ANALYTICAL CHARACTERIZATION OF PEPTIDE CONTAMINANTS OF L-TRYPTOPHAN

Reversed-phase liquid chromatographic fractions of extracts of 2 prepa rations of eosinophilia-myalgia syndrome (EMS)-associated L-tryptophan were analyzed by proton nuclear magnetic resonance spectrometry, mass spectrometry, microbial-growth inhibition, and amino acid residue ana lyses. Fraction components demonstrated properties of an antibiotic pe ptide resembling bacitracin. Many peptide antibiotics like bacitracin are secondary metabolites of Bacillus species, genus of the tryptophan producer organism for the implicated manufacturer. In order to determ ine whether a correlation exists between individual EMS cases and the concentration of peptides or bacitracin consumed, reliable methods mus t be developed for quantification of the total of isoforms.