Detection of unknown toxic mycotoxins inAspergillus nidulans using a structure-activity approach
Mycotoxins are secondary metabolites of filamentous fungi that can cause various acute and chronic toxic effects in humans. Previous work by Büngeret al. exhibited that the cytotoxicityof Aspergillus nidulans, one of the most frequent toxigenic moulds in composting plants, could not be explained by its content of identified mycotoxins. The presence of additional mycotoxins or other toxic prinpiples was assumed, which may be detected by a structure-activity approach.
An HPLC-diode array detector method was used to separate and characterize the components of theA. nidulans-extract within 50 minutes/analysis. Aliquots of the extract were chromatographed and nine 5-minutes-fractions were collected and lyophilized. Rechromatography of aliquots of the residues confirmed the accuracy of the 5-minutes-cuts.
The cytotoxicity of these fractions was estimated in three cell lines (A-549, L-929 and Hep-G2) using the neutral red assay (NRU assay). Ethanol/dichloromethane (1:1, v/v) was proven to be a suitable solvent mixture with a low cytotoxicity. HPLC-fractions were dissolved in this mixture prior to the NRU assay. Three 5-minutes-fractions exhibited a strong cytotoxicity in this screening system and will be further analysed to identify the underlying unknown toxic principles.
KeywordsAspergillus nidulans mycotoxins sterigmatocystin cytotoxicity neutral red assay
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- 1.Bünger J, Möller A, Hallier E (2000) Cancer risks from microorganisms at the work place. Research Report 900, Schriftenreihe der Bundesanstalt für Arbeitsmedizin und Arbeitsschutz, Wirtschaftsverlag NW, Bremerhaven, 1–173Google Scholar
- 3.Göttlich E, Engesser KH, Bardtke D (1994) Emission von Pilzsporen in Müllverarbeitungsanlagen. Forum Städte-Hygiene 45: 321–323Google Scholar
- 5.Müller M, Bünger J, Hallier E (1999) Mycotoxin spectra as a biochemical parameter for occupational and environmental fungi exposure. In: Johanning E (ed) Bioaerosols, fungi and mycotoxins: health effects, assessment, prevention and control. Boyd Printing Company, Inc., Albany, NY, U.S.A., 418–422Google Scholar
- 8.Hinnendahl B (2005) Die Zytotoxizität von arbeits- und umweltmedizinisch relevanten Mykotoxinen in verschiedenen Zelllinien. Inaugural-Dissertation der Medizinischen Fakultät der Georg-August-Universität zu GöttingenGoogle Scholar