Photodiode array detection of peptide-nucleoside antibiotics.

The discrimination within fermentation matrices of some structurally related peptide-nucleosides is vastly simplified by coupling photodiode array detection to high-performance liquid chromatography (HPLC). Blasticidin S analogues and other closely related nucleosides can easily be discriminated with on-line photodiode array spectral acquisition (PDA). From the combined HPLC-PDA evaluation of the fermentation filtrate from culture broth 83-2245, two blasticidin S type compounds, Sch 36605 and Sch 36606 could be detected. Mildiomycin, a structurally related nucleoside produced from ATCC culture 31120, could be detected during preliminary isolation without an authentic reference for comparison. Fast atom bombardment mass spectroscopic evaluations and mass-analysed ion kinetic energy spectra of these nucleosides confirmed their respective identities.