title: A spectroscopic off-on probe for simple and sensitive detection of carboxylesterase activity and its application to cell imaging.
abstract: A new resorufin-based spectroscopic probe, 7-(p-acetoxyphenylmethyloxy)-3H-phenoxazin-3-one (1), has been developed for detecting carboxylesterase activity. The probe is designed by introducing p-acetoxyphenylmethyloxy as a bifunctional moiety to resorufin. The p-acetoxyphenylmethyloxy moiety not only quenches the spectroscopic signal of resorufin, but also serves as a recognition unit for carboxylesterase. As a result, the prepared latent spectroscopic probe 1 shows very low background signal, which is rather desired for achieving sensitive detection. The specific cleavage of the carboxylic ester bond by carboxylesterase induces the hydrolysis of the probe, resulting in the release of resorufin and thereby the recovery of both color and fluorescence signal. This behaviour leads to the development of a simple and sensitive fluorescent method for assaying carboxylesterase activity, with a detection limit of 8.6 × 10(-5) U mL(-1), which is much more sensitive than the existing fluorescence approaches. Moreover, experimental results showed that the probe 1 is cell membrane permeable, and its applicability has been demonstrated for monitoring carboxylesterase activity in HeLa cells.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Duan
authors.initials: D
authors.lastname: Feng
authors.forename: Wen
authors.initials: W
authors.lastname: Shi
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Li
authors.forename: Huimin
authors.initials: H
authors.lastname: Ma
mesh_terms: D000085:Acetates / Q000737:chemistry*; D043182:Carboxylesterase / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy; D015335:Molecular Probes; D010078:Oxazines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: C571709:7-(p-acetoxyphenylmethyloxy)-3H-phenoxazin-3-one; D000085:Acetates; D015335:Molecular Probes; D010078:Oxazines; D043182:Carboxylesterase