Pseudomonic acid derivatives from a marine bacterium

The spongeDarwinella rosacea was found to harbor a host of marine microorganisms. One of these bacteria was identified as a marineAlteromonas species. The organic extract of this bacterium was antimicrobial, and the activity was traced to two novel pseudomonic acid derivatives1 and7. The structures of these compounds were elucidated by interpretation of the spectral data and extensive use of 2-dimensional NMR techniques and NOE studies on the parent compounds and the acetate derivatives2 and8.