2007 Annual Report
Use of Safe Natural Compounds to Enhance Antifungal Activity of Commercial Fungicides and Antifungal Drugs. Fungal infection of crop plants poses a major problem to agricultural productivity, quality of agricultural products and food safety resulting from toxins that certain fungi produce. Additonally, there a certain fungi that are significant human pathogens, whose infection can lead to serious debilitation or death. USDA scientists in the Plant Mycotoxin Research Unit, Albany, CA have identified a number of safe, natural products that can significantly enhance the effectiveness of commercial fungicides, such as strobilurin and fludioxonil. These natural compounds are used to weaken the ability of the fungi to build their cell walls or to respire normally. Once these fungi are weakened by this “chemo-sensitization” the commercial products are anywhere from 100 to 1000 fold more effective. In collaboration with scientists at the MD Anderson Cancer Center, University of Texas and the Institute of Hygiene and Tropical Medicine, Lisbon, Portugal, this process of chemo-sensitization was also found to be effective against a number of human pathogenic fungi, as well. In this case, a number of natural compounds were found that enabled the use of antifungal drugs, such as itraconazole or fluconazole, against strains that had become resistant to these drugs. The use of this chemo-sensitization has promising potential in agriculture and medicine to help reduce environmental impact and costs of using fungicides and preventing or overcoming resistance. Accomplishment falls under National Program 108 (Food Safety), Component, 2.1.4.
Discovery of Analogs of Ferulic Acid as Potent Antifungal Agents. Fungal infections of agricultural products has a major impact on production, food quality and safety. Use of commercial fungicides is expensive and has an impact on the environment. Moreover, fungal pathogens are continuously developing resistance to commercial fungicides. USDA Scientists in the Plant Mycotoxin Research Unit, Albany, CA, have found a number of chemical compounds related to the natural compound, ferulic acid, have significant fungicidal activity. Some of these compounds show commercial promise and the structures of the compounds help us to understand how they work against the fungus. Accomplishment falls under National Program 108 (Food Safety), Component, 2.1.4.
Natural Compounds Inhibit Production of the Fungal Toxin, Ochratoxin A. Ochratoxin A is a chemical made by a number of different fungi that can infect agricultural commodities such as, barley, grapes, coffee, dried fruit and nuts. It is carcinogenic and can damage the kidneys. As such, contamination by this toxin is a food safety issue, nationally and internationally. USDA scientists in the Plant Mycotoxin Research Unit, Albany, CA have identified a number of safe, natural compounds that prevent ochratoxin production. Augmentation of these compounds in food crops, through breeding, may help to lower or prevent ochratoxin contamination, improving the quality and safety of the product. Accomplishment falls under National Program 108 (Food Safety), Component, 2.1.4.
Molyneux, R.J., Schieberle, P. 2007. Compound Identification: A journal of Agricultural and Food Chemistry Perspective. Journal of Agricultural and Food Chemistry. 55(12):4625-4629.
Lardner, R., Mahoney, N.E., Zanker, T., Molyneux, R.J., Scott, E. 2006. Secondary metabolite production by the fungal pathogen eutypa lata: analysis of extracts from grapevine cultures and detection of those metabolites in planta. Australian Journal of Grape and Wine Research. 12(2):107-114.
Yu, J., Cleveland, T.E., Wilkinson, J.R., Campbell, B.C., Kim, J.H., Kim, H.S., Bhatnagar, D., Payne, G.A., Nierman, W.C. 2006. Aspergillus flavus expressed sequence tags and microarray as tools in understanding aflatoxin biosynthesis. Mycotoxin Research. 22(1):16-21.
Lee, S., Campbell, B.C., Ok, Y., Kim, J., Park, B., Liu, N. 2005. Biochemical changes in dehydrogenase, hydroxylase and tyrosinase of a permethrin-resistant strain of housefly larvae, musca domestica l. Environmental Toxicology and Pharmacology.20(2):258-263.
Kim, J.H., Campbell, B.C., Mahoney, N.E., Chan, K.L., Molyneux, R.J., May, G.S. 2007. Enhancement of fludioxonil fungicidal activity by disrupting cellular glutathione homeostasis with 2,5-dihydroxybenzoic acid. Federation of European Microbiological Societies Microbiology Letters. 270(2):284290.
Beck, J.J., Chou, S. 2007. The Structural Diversity of Phthalides from the Apiaceae. Journal of Natural Products. 70(5):891-900.
Beck, J.J., Kim, J.H., Campbell, B.C., Chou, S. 2007. Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogs. Journal of Natural Products. 70(5):779-782.
Kim, J.H., Campbell, B.C., Mahoney, N.E., Chan, K.L., Molyneux, R.J., May, G.S. 2007. Enhanced activity of strobilurin and fludioxonil by using berberine and phenolic compounds to target fungal antioxidative stress response. Letters in Applied Microbiology. 55:134-141.