TCO-PEG2-amine - ≥95% , CAS No.2141981-87-3

CAS: 2141981-87-3 Cat. No.: T597017 Summenformel: C₁₅H₂₈N₂O₄ Molekulargewicht: 300.4 PubChem CID: 146026020

QUALITÄT & REINHEIT ≥95%

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Application

227,228,229

Übersicht

TCO-PEG2-amine contains a TCO moiety and a free amine. This reagent can be used to derivatize carboxyl groups or activated esters (e.g. NHS esters) through a stable amide bond in the presence of of activators (e.g. EDC, or DCC). The hydrophilic PEG linker increases the solubility of compounds in aqueous media.

Spezifikationen

Spezifikationen & Reinheit

≥95%

Storage

Store at -20°C

Verschickt in

Ice chest + Ice pads

Dieses Produkt erfordert Kühlkettenversand. Grundversand und andere Economy-Optionen sind nicht verfügbar.

Reinheit

≥95%

Namen und Kennungen

Kanonisches Lächeln

C1CC=CCCC(C1)OC(=O)NCCOCCOCCN

IUPAC Name

[(4Z)-cyclooct-4-en-1-yl] N-[2-[2-(2-aminoethoxy)ethoxy]ethyl]carbamate

InChIKey

XCPPYCGUCZZMQS-UPHRSURJSA-N

INCHI

1S/C15H28N2O4/c16-8-10-19-12-13-20-11-9-17-15(18)21-14-6-4-2-1-3-5-7-14/h1-2,14H,3-13,16H2,(H,17,18)/b2-1-

PubChem CID

146026020

Molekulargewicht

300.4

Chemische und physikalische Eigenschaften

• Löslichkeit: Solubility in DMSO, DCM, DMF

Application Protocols

No vendor-tested application protocols are provided for this specific item. Below is general literature-style guidance for common uses; adjust to your system and consult primary references.

Example: Installing TCO on a protein via NHS-ester route (general)

• Prepare protein at 1–5 mg/mL in PBS or HEPES, pH 7.5–8.0.
• Dissolve TCO-PEG2-amine in anhydrous DMSO (10–50 mM). Keep protected from light.
• Activate a carboxyl-containing NHS ester (or use an NHS-ester functionalized intermediate) and add 2–10 equiv relative to target sites.
• Incubate 0.5–2 h at 4–25°C with gentle mixing; maintain ≤10% DMSO in final.
• Quench residual NHS ester with Tris or glycine if needed.
• Purify by desalting (e.g., Sephadex G-25) or spin filtration (10–30 kDa MWCO).
• Quantify TCO incorporation by reacting an aliquot with a known excess of tetrazine and monitoring tetrazine absorbance decrease.

Note: These are general guidelines only; verify stability and activity of your biomolecule under chosen conditions. No guarantees of performance are implied.

Biological Roles

This compound is not a natural metabolite and does not have intrinsic biological roles. Instead, it is a chemical tool used in bioorthogonal chemistry.

General context (literature):

• Bioorthogonal handle: The TCO moiety acts as a reactive tag for selective ligation with tetrazines in complex biological environments without perturbing native biochemistry.
• PEG2 spacer: The short PEG linker enhances aqueous compatibility and can reduce nonspecific interactions versus purely hydrophobic linkers, aiding labeling in protein-rich media.
• Use cases: Installation on proteins, nucleic acids (via amine-reactive intermediates), lipids, and materials to enable rapid, catalyst-free conjugation under physiological conditions.

Notes:

• This product is intended strictly for research use. No clinical or diagnostic claims are made or implied.
• When applying in biological systems, confirm biocompatibility of solvents and any activating chemistries used for attachment (e.g., NHS-ester couplings) to avoid perturbation of samples.

Buffer Applications

Not typically used as a buffering agent. TCO-PEG2-amine has no defined buffering range and is not employed to control pH.

Practical guidance (general):

• For bioconjugation via the amine, HEPES, PBS, or borate buffers at pH 7.5–8.5 are commonly used to support reactions with NHS esters or EDC/sulfo-NHS activated carboxylates (literature). Maintain low light during manipulations to protect the TCO.
• Use minimal organic cosolvent (e.g., ≤10% DMSO) to aid solubility while maintaining protein integrity in aqueous systems.

Green Alternatives

Context: The principal environmental considerations involve solvent choice and minimizing excess reagent in bioconjugation.

