METABOLITES OF ERWINIA .9. PROFILING OF BASIC-AMINO-ACIDS AND POLYAMINES IN MICROBIAL CULTURE SUPERNATANTS BY ELECTROSPRAY MASS-SPECTROMETRY

As part of our efforts to investigate the biosynthesis of proferrioxam ines in Erwinia amylovora, it was of interest to develop a methodology with which a large number of basic amino acids, di- and polyamines, a nd C- and N-hydroxy derivatives thereof could be monitored simultaneou sly. Towards this end, the on-line coupling of electrospray mass spect rometry with ion chromatography or reversed-phase chromatography was e xplored, Tandem mass spectrometry was found to be an excellent method for obtaining relevant structural information on underivatized polyami nes and basic amino acid, including N-hydroxy derivatives. However, th e coupling of ion chromatography with electrospray mass spectrometry f or on-line extraction and separation of the underivatized compounds is hampered by compatibility problems. For most target compounds, on-lin e reversed-phase liquid chromatography/electrospray mass spectrometry was the method of choice but required derivatization and in this respe ct dansylation was preferred over benzoylation. Neither derivatization method is suitable for N-hydroxy compounds, which are base-sensitive.