Chromogenic compounds, a process for their preparation, and their use

Abstract From the Canadian patent

Chromogenic compounds a process for their preparation, and their use Compounds of the formula I, (I), in which X denotes a hydrogen atom, a group which irreversibly masks the terminal amino group, or a protecting group which is conventional in peptide chemistry such as, for example, Boc-, Z- or Fmoc- A and B, may be identical or different and denote an alphabeta- or gamma-amino acid which comprises 2 to 15 carbon atoms and up to 4 nitrogen atoms 2 sulfur, atoms and 6 oxygen atoms and whose side chain may be substituted, and B, if appropriate, denotes a dipeptide formed from these amino acids, C denotes arginine lysine, tyrosine, phenylalanine or, tryptophane and their homologs, R1 and R2, …