New Types of Liposidomycins Produced by Streptomyces that Inhibit Bacterial Peptidoglycan Synthesis Structure Elucidation of Fatty Acid Components by Tandem Mass Spectrometry

The structures of the fatty acid components of various new liposidomycins were determined using tandem mass Spectrometry; the negative FAB/MS/MS/MS technique for liposidomycins with a 3-methylglutaric acid moiety and the negative FAB/MS/MS technique for liposidomycins without a 3-methylglutaric acid moiey. This structural information was obtained by analysis of peaks due to charge-remote fragmentations for 3-hydroxycarboxylate anions or carboxylate anions which were generated from liposidomycin molecules in a mass spectrometer. The MS/MS/MS technique that can exclude the matrix-derived and/or interfering ions showed higher sensitivity than the MS/MS technique.