Isolation and identification of the nematicidal secondary metabolitesfrom one strain of entomogenous fungi

By application of different separation techniques,such as silica gel,Sephadex LH-20 column chromatography,and reversed-phase high performance liquid chromatography,two nematicidal secondary metabolites were isolated from the fermentation broth of one strain of entomogenous fungi Paecilomyces sp.The structures of these compounds were elucidated as Cerebroside A( 1 ) and Cerebroside B( 2 ) primarily by analysis of their NMR spectroscopic data.Bioassay tests showed that the two compounds had moderate nematicidal activities against Bursaphelenchus xylophilus,the average mortality of B.xylophilus caused by compound 1 at the mass concentrations of 1 000 ,100 and 10 μ g/mL were 100% ,100% and 11.1% ,respectively.