Abstract Monoalkylation or acylation of fluorescein (1) with various acyloxymethyl or acyl halides afforded, respectively, a series of ether-(2) and ester-functionalized (3) fluorogenic probes. The highly reactive and water-soluble substrates release fluorescein (1) upon reaction with lipases and esterases within seconds or minutes, both under fully aqueous conditions or in the presence of DMSO (20%) as a co-solvent. The most-reactive ...