Greener choices (literature-based guidance):

• Solvents: Prefer water-rich media with minimal DMSO/DMF where feasible. Ethanol or 2-propanol can sometimes substitute for DMF in amide couplings when using water-tolerant coupling agents.
• Coupling agents: Use EDC/sulfo-NHS in buffered aqueous media to couple the amine to carboxylates, reducing reliance on hazardous solvents. Avoid carbodiimides in neat DMF when aqueous options suffice.
• Process intensification: Employ micro- or semi-batch additions to reduce excess of TCO-PEG2-amine and improve atom economy.

Small comparison (general):

• Conventional: DMF/DCM, DIC/HOBt or HATU; higher waste and hazard.
• Greener: Aqueous MES/HEPES buffers with EDC/sulfo-NHS or modern Oxyma-based systems in water/EtOH.

Trade-offs:

• Aqueous systems may increase hydrolysis of activated esters; mitigate by cooling, rapid addition, and in situ activation.
• Replacing DMF with ethanol/water can affect solubility; brief DMSO cosolvent (≤10%) often resolves this with acceptable EHS profile.

Waste handling:

• Collect amide coupling residues and tetrazine-containing wastes separately; many tetrazines are colored and can be tracked by spectrophotometry to ensure adequate deactivation prior to disposal (follow institutional guidelines).

Pharmaceutical Uses

No excipient or pharmacopeial status is specified for this item; refer to CoA/Spec Sheet. This product is supplied for research use only.

General research/manufacturing context (literature):

• Conjugation handle: Employed during R&D to install a TCO group on biomolecules or polymers that will later undergo tetrazine click for payload attachment, affinity tagging, or imaging probe assembly.
• Process development: Useful in screening linker lengths and hydrophilicity for bioconjugates, including antibody and nanoparticle prototypes.
• Analytics: Serves as a standard for evaluating tetrazine reactivity and stability in formulation studies.

Important note: No medical, clinical, or therapeutic claims are made. Any use in GMP settings would require separate qualification, specifications, and compliance with relevant pharmacopeial and regulatory standards.

Physical Properties

Item-specific physical 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/Boiling Point: Not specified for this item; refer to CoA/Spec Sheet.
• Density/Refractive Index: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility: Not specified for this item; refer to CoA/Spec Sheet.

General/literature expectations for TCO–PEG–amines (informational, not item specifications):

• Solubility trend: Good solubility in polar aprotic solvents (DMSO, DMF) and mixed aqueous/organic systems due to PEG2; variable solubility in pure water depending on exact substitution.
• pKa (α-amine): Typical primary aliphatic amines pKaH ~9–10 (literature); protonation increases water solubility.
• Reactivity considerations: TCO is prone to photoisomerization to the less reactive cis isomer under UV/visible light and to acid- or metal-catalyzed isomerization; protect from light and strong acids.

Practical notes (general):

• Prepare stock solutions in anhydrous DMSO or DMF to minimize hydrolysis of electrophilic counterparts during conjugation.
• If required for aqueous use, pre-dilute organic stock into buffered saline immediately before use to limit TCO isomerization and undesired side reactions.

Quality and Grades

Item-specific quality information:

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

General guidance on quality attributes for TCO-PEG-amine reagents:

• Purity considerations: For bioorthogonal conjugation, a high purity of the trans isomer is critical. Minor amounts of the cis isomer reduce ligation rates with tetrazines. Vendors often control E:Z isomer ratio and residual solvents; verify via CoA.
• Residual metals/ions: Low metal content is preferred as certain metals catalyze TCO isomerization. If metal limits matter for your application, request the specific certificate.
• Water/peroxides: Not specified for this item. In general, ensure low moisture for amide couplings and storage stability; peroxides are not typical concerns for PEGylated amines but confirm by spec if relevant.
• Analytical verification: 1H/13C NMR (diagnostic alkene signals), LC–MS for mass confirmation, and chiral/GE determinations if applicable. For tetrazine reactivity, a functional assay (pseudo-first-order rate in solution) can be informative.

What the grade implies (general):

• Research grade materials are suitable for R&D and in vitro work; they are not qualified for clinical use. HPLC-verified materials typically exhibit low UV background suitable for analytical workflows.

Reaction and Applications

Core reactivity (literature):

• Bioorthogonal ligation: TCO undergoes ultrafast inverse-electron-demand Diels–Alder (IEDDA) cycloadditions with 1,2,4,5-tetrazines, forming dihydropyridazine intermediates that tautomerize/oxidize to stable adducts. Reported second-order rate constants for optimized TCO–tetrazine pairs can reach ~10^4–10^6 M−1 s−1 in aqueous media, enabling rapid labeling at low micromolar concentrations.
• Orthogonality: The reaction proceeds without catalysts and is tolerant to water, oxygen, and most biomolecular functionalities, making it ideal for late-stage bioconjugation.

