Thousands of halogenated natural products have been isolated from terrestrial organisms.These natural products include important antibiotics such as vancomycin,chloramphenicol and rebeccamycin.Marine microorganisms have been developed as a rich resource for novel compounds.including halogenated compounds because of the plentiful halogen environment.Haloperoxidases and flavin-dependent halogenases were thought to be involved in secondary metabolism of microorganisms.The majority of brominated compounds have been isolated from marine organisms.however mostly chlorinated compounds are produced by terrestral organisms.In our previous study,novel chlorinated antibiotics,chinikomycins,were isolated from the marine Streptomyces sp.M045.