Fungitoxic prenylisoflavanones isolated from Geoffroea decorticans extracts

QUIROGA, E. N.; SGARIGLIA, M. A.; SOBERÓN, J. R.; SAMPIETRO D.A.; VATUONE, M. A.

Tafi del Valle (Tucumán)

Congreso; XXIV Annual Scientific Meeting of Tucuman Biology Society; 2008

Tucuman Biology Society (publicado en Bio Cell 32 (2), A64, 2008)

Fungi are a major cause of spoilage of stored grains. Certain fungi belonging to the genus Aspergillus can produce mycotoxins. There is a pressing need to replace synthetic fungicides for natural antifungal compounds that can be used in the preservation of human and animal food. In this work we isolated and identified two prenylisoflavanones from Geoffroea decorticans alcoholic extracts. They can inhibit the growth in vitro of some Aspergillus strains isolated from farm animal feeds (A. flavus, A. parasitiens, A. nomius VSC23, and A. nomius 13137). Their biocide activity was determined by bioautography and radial growth inhibition assays. They were isolated by CC and TLC and identified by NMR as tethrahydroxy-methoxi-prenyl-iso-flavanones (2). MICs and MFCs of crude extract and isolated substances were determined and compared to those of a synthetic fungicide (Clotrimazole) and ascorbic and sorbic acids used as preservatives. From our results we can suggest that G. decorticans extracts and the isolated purified compounds could be used as biopesticides against Aspergillus species and also in food conservation.