Applications:

• Protein/antibody modification: Use the terminal amine to form amides (e.g., with activated esters) or ureas (with isocyanates), installing a TCO handle for subsequent tetrazine click labeling.
• Surface and polymer functionalization: Introduce TCO onto nanoparticles, hydrogels, or device surfaces for post-functionalization with tetrazine-bearing payloads.
• Multistep assembly: PEG2 spacing reduces steric hindrance and can improve accessibility of the TCO during labeling of crowded biomolecular sites.

Practical considerations:

• Protect from light to minimize TCO → cis isomerization; work quickly and at ambient or lower temperatures.
• For bioconjugation, control stoichiometry (e.g., 2–10 equiv per lysine-accessible site), pH 7.5–8.5 for NHS-ester couplings, and remove excess reagent by desalting or SEC.
• Validate TCO content by tetrazine quench assays or UV–Vis readouts of tetrazine bleaching (literature practice).

Reaction Conditions

General conditions (literature; adjust per substrate):

1. Amide coupling via NHS esters:

• Solvent/Buffer: PBS, HEPES, or borate buffer pH 7.5–8.5 with 0–10% DMSO.
• Stoichiometry: 2–10 equiv TCO-PEG2-amine per activated site for proteins; 1.1–1.5 equiv for small-molecule couplings.
• Temperature/Time: 4–25°C, 0.5–2 h for proteins; 25°C, 1–4 h for small molecules.
• Workup: Desalt or spin-filter proteins; extract and concentrate small-molecule products.

2. EDC/sulfo-NHS coupling to carboxylates:

• Buffer: MES (pH 5.0–6.0) for activation, then adjust to pH 7.2–7.5 upon adding the amine.
• Additives: Sulfo-NHS (5–10 mM) improves efficiency in aqueous systems.

3. IEDDA click with tetrazines (after installing TCO):

• Medium: Aqueous buffer or mixed organic/aqueous; catalyst-free.
• Kinetics: Apparent k2 typically 10^3–10^6 M−1 s−1 depending on tetrazine structure and TCO substitution (literature).
• Temperature: 4–37°C; reaction is generally fast at room temperature.

Handling considerations:

• Minimize light exposure; amber vials and foil wrapping are recommended.
• Avoid strong acids and certain transition metals that may catalyze TCO isomerization.
• Validate extent of labeling via LC–MS, UV–Vis (tetrazine consumption), or functional assays.

Safety and Handling

Item-specific hazard information:

• Signal Word: Not specified for this item; refer to SDS.
• H-Statements: Not specified for this item; refer to SDS.
• GHS Classification/Pictograms: Not specified for this item; refer to SDS.

General safety guidance for PEGylated amines and strained alkenes (informational):

• Irritation: Primary amines may cause skin/eye/respiratory irritation. Avoid inhalation of dust/aerosols and contact with skin or eyes.
• Photoisomerization: TCO can isomerize to the cis isomer on light exposure; store and handle under low light/amber conditions.
• Incompatibilities: Strong oxidizers, strong acids (can catalyze isomerization), and acylating agents (unintended reaction at the amine). Avoid copper salts if not intended, as some metals can catalyze isomerization.
• PPE: Lab coat, nitrile gloves, safety glasses; work in a chemical fume hood.
• First aid (overview): If on skin/eyes, rinse with water for several minutes; if inhaled, move to fresh air; if ingested, rinse mouth and seek medical attention. Always follow institutional protocols.

Authoritative guidance: Consult the product’s SDS for definitive hazard classifications, exposure limits, spill response, disposal, and transport information. For bioorthogonal ligations, use clean, inert glassware to avoid unintended catalytic isomerization.

Solvent Selection

Applicability: As a small amphiphilic molecule with a PEG2 spacer and a primary amine, TCO-PEG2-amine is typically handled in polar organic solvents and mixed aqueous systems.

General/literature guidance (not item specifications):

• Preferred stock solvents: Anhydrous DMSO or DMF for preparing concentrated stocks (10–100 mM) to support conjugations with NHS esters, activated carbonates, or isocyanates.
• Aqueous compatibility: The PEG2 chain improves miscibility; buffered saline (pH 7.2–7.5) with 5–20% DMSO or ethanol can facilitate immediate use in bioconjugation.
• Avoid: Strongly acidic media (promotes TCO isomerization) and prolonged exposure to neat water at elevated temperature if long-term stability is required.

Comparison (literature-based):

• TCO-PEG2-amine vs. hydrophobic TCO-amines: PEG2 variant offers better solubility and lower nonspecific binding in biomolecule conjugations.
• TCO-PEG2-amine vs. longer PEGs (PEG4–PEG12): Shorter linker minimizes steric distance but may reduce aqueous solubility compared with longer PEGs; selection depends on target accessibility.

