Submitted to: Journal of Natural Products
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/28/2006
Publication Date: 4/2/2006
Citation: Jayasinghe, L., Abbas, H.K., Jacob, M., Hearth, W., Nanayakkara, D. 2006. New n-methyl-4-htydroxy-2-pyridinone analogs from fusarium oxysporum. Journal of Natural Products. Vol. 69: 439-442. Interpretive Summary: Some fungi (molds) can cause serious diseases in human, animals, and crops. In many cases agents available to treat these diseases are of limited utility. At the same time, molds can be very useful sources of antibiotics and drugs to cure these diseases for human, animals, and plants. An extract was made from the mold called Fusarium oxysporum that is a plant pathogen. Five active antibiotics were found in the extract, three of which are new. Two of the new compounds were active against the mold called Aspergillus fumigatus which causes disease in humans. The third, wortmannin, was active against the yeast that causes thrush and vaginal infections in humans. These new compounds did not show activity against molds that cause problems in agriculture. This information is valuable to scientists searching for potential treatments for humans, crops, and animal diseases.
Technical Abstract: Bioassay-guided fractionation of the ethyl acetate extract of Fusarium oxysporum (N17B) resulted in the isolation and identification of three new N-methyl-4-hydroxy-2-pyridinone analogs, 6-epi-oxysporidinone (3), dimethyl ketal of oxysporidinone (4), and N-demethylsambutoxin (5), along with the known compounds, (-)-oxysporidinone (1), (-)-sambutoxin (2), and wortmannin. Oxysporidinone has previously been isolated from a different strain of F. oxysporum but optical rotation reported for this compound was dextrorotatory. Compounds 1 and 3 showed selective fungistatic activity against the human pathogen, Aspergillus fumigatus, and wortmannin showed selective potent activity against Candida albicans. Compounds 1-5 were also evaluated for their activity against agriculturally the important fungi Fusarium verticillioides (syn. F. moniliforme) and Aspergillus flavus. These compounds had no activity against these fungi up to concentrations of 10 mg/mL.