Novel anthelmintic metabolites from an Aspergillus species; the aspergillimides

Two members of a novel class of anthelmintics, the aspergillimides, have been isolated from the Aspergillus strain IMI 337664. This novel fungus also produced two known and one structurally novel paraherquamide. This paper describes the fermentation, isolation, structure elucidation and anthelmintic activity of aspergillimide (VM55598, 1), 16-keto aspergillimide (SB202327, 2), and the paraherquamides VM54159 (3), SB203105 (4) and SB200437 (5). The aspergillimides are equivalent to paraherquamides which have lost both the dioxygenated 7-membered ring and the phenyl ring to which this is fused; gaining in their place a C8-keto group. SB203105 is the first example of a 4-substituted paraherquamide.