Practical tips:

• Filter or centrifuge to remove particulates before sensitive applications.
• For protein conjugation, pre-dissolve in DMSO and add dropwise to buffered protein solutions to keep final cosolvent ≤10% v/v.

Storage and Reconstitution

Item-specific conditions:

• Storage: Store at −20°C (from Product Data). Protect from light.
• Shipping: Shipped in ice chest + ice pads (from Product Data).

General handling and reconstitution (informational, not item specifications):

• Light protection: Use amber vials and minimize exposure to ambient light to preserve the trans-cyclooctene configuration.
• Reconstitution: Prepare concentrated stocks in anhydrous DMSO or DMF (e.g., 10–100 mM). For immediate aqueous use, dilute into buffer just before application to limit potential isomerization or side reactions.
• Aliquoting: Dispense single-use aliquots to avoid repeated freeze–thaw cycles; store tightly capped under inert gas if feasible to limit oxidation/moisture ingress.
• Stability: Long-term stability depends on solvent, temperature, and light exposure; consult CoA/SDS for any item-specific stability data.

Research use only: Not for human or veterinary use. Dispose of contents/container in accordance with institutional and regional regulations.

Structure and Identity

Overview: TCO-PEG2-amine is a bifunctional small molecule featuring a strained trans-cyclooctene (TCO) moiety for ultrafast bioorthogonal ligation and a primary amine connected through a short polyethylene glycol (PEG2) spacer for conjugation to electrophiles (e.g., NHS esters, activated carbonates).

Item-specific identifiers (from Product Data):

• CAS: 2141981-87-3
• CID (PubChem): 146026020
• InChIKey: 414453 (as provided)
• 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 of this class):

• Core ring system: trans-cyclooctene (8-membered alkene, high ring strain; E-alkene geometry).
• Linker: PEG2 (two ethylene glycol units, –O–CH2–CH2–O–CH2–CH2–), providing hydrophilicity and spacing.
• Terminal functionality: Primary amine (–NH2), typically as the free base; nucleophilic and suitable for amide/urethane formation.
• 2D structure in words: A trans-cyclooctene ring is tethered via an ether-based PEG2 chain to a terminal –CH2–NH2 group. The linker imparts flexibility and aqueous compatibility while preserving the TCO’s reactivity toward tetrazines.

Notes:

• Where exact stereochemical descriptors and substitution patterns are required for registration or modeling, consult the item’s CoA/Spec Sheet. The presence of the trans double bond in cyclooctene is critical for fast inverse-electron-demand Diels–Alder (IEDDA) reactions.

Synthetic Utility

Functional groups and reactivity (general):

• Primary amine: Nucleophilic; forms amides with activated esters (NHS, PFP), ureas with isocyanates, carbamates with activated carbonates, and can be reductively alkylated with aldehydes/ketones.
• PEG2 linker: Provides spacing and increased polarity, improving solubility and reducing aggregation during coupling steps.
• TCO alkene: Highly reactive toward tetrazines via IEDDA; relatively inert to many nucleophiles/electrophiles under neutral conditions, allowing orthogonal chemistry.

Retrosynthetic value:

• Serves as a modular linker to introduce a TCO handle into complex molecules post-synthesis, deferring the tetrazine coupling to a late stage.
• Enables two-stage ligations: first, amide formation through the amine; second, rapid tetrazine click to install labels, crosslinkers, or functional payloads.

Named/related reactions (literature):

• Inverse-electron-demand Diels–Alder (TCO + tetrazine).
• NHS-ester coupling (amide formation) in aqueous buffer.
• EDC/sulfo-NHS mediated carboxyl–amine coupling.
• CDI or p-nitrophenyl carbonate-mediated carbamate formation for linkage to alcohol-bearing substrates.

Practical tips:

• Conduct amide couplings at pH 7.5–8.5 to balance amine nucleophilicity and minimize hydrolysis; remove excess reagent by SEC/desalting.
• Protect from light throughout to preserve the trans configuration of the cyclooctene.

Target Specificity

Not applicable. This product is a small-molecule linker/handle and does not possess inherent biological target specificity, antigen recognition, clone, or isotype. For biomolecular conjugates derived from this reagent, target specificity is determined by the biomolecule to which it is attached (e.g., antibody, peptide, ligand).

Häufig gestellte Fragen

What is the purity of this product?

This product is supplied at ≥95% purity (chemical assay). Lot-specific values are stated on the Certificate of Analysis.

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 2141981-87-3, the molecular formula is C15H28N2O4, and the molecular weight is 300.4 g/mol. InChIKey XCPPYCGUCZZMQS-UPHRSURJSA-N.

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.