Tetrazine-Ph-NHS ester

• CAT Number: I016395
• CAS Number: 1616668-55-3
• Molecular Formula: C14H11N5O4
• Molecular Weight: 313.27
• Purity: ≥95%
• Synonyms: (2,5-dioxopyrrolidin-1-yl) 2-[4-(1,2,4,5-tetrazin-3-yl)phenyl]acetate
• InChI: InChI=1S/C14H11N5O4/c20-11-5-6-12(21)19(11)23-13(22)7-9-1-3-10(4-2-9)14-17-15-8-16-18-14/h1-4,8H,5-7H2
• InChIKey: ORWDYVDDJMYIQA-UHFFFAOYSA-N
• SMILES: C1CC(=O)N(C1=O)OC(=O)CC2=CC=C(C=C2)C3=NN=CN=N3

Tetrazine-Ph-NHS ester(CAT: I016395) is a heterobifunctional crosslinker designed for rapid and selective bioconjugation. It features a tetrazine moiety, which undergoes ultrafast inverse electron-demand Diels–Alder (IEDDA) reactions with strained alkenes or alkynes (such as trans-cyclooctene, TCO), enabling bioorthogonal labeling without metal catalysts. The NHS ester group reacts efficiently with primary amines on proteins, peptides, or other biomolecules, forming stable amide bonds. The phenyl (Ph) spacer enhances stability and provides structural rigidity, while maintaining good reactivity and compatibility in aqueous and biological systems. This reagent is widely used in click chemistry, antibody–drug conjugates, imaging probe development, and site-specific protein modification.