Design, synthesis and evaluation of novel P450 fluorescent probes bearing α-cyanoether

Four α-cyano-containing ethers based on 2-alkoxy-2-naphthylacetonitriles have been designed as a novel structural class of cytochrome P450 fluorescent probes. Their syntheses, fluorescence properties and evaluation in the fluorogenic assay of cytochrome P450 monooxygenase are reported. After P450 enzymatic O-dealkylation, the cyanohydrin metabolite of the four new substrates rearranges to a fluorescent aromatic aldehyde with a larger Stokes shift, and the new substrates exhibit higher specific activities than that of the commercial substrate 7-ethoxyresorufin (ER).