| Size | Price | Stock | Qty |
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| 100mg |
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| 250mg |
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| Other Sizes |
| Targets |
This compound functions as a chemical linker for bioconjugation; it does not directly bind to biological receptors or enzymes.
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| ln Vitro |
ADC cytotoxins are connected to antibodies through an ADC connector to form ADCs [1].
Boc-aminooxy-amide-PEG4-propargyl is a non-cleavable 4-unit polyethylene glycol (PEG) linker commonly employed in the synthesis of antibody-drug conjugates (ADCs) and PROTACs. The Boc protecting group is base-labile and can be removed under acidic conditions (e.g., 20-50% trifluoroacetic acid (TFA) in dichloromethane (DCM) or TFA in water) to reveal the reactive aminooxy group. This aminooxy group can then form stable oxime linkages with aldehydes or ketones, providing a chemoselective conjugation strategy under mild, aqueous conditions (pH 4-6). The propargyl group enables copper-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry with azide-functionalized molecules. The dual orthogonal functionality allows for sequential or simultaneous conjugation of two different molecules to the same linker. The PEG4 spacer provides water solubility and flexibility, reducing steric hindrance. As a non-cleavable linker, the bonds formed are stable under physiological and lysosomal conditions; degradation of the conjugate is required for payload release. The linker has no inherent biological activity. |
| ln Vivo |
As a linker, Boc-aminooxy-amide-PEG4-propargyl is not designed to have direct in vivo activity. The in vivo efficacy is determined by the complete conjugate (e.g., ADC or PROTAC) synthesized using this linker. For ADCs, non-cleavable linkers offer high plasma stability and low premature payload release, which can reduce systemic toxicity. However, they require internalization and degradation of the entire conjugate for payload release, which may result in a lower bystander effect. The PEG4 spacer improves solubility and may reduce ADC aggregation, leading to better pharmacokinetics (longer half-life) and reduced immunogenicity. For PROTACs, the linker length and composition (PEG4) can influence the formation of the ternary complex (target protein, PROTAC, E3 ligase) and degradation efficiency. The Boc-protected aminooxy group allows for selective deprotection and subsequent conjugation after the linker is attached to one component, enabling modular synthesis. No direct in vivo activity data for this linker alone is available.
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| Enzyme Assay |
As a chemical linker, Boc-aminooxy-amide-PEG4-propargyl is characterized by chemical assays. The purity (≥95%) is confirmed by HPLC. The structure is verified by ¹H NMR spectroscopy and high-resolution mass spectrometry (HRMS). ¹H NMR (CDCl3, 400 MHz) shows: the Boc group as a singlet at delta ~1.4 ppm (9H, -C(CH3)3), PEG protons as multiplets at delta 3.5-3.7 ppm (-O-CH2-CH2-O-), the amide proton as a broad singlet at delta ~6.5-7.5 ppm, and the propargyl group as a triplet at delta ~2.5 ppm (≡C-H) and a singlet at delta ~2.5 ppm for the terminal alkyne. The molecular weight is confirmed by ESI-MS. The Boc group content is quantified by acid-catalyzed hydrolysis followed by gas chromatography (GC) analysis of the released isobutylene or by ¹H NMR integration. The aminooxy group content is quantified by reaction with a standard aldehyde or ketone after Boc deprotection. The Boc deprotection efficiency is assessed by treating the compound with TFA (20-50% in DCM) for 1-2 hours at room temperature, then analyzing the product by LC-MS to confirm the disappearance of the Boc group. The free aminooxy group is then tested for oxime ligation with a model aldehyde (e.g., 4-formylbenzoic acid) in 100 mM sodium acetate buffer (pH 4.5) or PBS (pH 6.8) at room temperature, monitoring product formation by LC-MS. The propargyl group is quantified by CuAAC reaction with a model azide (e.g., benzyl azide) in the presence of CuSO4 (0.5-1 mM) and sodium ascorbate (1-2 mM) in PBS or t-butanol/water at room temperature, monitoring product formation by HPLC.
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| Cell Assay |
As a linker, Boc-aminooxy-amide-PEG4-propargyl is not used directly in cell-based assays. The final conjugate (e.g., ADC or PROTAC) is tested. For PROTACs synthesized using this linker, a typical cell-based assay involves treating target cells with varying concentrations of the PROTAC (0.001-10 microM) for 4-24 hours. Cells are then lysed, and the levels of the target protein are measured by Western blotting. The DC50 (half-maximal degradation concentration) is calculated. For ADCs, the assay is similar to that of any ADC: cells are treated with the ADC for 72-120 hours, and cell viability is measured by CellTiter-Glo. The free linker (without the protecting group) can be used as a control to ensure no biological activity. The orthogonal conjugation capabilities allow for the synthesis of dual-labeled probes (e.g., a fluorophore attached via oxime ligation and a targeting ligand attached via click chemistry). Such probes can be added to cells for 1-24 hours, and uptake and localization are studied by confocal microscopy.
