Abstract: The secondary metabolites of soil Streptomyces sp.KIB-K1 were investigated.Seven macrolides were isolated by the means of various chromatography methods,such as silica gel column,Sephadex LH-20 column and pre-HPLC,from the fermentation broth of Streptomyces sp. KIB-K1.Their structures were identified as aldgamycin E (2),aldgamycin J (3),aldgamycin K (4),aldgamycin L (5),GERI-155 (6),chalcomycin (7) and a new compound,aldgamycin P (1),by analyzing the NMR and Mass data.The result of antibacterial test showed that these macrolides exhibited significant inhibitory effect against Staphylococcus aureus ATCC 6538 and Bacillus subtilisATCC 6633.The minimal inhibit concentration (MIC) of aldgamycin P (1) to S.aureuswas 7.81 μg/mL.The MIC of compounds 2 and 7 to S. aureus were 0.49 and 0.98 μg/mL,respectively,which was higher than that of positive control kanamycin with MIC of 3.91 μg/mL.However,compounds 1-7 showed no inhibitory effect against two pathomycetes of plant,Gibberella zeae and Helminthosporium maydis Nisik & Miy.

Key words: Streptomyces, secondary metabolites, macrolides, antibacterial activities, aldgamycin P