We have developed new fluorescent amino acids which were easily synthesized by condensation of the fluorescent molecule and protected amino acids, which were ornithine and serine. Fluorescent molecule was prepared from oxalacetic acid diethyl ester and N,N-dimethylphenylenediamine by 3 steps. Protected amino acids were prepared by 2 and 5 steps from commercially available ornithine and serine derivatives, respectively. With the increase of solvent polarity, the emission spectra of both fluorescent amino acids clearly shifted from 430 nm to 500 nm. Both of Fmoc-protected fluorescent amino acids could be converted to fluorescent peptides by solid-phase synthesis.
