Roquefortine E, a diketopiperazine from an Australian isolate of Gymnoascus reessii.

The new isoprenylated diketopiperazine roquefortine E (6) has been isolated from an Australian soil isolate of the ascomycete Gymnoascus reessii. The known fungal metabolite roquefortine C (1) was also recovered as the major antibacterial principle, and all structures were assigned by detailed spectroscopic analysis.