Mal-PEG4-OH

• CAT Number: I016238
• CAS Number: 1421933-37-0
• Molecular Formula: C12H19NO6
• Molecular Weight: 273.28
• Purity: ≥95%
• Synonyms: 1-[2-[2-[2-(2-hydroxyethoxy)ethoxy]ethoxy]ethyl]pyrrole-2,5-dione
• InChI: InChI=1S/C12H19NO6/c14-4-6-18-8-10-19-9-7-17-5-3-13-11(15)1-2-12(13)16/h1-2,14H,3-10H2
• InChIKey: DAQPEIZPEVDMSB-UHFFFAOYSA-N
• SMILES: C1=CC(=O)N(C1=O)CCOCCOCCOCCO

Mal-PEG4-OH(CAT: I016238) is a heterobifunctional polyethylene glycol (PEG) linker containing a maleimide moiety and a terminal hydroxyl group separated by a four-unit PEG spacer. The maleimide group enables site-specific conjugation with thiols, allowing efficient labeling of cysteine residues in peptides, proteins, or antibodies. The terminal hydroxyl can be further derivatized into esters, ethers, or activated intermediates for expanded bioconjugation strategies. The PEG4 spacer improves solubility, flexibility, and biocompatibility, while reducing steric hindrance during coupling. Mal-PEG4-OH is highly valuable for the preparation of inhibitors, antibody–drug conjugates, and targeted probes in cancer, immunology, and metabolic disease research requiring stable and precise conjugation.