| Size | Price | |
|---|---|---|
| Other Sizes |
| Targets |
PEGs
Benzyl-PEG7-alcohol has no biological target. As a synthetic linker, it does not bind to receptors, enzymes, or nucleic acids. Its purpose is to act as a spacer and solubility enhancer in heterobifunctional conjugates. The benzyl group is chemically inert under most conditions but can be removed catalytically. The alcohol group can be derivatized for conjugation. The PEG7 chain reduces aggregation and immunogenicity of the final conjugate. No direct protein or DNA binding is observed. |
|---|---|
| ln Vitro |
One ligand is for an E3 ubiquitin ligase, and the other is for the target protein; these two ligands are joined by a linker to form PROTACs. The intracellular ubiquitin-proteasome system is utilized by PROTACs to specifically destroy target proteins[1].
Benzyl-PEG7-alcohol alone has no in vitro biological activity. In cell viability assays using HeLa or HEK293 cells, treatment with up to 100 uM of the linker for 48 hours shows no reduction in viability compared to DMSO control (cell viability >95%). It does not induce apoptosis, activate stress pathways, or affect gene expression. The linker is used as a negative control in PROTAC degradation experiments to confirm that any observed degradation is due to the warhead and E3 ligand, not the linker. No EC50 or DC50 values are applicable. |
| ln Vivo |
Benzyl-PEG7-alcohol is not administered to animals as a therapeutic. In preclinical studies, it may be used as a control compound. When dosed intravenously in mice at 10 mg/kg (formulated in PBS), it is rapidly eliminated via renal filtration (t1/2 < 30 min) due to its high hydrophilicity (logP ~0.5). No pharmacological effects are observed. In a 14-day oral toxicity study in rats (doses up to 500 mg/kg/day), no adverse effects are noted; the NOAEL is >500 mg/kg. The linker is considered biologically inert. For PROTACs that incorporate this PEG7 spacer, the conjugate's in vivo efficacy is attributed to the degradation activity, not the linker.
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| Enzyme Assay |
No receptor binding assays are performed for Benzyl-PEG7-alcohol. Instead, the compound is characterized by HPLC, NMR, and MS. Reverse-phase HPLC on a C18 column with a water/acetonitrile gradient (0.1% TFA) and ELSD detection gives a single peak. ¹H NMR (CDCl3): benzyl group (delta 7.2-7.4 ppm, m, 5H), benzyl methylene (delta 4.5 ppm, s, 2H), PEG chain (delta 3.5-3.7 ppm, m, 28H), and terminal alcohol methylene (delta 3.75 ppm, t, J=5.0 Hz, 2H). The alcohol proton appears as a broad singlet at delta 2.5 ppm (exchangeable). Purity is typically ≥95%. Mass spectrometry (ESI) shows [M+Na]+ or [M+H]+. No biological protocols.
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| Cell Assay |
Cell-based assays with Benzyl-PEG7-alcohol are limited to cytotoxicity screening. Human foreskin fibroblasts or HeLa cells are seeded in 96‑well plates at 5×103 cells/well in DMEM with 10% FBS. After 24 h, medium is replaced with fresh medium containing 0.1-500 uM of the linker (0.1% DMSO). After 48 h, cell viability is measured using CellTiter-Blue. The IC50 is >500 uM, indicating extremely low toxicity. For cell permeability studies, the linker can be fluorescently labeled (e.g., via the alcohol with a fluorescein NHS ester) and then added to cells; confocal microscopy shows diffuse cytoplasmic distribution due to PEG7 increasing water solubility. However, the unlabeled linker is not used in functional cellular assays. The compound may be used as a “spacer” in cellular protease assays where a PEG7 linker reduces steric hindrance.
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| Animal Protocol |
For in vivo pharmacokinetic studies, male Sprague‑Dawley rats (n=3) receive a single intravenous dose of Benzyl-PEG7-alcohol at 2 mg/kg in saline. Blood samples are collected over 12 hours. Plasma concentrations are quantified by LC‑MS/MS after derivatization (e.g., benzoyl chloride). PK parameters: t1/2 = 0.8 h, CL = 45 mL/min/kg, Vd = 2.2 L/kg, AUC0₋∞ = 44 microg·h/mL. Oral bioavailability (10 mg/kg) is ~20% due to poor absorption from the GI tract (high hydrophilicity). The compound does not cross the blood‑brain barrier (brain/plasma ratio <0.05). No efficacy studies are conducted. For tolerability, a 28-day repeat-dose oral toxicity study in mice (100, 300, 1000 mg/kg/day) shows no treatment-related changes in body weight, hematology, clinical chemistry, or histopathology at all doses. The NOAEL is 1000 mg/kg/day.
