Synthesis of novel fluorogenic edman reagents, 7‐N,N‐dimethylaminosulphonyl‐4‐(2,1,3‐benzoxadiazolyl)isothiocyanate (DBD‐NCS) and 7‐aminosulphonyl‐4‐(2,1,3‐benzoxadiazolyl)‐isothiocyanate (ABD‐NCS)

Abstract

Novel fluorogenic Edman reagents, 7‐N,N‐dimethylaminosulphonyl‐4‐(2,1,3‐benzoxadiazolyl)isothiocyanate (DBD‐NCS) and 7‐aminosulphonyl‐4‐(2,1,3‐benzoxadiazolyl)isothiocyanate (ABD‐NCS) having no fluorescence themselves were synthesized. The derivatives of amino acids with DBD‐NCS fluoresce at 505 nm with excitation at 385 nm. They were separated on a reversed‐phase HPLC column and detected at the sub‐picomol level. Ala‐Phe derivatized with DBD‐NCS was cleaved by acid to generate DBD‐thiocarbamyl‐Ala.