Reassignment of the Structure of the Antibiotic A53868 Reveals an Unusual Amino Dehydrophosphonic Acid

摘要

Antibiotic biosynthesis has enjoyed a renewed interest in recent years, with most efforts directed at polyketide synthases, non-ribosomal peptide synthetases, and antimicrobial peptides. Relatively unexplored with respect to biosyn-thetic pathways are phosphonate antibiotics, despite their commercial use as pharmaceuticals, herbicides, and pesticides. In fact, currently the biosynthetic pathways of only three phosphonate antibiotics are known: fosfomycin, bialaphos, and FR900098. These studies and others have uncovered intriguing new biochemical transformations involved in phosphonate biosynthesis. As part of a program to provide more insights into the biogenesis of this class of compounds, we investigated A53868, the structure of which was originally reported as 1 but later revised to 2 (Scheme l).