Submitted to: Tetrahedron Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/1998
Publication Date: N/A
Interpretive Summary: Fungi that parasitize and kill other fungi offer a potential source of novel antifungal agents useful to agriculture and medicine. Chaetomium brasiliense, encountered as a colonist of Aspergillus flavus sclerotia (survival structures) in corn fields, was examined for its ability to produce antifungal agents and other bioactive metabolites. Chaetochalasin A is reported as a new bioactive fungal metabolite with an unprecedented ring system. This metabolite displayed cytotoxicity in the National Cancer Institute's 60-cell line human tumor panel and antibacterial activity in standard disk assays against Bacillus subtilis and Staphylococcus aureus. The potent antifungal and antiinsectan activities associated with initial extracts of C. brasiliense were accounted for by known chaetoglobosin metabolites.
Technical Abstract: Chaetochalasin A, a new bioactive fungal metabolite with a previously undescribed ring system, has been isolated from an EtOAc extract of Chaetomium brasiliense (NRRL 22999). The structure of Chaetochalasin A was determined by NMR experiments and single-crystal X-ray diffraction analysis.