Two new chlorinated diphenyl ethers (5, 6) have been isolated from the culture broth of an Aspergillus species obtained from leaf litter, together with the known benzophenone sulochrin (1), the grisandiene geodin (2), and the diphenyl ether asterric acid (3). The structure of another metabolite, methyl asterrate (4), was confirmed by single-crystal X-ray structure analysis.

Aims: To evaluate the relationship between leucinostatin production by Paecilomyces lilacinus isolates and their biological activities. Methods and Results: The nematicidal, parasitic and enzymatic activity of Australian P. lilacinus isolates were investigated. Nematicidal activities of culture filtrates were measured by mortality and inhibition of reproduction of Caenorhabditis elegans, whereas egg-parasitic activity was measured by colonization on Meloidogyne javanica. Enzymatic activities (protease and chitinase) were assayed on solid media. The results suggest that leucinostatins in P. lilacinus are indicators of nematicidal activity, whereas chitinase activity might be related to parasitism. Conclusions: Nematicidal activity of culture filtrates of Paecilomyces lilacinus strains related to their ability to produce leucinostatins. Significance and Impact of the Study: This is the first study describing the leucinostatins as nematicides.

A metabolite isolated from the culture filtrate of an isolate of the fungus Byssochlamys nivea has been shown to be the macrodiolide pyrenophorol, by an X-ray crystallographic study. The identity of pyrenophorol and helmidiol, a metabolite with anthelmintic activity, is established.

Two related butenolides have been isolated from a culture broth of a strain of the fungus, Acremonium sp. Although the lactone acid (3) is a known compound, the structure of the lactone diacid (4), deduced by spectroscopic analysis, is assigned for the first time. This compound appears to be identical to a partly characterised metabolite isolated, along with 3, from Chaetomium indicum in 1953.

A strain of a Byssochlamys nivea, isolated from saline mud in Western Australia as a part of statewide survey of soil fungi for nematophagous activity, was evaluated for its effect on nematodes. Culture filtrate of the fungus grown on potato dextrose broth for 7 days caused structural changes in the cuticle, aggregation of individuals, and mortality of Caenorhabditis elegans. In addition, the culture filtrate completely inhibited hatching of C. elegans eggs. Exudates from agar colonies also caused cuticular disruption and mortality of C. elegans. The cuticular disruption observed, not reported in nematodes before, was initiated in the labial region and spread towards the posterior region of the nematode within 10 min of application. This reaction occurred only in live nematodes. Cuticular disruption and mortality caused by the culture filtrate varied according to growth conditions. The active compound(s) in the culture filtrate were thermostable (100°C for 1 h); however freezing the culture filtrate (-20°C for 2 days) eliminated the activities, as did dialysis (<14 000 molecular weight). Cuticular disruption and mortality were also observed when the nematode was exposed to culture filtrates of two other strains of B. nivea supplied by CBS, The Netherlands. The culture filtrate also inhibited in vitro growth of the plant-pathogenic fungi Fusarium oxysporum, Gaeumannomyces graminis var. tritici, Phytophthora cinnamomi, Pythium irregulare and Rhizoctonia solani.