A fluorescence assay for 4′-(9-acridinylamino)methanesulfon-m-anisidide, a new antitumor agent

Abstract A sensitive fluorescent method is described for the detection of 4′-(9-acridinylamino)-methanesulfon- m -anisidide (AMSA) in serum. The assay is based on the alkaline hydrolysis of AMSA into 9(10 H )-acridone. While AMSA has negligible fluorescence, 9(10 H )-acridone fluoresces brilliantly (excitation 266 nm, emission 470 nm). The assay is shown to be linear from 0.01 to 1.0 μ m . In addition, the assay is shown to be useful, in conjunction with an ethyl acetate extraction, in distinguishing serum levels of parent AMSA from metabolized or protein-bound AMSA.