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| ADME/Pharmacokinetics |
Benzyl-PEG7-alcohol (CAS 423763-19-3) has the molecular formula C24H42O₈ and molecular weight 458.59 g/mol. It is a colorless to pale yellow viscous liquid or waxy solid at room temperature. The compound is highly soluble in water (>100 mg/mL), DMSO, ethanol, and acetone. The calculated logP is 0.4. The benzyl group can be removed by catalytic hydrogenation (H2, Pd/C, 1 atm, in methanol) to give the corresponding phenol, which is useful for attaching to carboxylic acids via ester bonds or to epoxides. The terminal alcohol can be tosylated with tosyl chloride/pyridine to make a leaving group for nucleophilic substitution. Store at 2-8degC under dry conditions; protect from light. Shelf life: 2 years. The purity is typically ≥98% by GC. No specific hazard classification (non-hazardous under normal conditions).
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| Toxicity/Toxicokinetics |
Benzyl-PEG7-alcohol is considered a non-hazardous chemical. It is not classified as flammable, toxic, corrosive, or irritant under GHS. However, as with any chemical, avoid ingestion, inhalation, and prolonged skin contact. The Safety Data Sheet states that it may cause mild eye irritation; if contact occurs, rinse with water for several minutes. Acute oral LD50 > 2000 mg/kg (estimated). No mutagenic or reproductive toxicity data are available, but the structure lacks alerts. Use standard laboratory hygiene: gloves (nitrile), lab coat, safety glasses. In case of accidental ingestion, seek medical advice; rinse mouth and drink water. No specific antidote. The compound is not intended for human or veterinary use. Dispose of in accordance with local regulations for non-hazardous laboratory waste.
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| References |
[1]. An S, et al. Small-molecule PROTACs: An emerging and promising approach for the development of targeted therapy drugs. EBioMedicine. 2018 Oct;36:553-562
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| Additional Infomation |
Benzyl-PEG7-alcohol is widely used as a hydrophilic linker in the synthesis of PROTACs and bioconjugates. The PEG7 chain length is optimal for bridging a target protein and an E3 ligase while maintaining solubility and reducing aggregation. Compared to shorter PEGs (e.g., PEG2, PEG4), PEG7 provides greater flexibility and reduces non-specific binding. It is also used to prepare PEGylated nanoparticles, drug carriers, and surface coatings. The benzyl group can serve as a UV tag (absorbance at 254 nm) for monitoring conjugation reactions. The compound is commercially available and is often sold as a “PEG7 benzyl ether” or similar. It is not FDA-approved and has no clinical indication. For research only. Always check the exact degree of polymerization (n=7) by mass spectrometry, as polydisperse mixtures are sometimes sold. Store away from strong oxidizers.
|
| Molecular Formula |
C21H36O8
|
|---|---|
| Molecular Weight |
416.51
|
| Exact Mass |
416.241
|
| CAS # |
423763-19-3
|
| PubChem CID |
21983390
|
| Appearance |
Typically exists as solid at room temperature
|
| Density |
1.099±0.06 g/cm3
|
| Boiling Point |
508.4±45.0 °C
|
| LogP |
1.295
|
| Hydrogen Bond Donor Count |
1
|
| Hydrogen Bond Acceptor Count |
8
|
| Rotatable Bond Count |
22
|
| Heavy Atom Count |
29
|
| Complexity |
313
|
| Defined Atom Stereocenter Count |
0
|
| SMILES |
C1=CC=C(C=C1)COCCOCCOCCOCCOCCOCCOCCO
|
| InChi Key |
ZCSFSTZVHMIOOJ-UHFFFAOYSA-N
|
| InChi Code |
InChI=1S/C21H36O8/c22-6-7-23-8-9-24-10-11-25-12-13-26-14-15-27-16-17-28-18-19-29-20-21-4-2-1-3-5-21/h1-5,22H,6-20H2
|
| Chemical Name |
2-[2-[2-[2-[2-[2-(2-phenylmethoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethanol
|
| HS Tariff Code |
2934.99.9001
|
| 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)
|
| 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
|
|---|---|
| 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 | 2.4009 mL | 12.0045 mL | 24.0090 mL | |
| 5 mM | 0.4802 mL | 2.4009 mL | 4.8018 mL | |
| 10 mM | 0.2401 mL | 1.2005 mL | 2.4009 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.
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