) can further preserve the end-group.
  • Avoid contact with amines, hydrazides, and hydroxylamines during storage (including in caps/liners) to prevent premature reaction.
• Reconstitution (general):
  • Prepare stock solutions in water, PBS (amine-free), acetate buffer, or polar organics (DMSO/DMF/alcohols) depending on application. Use dry, oxygen-reduced solvents when feasible.
  • Typical stock concentrations: 10–200 mM with respect to aldehyde end-group; filter through 0.22 μm if needed for bioconjugation.
  • For aqueous use, dissolve first in a small volume of DMSO/DMF if higher-Mn material dissolves slowly, then dilute into buffer.
• Solution stability (general): Aldehyde can slowly oxidize or hydrate in water; prepare fresh solutions when possible. If storage of solutions is necessary, keep in amber vials, minimize headspace, and refrigerate as appropriate for your workflow. Solid-state storage per product data is at room temperature.

Structure and Identity

mPEG benzaldehyde is a methoxy-terminated poly(ethylene glycol) bearing a terminal benzaldehyde functionality used for aldehyde–amine conjugation chemistry.

• Item-specific identifiers (CAS, InChIKey, SMILES, exact average Mn): Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight (average, polymer): Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula (polymer, repeating unit): General repeating unit for PEG is –CH2–CH2–O–; terminal groups are a methoxy cap at one end and a benzaldehyde-functional aryl at the other (literature/general description).
• Structural features (general):
  • Linear PEG backbone (polyether) with methoxy cap (–O–CH3) at one terminus (mPEG).
  • Aldehyde-functional aromatic end-group (benzaldehyde: –C6H4–CHO) providing chemoselective reactivity toward nucleophiles (amines, hydrazides, aminooxy) via imine/hydrazone/oxime formation (literature/general).
  • Polydisperse polymer; properties depend on average molecular weight (Mn) and dispersity (Đ) (literature/general).
• 2D structure in words (general): a flexible –(CH2–CH2–O)n– chain capped with –O–CH3 at one end, and with an aryl ring carrying a formyl group (–CHO) at the other; the PEG chain is connected to the aryl through an ether or benzylic linkage depending on synthesis route (literature/general).

Synthetic Utility

mPEG–benzaldehyde is a versatile monofunctional polymer reagent for introducing a PEG chain via aldehyde ligation chemistry.

• Functional group reactivity (literature/general):
  • Aldehyde electrophile forms imines with primary amines; hydrazones with hydrazides; oximes with aminooxy groups. Subsequent reduction fixes imines as stable C–N bonds.
  • The PEG ether backbone is chemically inert under mild conditions, providing a solubilizing and nonionic spacer.
• Retrosynthetic value (general):
  • Enables late-stage PEGylation of amine-bearing scaffolds without protecting groups, often under aqueous conditions.
  • Serves as a handle for assembling PEGylated materials (e.g., hydrogels/crosslinked networks using bis-nucleophiles) and surface modification (amine-functional surfaces).
• Complementarity to other handles (general):
  • Orthogonal to thiol-selective (maleimide) and azide–alkyne click chemistry; useful in multi-step, orthogonally addressable conjugation schemes.
• Characterization tips (general):
  • 1H NMR: aldehyde proton (~9–10 ppm) and aromatic protons confirm end-group presence; PEG methylenes (~3.4–3.8 ppm). UV at ~250–280 nm provides qualitative aldehyde end-group signal.
  • SEC/GPC for Mn and Đ; MALDI-TOF can provide distribution information for lower-Mn PEGs.

Target Specificity

Not applicable. This product is a chemical reagent (polymer) and not a biological targeting reagent. No antigen/epitope or species specificity applies. Item-specific targeting data: Not specified for this item.

Häufig gestellte Fragen

How should this product be stored?

Store at room temperature.

How is this product shipped?

This product ships under standard ambient conditions. No temperature-controlled packaging is required.

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.