Methyltetrazine-PEG4-acid

• CAT Number: I016549
• CAS Number: 1802907-91-0
• Molecular Formula: C20H28N4O7
• Molecular Weight: 436.46
• Purity: ≥95%
• Synonyms: 3-[2-[2-[2-[2-[4-(6-methyl-1,2,4,5-tetrazin-3-yl)phenoxy]ethoxy]ethoxy]ethoxy]ethoxy]propanoic acid
• InChI: InChI=1S/C20H28N4O7/c1-16-21-23-20(24-22-16)17-2-4-18(5-3-17)31-15-14-30-13-12-29-11-10-28-9-8-27-7-6-19(25)26/h2-5H,6-15H2,1H3,(H,25,26)
• InChIKey: LMFGOJBYDNENPR-UHFFFAOYSA-N
• SMILES: CC1=NN=C(N=N1)C2=CC=C(C=C2)OCCOCCOCCOCCOCCC(=O)O

Methyltetrazine-PEG4-acid(CAT: I016549) is a compact, bioorthogonal linker featuring a methyltetrazine reactive handle connected via a four-unit PEG spacer to a terminal carboxylic acid. The methyltetrazine enables rapid inverse-electron-demand Diels–Alder (IEDDA) conjugation with strained dienophiles (e.g., trans-cyclooctene), delivering fast, selective labeling under mild, catalyst-free conditions. PEG4 improves aqueous solubility, reduces steric hindrance, and imparts flexibility for efficient coupling, while the carboxylic acid provides a convenient attachment point for amide bond formation. Ideal for site-specific protein labeling, imaging probe synthesis, drug–linker construction, and in-cell or in-vivo bioconjugation workflows where speed and chemoselectivity are essential.