Neopyrrolomycins with broad spectrum antibacterial activity.

Three new antibiotics, neopyrrolomycins B (1), C (2), and D (3), with potent activity against Gram-positive pathogens were discovered. They exhibited MIC values < 1 mu g/mL versus a number of resistant strains. The compounds were obtained from the ethyl acetate extracts of a Streptomyces sp. after purification by column chromatography and RP-HPLC. Their structures were elucidated using X-ray crystallography (1) and NMR spectroscopy (2 and 3).