The present invention relates to novel compounds of formulae (I) and (II) and pharmaceutically acceptable salts thereof that are useful in the treatment and/or prevention of human and animal bacterial infections and associated diseases and conditions; compositions containing such compounds; derivation of such compounds by fermentation and isolation, partial synthesis and total synthesis; methods of inhibiting bacterial growth; methods of treating, preventing or controlling bacterial infection; biologically pure cultures of bacterial strains from which such compounds may be produced; and processes for preparing compositions containing such compounds.