Abstract: In order to clarify the active substance basis of herbicidal fungus NBERC_49006,its secondary metabolites were studied.Seven compounds were isolated by large-scale fermentation,extraction,preparative HPLC and gel column chromatography.The structures were elucidated on the basis of spectral characteristics and identified as:trichothecin (1)，8-deoxy-trichothecin (2),engleromycenolic acid A(3),engleromycenolic acid B(4),rosololactone (5),rosenonolactone (6),2α-hydroxy-cis-communic acid (7).Among them,compounds 2,4 and 7 were isolated from the strain for the first time,and compound 7 was obtained from microorganism for the first time.The results of bioassay test showed that compounds 1 and 2 had obvious herbicidal activity against Arabidopsis thaliana with the LC₅₀ value of 9.30 and 28.98 μg/mL,respectively.The results of this study can provide a good basis for the discovery of lead compounds with herbicidal activities from fungal.

Key words: Trichothecium roseum, secondary metabolites, trichotecin, 8-deoxy-trichotecin, herbicidal activity