Chemical. CAS 87687-02-3. Formula C19H13NO3. MW 303.31. Resorufin benzyl ether 7-Benzyloxyresorufin is a fluorogenic substrate widely used for monitoring cytochrome P450 CYP450 activities in cell extracts and solutions. It is the model substrate for 7-Benzoxyresorufin-O-dealkylase BROD assays. It is typically used near its apparent Km value of 30 �M to screen the inhibition/activation potential of test compounds, to predict potential drug-drug interactions, or to monitor other CYP450 activities. Cytochrome P450 oxidase is a large number of evolutionary related oxidative enzymes important in animal, plant, and bacterial physiology. Most cytochromes P450 CYPs have about 500 amino acids and a heme group at the active site. Upon enzymatic cleavage of 7-Benzyloxyresorufin by CYP450, the fluorescent hydrolysis product resorufin is released and its fluorescence can be used to quantify enzyme activity. Spectral data of Resorufin lambdaex=571nm, lambdaem=585nm.