BDP FL-PEG5-propargyl

BDP FL-PEG5-propargyl is a fluorescent conjugation reagent that combines a BDP FL fluorophore, a hydrophilic PEG5 spacer, and a terminal propargyl group. The PEG segment separates the dye from the conjugated component, while the terminal alkyne provides a defined site for copper-catalyzed click chemistry. This architecture is suitable for preparing fluorescently labeled ligands, probes, and linker-containing conjugates.

Structure: The molecule consists of a BDP FL fluorophore connected to a terminal propargyl group through a PEG5 spacer. Ether linkages within the PEG chain provide polarity and conformational flexibility, while the BDP FL core supplies the fluorescent reporter. The propargyl terminus is an unstrained terminal alkyne rather than a strained cyclooctyne.

Reactivity: The terminal propargyl group reacts with azide-functionalized partners through copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC), forming a stable triazole linkage. Suitable Cu(I) sources, copper-stabilizing ligands, and solvent systems should be selected according to the sensitivity and solubility of the conjugation partners. This terminal alkyne does not directly support strain-promoted azide–alkyne cycloaddition (SPAAC). If a copper-free workflow is required, a strained cyclooctyne reagent, such as a DBCO- or BCN-functionalized derivative, should be used instead.