Abstract: During our search for new antibacterial agents from natural products,two new (1,2) and four known metabolites (3-6) of dithiolopyrrolone derivatives,were isolated from fermentation broth of an insect pathogenic enterobacterium, Xenorhabdus bovienii SN52.Their structures were identified on the basis of NMR and MS spectroscopic analyses and by comparison with those reported previously.Compounds 1-6 were tested antibacterial activities using 96-well microdilution broth assay,and the structure-activity relationships indicated that the antibacterial activities of dithiolopyrrolone derivatives are significant influenced by the variable substituents of side chain.

Key words: Xenorhabdus bovienii SN52, dithiolopyrrolone derivatives, structural elucidation, antibacterial activity, structure activity relationship