Abstract: The secondary metabolites of Streptomyces sp.KIB-H1556 that an actinomycetes isolated from the rhizosphere soil of Datura stramonium L.were investigated.The extracts were purified by silica gel column,Sephadex LH-20 chromatography and semi-preparative HPLC.The structures of compounds were elucidated by NMR and mass spectrometry,and comparison with the reported data.Three compounds were identified as Bafilomycin D (1),Bafilomycin B1 (2) and Bafilomycin B2 (3).The antifungal assays demonstrated that compounds 2 and 3 possessed broad-spectrum antifungal activities against pathogenic fungi,especially pathogenic fungi related to corn.This result suggests that bafilomycins can been developed as potential antifungal agent for corn.

Key words: Streptomyces, secondary metabolites, macrolides, antifungal activity