Abstract: Guided by antibacterial assay,the chemical components of the fermentation products of strain SCSIO 81-F2,which was isolated from a sediment collected in the South China Sea,were isolated and purified using silica gel column chromatography and semi-preparative HPLC.Three known compounds,xanthocillin X-dimethylether (1), xanthocillin X monomethylether (2),6′,8′-dimethoxy xanthocillin X dimethylether (3) were obtained from the fermentation products.The structures of the purified compounds were identified based on MS and NMR spectroscopic analysis and X-ray crystallography.This fungus was identified as Aspergillus sp.SCSIO 81-F2 on the basis of phylogenetic tree analysis of its 18S rDNA sequence,which was a new source of producing xanthocillin X type compounds with antibacterial acitivity.

Key words: Xanthocillin X, marine fungus, Aspergillus, secondary metabolites