New metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. VIII. Isolation, structure determination and biological activities of minor metabolites structurally related to mycorrhizin A

Five new minor metabolites, papyracon D (6), 6-O-methylpapyracon B (9), 6-O-methylpapyracon C (10), lachnumfuran A (11) and lachnumlactone A (12a), together with the known chloromycorrhizinol A (4), have been isolated from extracts of the culture fluids of the ascomycete Lachnum papyraceum. The compounds, which structures were determined by spectroscopic methods, are structurally related to the nematicidal and Antibiotic mycorrhizin A (1), which also is produced by the fungus. The nematicidal, Antibiotic and cytotoxic activities of the new compounds are weaker compared to those of mycorrhizin A (1). Papyracon D (6) possesses the highest Antibiotic activities while lachnumlactone A (12a) is the most nematicidal and cytotoxic.