ARS | Publication request: FUNGICIDAL ACTIVITY OF NATURAL AND SYNTHETIC SESQUITERPENE LACTONE ANALOGS

Submitted to: Phytochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 5, 1999
Publication Date: N/A

Interpretive Summary: The antifungal activity of 36 natural product-based derivatives was studied. The five most active compounds were evaluated as potential natural alternatives to commercial synthetic fungicides. Growth of several important fungal plant pathogens was inhibited. Information about chemical and molecular characteristics that affect biological activity is also discussed. Two compounds demonstrated effective antifungal activity against the fungal pathogens which cause strawberry anthracnose that have become resistant to synthetic fungicides.

Technical Abstract: Fungicidal activity of 36 natural and synthetic sesquiterpene lactones with guaianolide, trans, trans-germacranolide, cis, cis-germacranolide, melampolide, and eudesmanolide carbon skeletons was evaluated against the phytopathogenic fungi Colletotrichum acutatum, C. fragariae, C. gloeosporioides, Fusarium oxysporum, Botrytis cinerea, and Phomopsis sp. Dose-response data for the active compounds dehydrozaluzanin C, dehydrocostuslactone, 5a-hydroxydehydrocostuslacone, costunolide, and zaluzanin C are presented. A new 96-well microbioassay procedure for fast and easy evaluation of antifungal activity was used to compare these compounds with commercial fungicide standards. Some structure-activity conclusions are also presented.