Résumé
Objective: To study the chemical structure and activity of secondary metabolites of the endophytic fungus Bipolaris sorokiniana A606 isolated from Pogostemon cablin. Methods: The compounds were isolated and purified from the ethyle acetate extract of the fungal fermentation broth by silica gel, reverse phase silica gel, Sephadex-LH20, HPLC, and so on. Their structures were identified by extensive spectroscopic analysis. The compounds were evaluated for their cytotoxic activities against human tumor cell lines by the SRB assay and their antibacterial activities against bacteria were evaluated by the filter paper method. Results: Two compounds were isolated from the fermentation broth extract of the strain A606 and identified as (3S*,4aS*,6aS*,12bS*)-3-(2-hydroxypropan-2-yl)-6a,12b-dimethyl-9-[(2R*,4R*)-4-methyl-3-oxohexan-2-yl]-1,2,3,4a,5,6-hexahydropyrano [3,2-a]xanthene-8,11-dione (1) and precochlioquinol D (2). Conclusion: Compound 1 is a new compound, named 11-hydroxy-12,13-dehydrocochlioquinone B. Compound 2 is isolated from the species of genus Bipolaris for the first time. Compound 1 shows the cytotoxic and antibacterial activities.