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| Animal Protocol |
The final conjugate, not the linker alone, is administered to animals. A typical in vivo protocol for an ADC built with this linker involves a murine xenograft model. Female athymic nude mice are injected subcutaneously with 5-10×10⁶ antigen-positive tumor cells. When tumors reach 100-200 mm3, mice are randomized into treatment groups (n=8-10). The ADC is formulated in PBS and administered intravenously (i.v.) via the tail vein at doses of 1-10 mg/kg (based on antibody content). Tumor volumes are measured with calipers every 2-3 days, and body weights are recorded. Treatment is typically administered once weekly for 2-4 weeks. At the end of the study, tumors are excised, weighed, and analyzed. For PROTACs, a typical in vivo protocol involves tumor xenografts of target-expressing cancer cells, with the PROTAC administered orally or intraperitoneally at doses of 10-100 mg/kg. The pharmacokinetics of the PROTAC and target protein degradation levels in the tumor are measured by Western blot.
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| ADME/Pharmacokinetics |
The pharmacokinetics (PK) of the final conjugate, not the linker alone, are measured. For ADCs built with this linker, the PK is characterized by the antibody. The PEG4 spacer increases hydrophilicity, which can reduce clearance and improve half-life slightly compared to non-PEGylated ADCs. The Boc group is removed prior to the final conjugation and is not present in the final product. The oxime bond formed after deprotection is stable under physiological conditions (pH 7.4), with t1/2 for hydrolysis of days to weeks (depending on the oxime structure). The triazole ring formed by CuAAC is also stable. For PROTACs, the PEG4 linker contributes to overall hydrophilicity, which can improve solubility and oral bioavailability. The volume of distribution (Vd) for a PROTAC is typically moderate, and clearance is often via hepatic metabolism.
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| Toxicity/Toxicokinetics |
The toxicity of the final conjugate, not the linker alone, is evaluated. For ADCs built with non-cleavable linkers, off-target toxicity is generally lower than for cleavable linkers due to reduced premature payload release. However, if the ADC is internalized by non-target cells via non-specific uptake, the payload will still be released after lysosomal degradation, potentially causing toxicity. The PEG4 spacer reduces aggregation, which can lower immunogenicity and non-specific uptake. For PROTACs, toxicity is dependent on the target protein and the off-target degradation profile. For laboratory handling of the linker, standard chemical safety precautions apply: use gloves, lab coat, eye protection. The Boc group is not hazardous. The compound is for research use only. Store at -20degC in a dry, dark environment. The Boc group is stable under basic and neutral conditions but labile under strong acidic conditions. Avoid exposure to strong acids.
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| References |
[1]. Beck A, et al. Strategies and challenges for the next generation of antibody-drug conjugates. Nat Rev Drug Discov. 2017 May;16(5):315-337.
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| Additional Infomation |
Boc-aminooxy-amide-PEG4-propargyl is a non-cleavable 4-unit polyethylene glycol (PEG) linker commonly used in the synthesis of antibody-drug conjugates (ADCs) and PROTACs. It is also a click chemistry reagent, containing an Alkyne group for CuAAC with azides. The Boc-protected aminooxy group allows for selective deprotection and oxime ligation, providing orthogonal conjugation strategies. The PEG4 spacer (4 ethylene glycol units) provides moderate water solubility and flexibility. The compound is commercially available from chemical suppliers for research use only. The Boc group is removed under standard acidic conditions (e.g., 50% TFA in DCM, 1 hour). After deprotection, the free aminooxy group can react with aldehydes or ketones at pH 4-6 to form stable oxime bonds. The alkyne group (propargyl) can react with azides via CuAAC or with strained alkynes via SPAAC if modified. This compound is a versatile building block for the modular construction of complex bioconjugates. It should be stored at -20degC in a dry environment protected from light.
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| Molecular Formula |
C18H32N2O8
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|---|---|
| Molecular Weight |
404.4553
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| Exact Mass |
404.215
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| CAS # |
2253965-01-2
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| PubChem CID |
146026151
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| Appearance |
Colorless to light yellow liquid（Density：1.125 g/cm3）
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| LogP |
-0.2
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| Hydrogen Bond Donor Count |
2
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| Hydrogen Bond Acceptor Count |
8
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| Rotatable Bond Count |
18
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| Heavy Atom Count |
28
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| Complexity |
470
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| Defined Atom Stereocenter Count |
0
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| SMILES |
CC(C)(C)OC(=O)NOCC(=O)NCCOCCOCCOCCOCC#C
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| InChi Key |
XDRDVAXJEVQKKC-UHFFFAOYSA-N
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| InChi Code |
InChI=1S/C18H32N2O8/c1-5-7-23-9-11-25-13-14-26-12-10-24-8-6-19-16(21)15-27-20-17(22)28-18(2,3)4/h1H,6-15H2,2-4H3,(H,19,21)(H,20,22)
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| Chemical Name |
tert-butyl N-[2-oxo-2-[2-[2-[2-(2-prop-2-ynoxyethoxy)ethoxy]ethoxy]ethylamino]ethoxy]carbamate
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| Synonyms |
BocaminooxyamidePEG4propargyl; Boc aminooxy amide PEG4 propargyl
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 2.4724 mL | 12.3622 mL | 24.7243 mL | |
| 5 mM | 0.4945 mL | 2.4724 mL | 4.9449 mL | |
| 10 mM | 0.2472 mL | 1.2362 mL | 2.4724 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
Products are for research use only; We do not sell to patients
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