Directed biosynthesis of new enniatins

New cyclohexadepsipeptides of the enniatin type with potential anthelmintic properties were produced by two different strategies: 1. In vitro synthesi s by use of the multienzyme enniatin synthetase, and 2. in vivo precursor f eeding of enniatin producing strains Fusarium scirpi and Fusarium sambucinu m. The compounds were analyzed by HPLC, various NMR measurements and mass s pectrometry. The three N-methyl L-amino acid positions in the enniatin B mo lecule could be gradually replaced by other (N-methyl) L-amino acids, e.g. alanine, cysteine, threonine and serine. The latter two amino acids yield n ew enniatins with functional groups in the hydrophobic side chains. Similar ly the three D-2-hydroxyisovalerate residues, present in all naturally occu ring enniatins, could be substituted by D-2-hydroxybutyric acid and D-lacti c acid. Despite its lower yield the in vitro synthesis has the advantage of a broader variety of products formed.