The Biosynthesis of Vancomycin-Type Glycopeptide Antibiotics-The Order of the Cyclization Steps

Linear and bicyclic glycopeptides occur as intermediates in the biosynthesis of the aglycon of glycopeptide antibiotics of the type shown. Considering the structures of these peptides and those of previously isolated analogues, the sequence of the three oxidative ring-closing steps can be deduced for type-I and type-II glycopeptide antibiotics. Thus, comprehensive insight into the assembly of the aglycon is achieved for the first time.