Brenda Bertinetti, Mercedes Scandiani, Gabriela Cabrera

Abstract: Based on the precedent discovery of a weak antifungal indole isolated from Aporpium caryae, which increased its activity when changing the N-alkyl chain, nineteen N-alkyl indoles, with alkyl chains from one to ten carbons and one or two hydroxyls, one amine or bromine functional groups, were prepared and fully characterized by spectroscopic methods. The aim of this study is the search for new synthetic agrochemical leads derived from natural products. The antifungal activity of the synthesized compounds against three fungal strains was measured in vitro. Six compounds presented good activity against Fusarium virguliforme, the causal agent of sudden-death syndrome (SDS) in soybean, in a bioautography assay. Four of them were tested in a germination test and in a greenhouse experiment. All tested compounds, applied as seed treatment, showed antifungal properties being effective to control SDS when there was low level of fungal contamination. Results indicate that some of the tested compounds are acting as growth inhibitors and represent new leads for the treatment of SDS for which no specific treatment has been previously reported.

Keywords: N-Alkyl Indole, Soybean Phytopathogen, Fusarium Virguliforme, Sudden-Death Syndrome

Cite this paper: nullB. Bertinetti, M. Scandiani and G. Cabrera, "Analogs of Antifungal Indoles Isolated from Aporpium Caryae with Activity Against Sudden-Death Syndrome of Soybean," American Journal of Plant Sciences, Vol. 2 No. 2, 2011, pp. 245-254. doi: 10.4236/ajps.2011.22026.

References

[1]   A. Takayuki, K. O’Donnell, M. M. Scandiani, “Sudden- death syndrome of soybean in South America is caused by four species of Fusarium: Fusarium brasiliense sp. nov., F. cuneirostrum sp. nov., F. tucumaniae, and F. virguliforme,” Mycoscience, Vol. 46, No. 3, 2005, pp. 162-183.

[2]   M. Bj?rling-Poulsen, H. R. Andersen, P. Grandjean, “Potential developmental neurotoxicity of pesticides used in Europe,” Environ. Health, Vol. 7, No. 1, 2008, pp. 1-22.

[3]   E. Hodgson, R. Rose, “Metabolic interactions of agrochemicals in humans,” Pest Manag. Sci. Vol. 64, No. 6, 2008, pp. 617-621.

[4]   M. F. Simoniello, E. C. Kleinsorge, J. A. Scagnetti, R. A: Grigolato, G. L. Poletta, M. A. Carballo, “DNA damage in workers occupationally exposed to pesticide mixtures,” J. Appl. Toxicol. Vol. 28, No., 2008, pp. 957-965.

[5]   Y. Tanaka, “Antifungal agents,” In: S. Omura, Ed., The Search for Bioactive Compounds from Microorganisms, Springer-Verlag Inc., New York, 1992, pp. 31-44.

[6]   D. M. Gibson, S. B. Krasnoff, “Exploring the potential of biologically active compounds from plants and fungi,” In: H. G. Cutler, S. J. Cutler, Eds., Biologically Active Natural Products: Agrochemicals, CRC Press, Boca Raton, 1999, pp. 231-242.

[7]   H. L. Ypema, R. E. Gold, “Kresoxim-methyl, modification of a naturally occurring compound to produce a new fungicide,” Plant Dis. Vol. 83, No. 1, 1999, pp. 4-19.

[8]   L. M. Levy, G. M. Cabrera, J. E. Wright, A. M. Seldes, “Indole alkaloids from the culture of the fungus Aporpium caryae,” Phytochem. Vol. 54, No. 8, 2000, pp. 941-943.

[9]   F. Hadacek, H. Greger, “Testing of Antifungal Natural Products: Methodologies, Comparability of Results and Assay Choice,” Phytochem. Anal. Vol. 11, No. 3, 2000, pp. 137-147.

[10]   A. L. Homans, A. Fuchs, “Direct bioautography on thin- layer chromatography as a method for detecting fungitoxic substances,” J. Chromatog. Vol. 51, No. 2, 1970, pp. 325-328.

[11]   D. Sharma-Poudyal, E. Duveiller, R. C. Sharma, “Effects of seed treatment and foliar fungicides on Helminthosporium leaf blight and on the performance of wheat in warmer growing conditions,” J. Phytopathol. Vol. 153, No. 7-8, 2005, pp. 401-408.

[12]   C. Leach, 1963. “The qualitative and quantitative relationship of monochromatic radiation o sexual and asexual reproduction of Pleospora herbarum,” Mycologia, Vol. 55, No. 2, 1963, pp. 151-163.

[13]   M. M. Scandiani, A. G. Luque, “Identificación de Patógenos en Semilla de Soja,” In: G. Rolando, Ed., Suplemento Especial N 2, Análisis de Semillas, Estudio Rolando, Rosario, Argentina, 2009, pp. 1-148.

[14]   Y. H. Huang, G. L. Hartman, “Reaction of selected soybean genotypes to isolates of Fusarium solani f. sp. glycines and their culture filtrates,” Plant Dis. Vol. 82, No. 9, 1998, pp. 999-1002.

[15]   K. Karabelas, M. Lepisto, P. Sjo, “Preparation of new triazoles as pharmaceutically active compounds activity as kinase inhibitors,” Appl. US 2000; 646972.

[16]   M. Ishikura, W. Ida, K. Yanada, “A one-pot access to cycloalkano [1,2-a]indoles through an intramolecular alkyl migration reaction in indolylborates,” Tetrahedron, Vol. 62, No. 5, 2006, pp. 1015-1024.

[17]   F. Ziegler, L. O. Jeroncic, “A new route to 9,9a-dihydro- 3H-pyrrolo[1,2-a]indoles via radical cyclization,” J. Org. Chem. Vol. 56, No. 42, 1991, pp. 3479-86.

[18]   Q. Yue, C. J. Miller, J. F. White, M. Richardson, “Isolation and characterization of fungal inhibitors from Epichlo? festucae,” J. Agric. Food Chem. Vol. 48, No. 10, 2000, pp. 4687-4692.

[19]   M. Himejima, I. Kubo, “Fungicidal activity of polygodial in combination with anethole and indole against Candida albicans,” J. Agric. Food Chem. Vol. 41, No. 10, 1993, pp. 1776-1779.

[20]   B. Prapagdee, K. Kotchadat, A. Kumsopa, N. Visarathanonth, “The role of chitosan in protection of soybean from sudden death syndrome caused by Fusarium solani f. sp. glycines,” Bioresource Technology, Vol. 98, No. 7, 2007, pp. 1353-1358.

[21]   K. A. Nelson, P. P. Motavalli, W. E. Stevens, D. Dunn, C. G. Meinhardt, “Soybean response to preplant and foliar- applied potassium chloride with strobilurin fungicides,” Agronomy Journal, Vol. 102, No. 6, 2010, pp. 1657-1663.

[22]   G. E. Shaner, D. H. Scott, T. S. Abney, “Sudden-death syndrome in soybeans,” 2004. http://www.ces.purdue.edu/extmedia/BP/BP-58.pdf.