Fluorescent oxidation products derived from DBD-thiocarbamoyl amino acid in the modified Edman sequencing analysis.

The fluorescent product obtained by the oxidation of 7-N, N-dimethylaminosulfonyl-4-(2,1,3-benzoxadiazolyl) (DBD)-thiocarbamoyl (TC)-proline with NaNO(2)/H(+) in the modified Edman sequencing procedure was identified as the corresponding thiazolyl compound, N-[(8-dimethylaminosulfonyl)thiazolo[5,4, e]benzo[2,1,3]oxadiazol-5-yl]-L-proline, formed by the attack of the sulfur atom of the thiocarbamoyl group on the benzofurazan skeleton. The reaction mechanism for the formation of the fluorescent compound from DBD-TC primary and secondary amines is also discussed.