Mal-PEG4-NHS ester， Maleoyl-PEG4-N-hydroxysuccinimide ester

• Mal (maleoyl): capable of selective covalent reaction with thiol (- SH) groups;

• PEG4 (Polyethylene Glycol 4 Unit): Provides water solubility and molecular flexibility;

• NHS ester (N-hydroxysuccinimide ester): can covalently bond with amino (- NH2) groups.

Overview of synthetic routes

The synthesis of Mal-PEG4-NHS ester typically involves the following steps:

1. Functionalization of PEG4 chains

• Starting from PEG4 (HO-PEG4-OH) at the hydroxyl end, functionalization of the other end is ensured by selectively protecting one end (such as methoxy or tert butyl protection).

• Introducing carboxyl groups (- COOH) into the unprotected end is usually achieved through esterification or oxidation reactions.

2. Carboxyl activation

• By the interaction between NHS and DCC or EDC, PEG4 carboxyl groups are converted into activated esters to obtain PEG4-NHS.

• Activated esters have high reactivity and can be used for coupling with amino groups or other nucleophilic reagents.

3. Introduction of Maleoyl Group

• Coupling PEG4-NHS with maleimide derivatives is usually done in dry organic solvents such as DMF or DMSO.

• After the reaction, the maleoyl group successfully connected to the end of the PEG4 chain, forming the Mal-PEG4-NHS ester.

4. Purification and characterization

• Use column chromatography or dialysis to remove unreacted PEG and by-products.

• Confirm the structure and purity through nuclear magnetic resonance (^ 1H-NMR), mass spectrometry (MS), and high performance liquid chromatography (HPLC).

Purity: 95%+

Characteristic: Solid or liquid

Storage conditions: Dry at -20 ° C and stored away from light

Packaging specifications: 50mg 100mg 250mg 500mg (provided upon request)

Manufacturer: Qiyue Biotechnology

About Us

Qiyue Biotechnology provides customized services for near-infrared fluorescent cyanine dye labeling of various functional groups, such as active esters (NHS esters), maleimide (MAL), azide (N3), alkyne, etc., which facilitate covalent coupling with proteins, peptides, polysaccharides, antibodies, oligonucleotides, nanoparticles, etc. Multiple functional groups can be selected to precisely bind with target molecules, achieving fluorescent modification of proteins, peptides, antibodies, nucleic acids, or nanomaterials. In addition, Qiyue Biotechnology also provides customized dye labeling services, including peptides, proteins, small molecules, sugars and other types of markers, to meet users' personalized applications in scientific research, imaging and other fields.

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For scientific research only, cannot be used for human experiments AXC.2025.09