7449-51-6

Biological Activity: closed-HMRG is an HMRG (HY-D2379) with a closed spiro-ring structure. HMRG is a fluorescent dye, which serves as the fluorescent active product generated by enzyme-activated fluorescent probes targeting proteases and glycosidases. Its detection mechanism relies on the intramolecular spirocyclization equilibrium: HMRG itself exists in an open non-spirocyclic structure under physiological pH, which maintains a conjugated π system and produces strong fluorescence; whereas its probe precursors (such as Leu-HMRG, Ac-GlyPro-HMRG and βGal-HMRG) exist in a closed spirocyclic form and show no fluorescence due to the disruption of the π-conjugated system; when the target enzyme cleaves the substrate fragment linked to the probe precursor, the closed spirocyclic structure converts to the open structure of HMRG, restoring the conjugated system and generating a strong fluorescent signal. Its detection wavelength is Ex/Em = 501/524 nm^[1].