Isolation and characterization of a new variant of surfactin, the [Val7]surfactin.

Reinvestigation of surfactin, a previously studied peptidolipid surfactant from Bacillus subtilis, by fast-atom-bombardment mass spectrometry and 1H-NMR spectroscopy, as well as by chemical methods, revealed the presence of a closely related second constituent. This new compound, [Val7]surfactin, differs from the known surfactin by the C-terminal amino acid residue which is valine instead of leucine.