Disciformycins A and B: 12-Membered Macrolide Glycoside Antibiotics from the Myxobacterium Pyxidicoccus fallax Active against Multiresistant Staphylococci

Two macrolide glycosides with a unique scaffold were isolated from cultures of the myxobacterium Pyxidicoccus fallax. Their structures, including absolute configurations, were elucidated by a combination of NMR, MS, degradation, and molecular modeling techniques. Analysis of the proposed biosynthetic gene cluster led to insights into the biosynthesis of the polyketide and confirmed the structure assignment. The more active compound, disciformycin B, potently inhibits methicillin‐ and vancomycin‐resistant Staphylococcus aureus. The myxobacterium­ Pyxidicoccus fallax was the source of two natural products with a unique scaffold, disciformycins, which exhibit promising and almost selective activity against multiresistant staphylococci. The more active compound, disciformycin B, shows strong inhibition even of methicillin‐ and vancomycin‐resistant isolates (see picture).