Satisfactory separation and MS-MS spectrometry of six surfactins isolated from Bacillus subtilis natto.

We optimized HPLC conditions for the first time to achieve satisfactory separation of six surfactins, two of which were novel, isolated from Bacillus subtilis natto. Peptide sequences were analyzed by sophisticated MS-MS analysis, performed with a pair of two surfactins with different fatty acid substitutions. Fragment peaks were divided into two series; one was a series of the ions which carried fatty acid, and thus were characterized by the fatty acid mass difference, and the other was a series of the ions which consisted of pure peptide and thus showed a superimposable pattern between a pair of surfactins.