New metabolites from the marine-derived fungus Aspergillus fumigatus.

A new alkaloid, fumiquinazoline K (1), and a new nordammarane triterpenoid (2), together with three known diketopiperazines (3-5) and tryptoquivaline F (6) have been isolated from a marine strain of Aspergillus fumigatus KMM 4 631 associated with the soft coral Sinularia sp. Their structures were determined by HR-MS and 1D and 2D NMR. Compounds 3-5 exhibit weak cytotoxicity against cytoplasm non-specific esterase in Ehrlich carcinoma cells. Compound 3 also induces early apoptosis of the same cells in a non-toxic range of concentrations.