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Updated: Aug 14, 2026
Toxin Induction and Protein Extraction from Fusarium spp. Cultures for Proteomic Studies
Published on: February 16, 2010
NMR structural studies of fumonisin B1 and related compounds from Fusarium moniliforme
B A Blackwell1, O E Edwards, A Fruchier
1Mycotoxin Research Group, Plant Research Centre, Agriculture Canada, Ottawa.
Abstract:
Fumonisin B1 (FB1) is the primary mycotoxin produced by Fusarium moniliforme and appears to be responsible for the varied toxigenic effects associated with ingestion of this mold, particularly that of the inhibition of sphingolipid biosynthesis. Understanding the structure and biosynthesis of fumonisins is a key factor in determining structure/activity relationships. To this end, Nuclear Magnetic Resonance (NMR) methods have been used to identify various derivatives of FB1, both naturally occurring and synthetic. With accurate chemical shift assignments, NMR may be used to determine the level of impurities in toxicological grade FB1 preparations. Specifically enriched FB1 was prepared from F. moniliforme cultures using 13C-enriched acetate as well as several 13C-enriched amino acids. 13C NMR analysis indicates that the biosynthesis of fumonisins involves the addition of methionine-derived methyl functions, glutamate-derived tricarballylic ester functions and alanine to an 18 carbon hydrocarbon backbone that is likely polyketide in origin. With the goal of obtaining a crystalline compound for the determination of absolute configuration, several derivatives of FB1 have been prepared, and NMR analysis used to determine the relative and absolute configuration of the 10 stereocenters present in this molecule.
Insights
Fumonisin B1 (FB1), a mycotoxin, inhibits sphingolipid biosynthesis. Nuclear Magnetic Resonance (NMR) elucidated its biosynthetic pathway and stereochemistry, aiding structure-activity relationship studies.
Area of Science:
- Mycology
- Biochemistry
- Organic Chemistry
Background:
- Fumonisin B1 (FB1) is a mycotoxin from Fusarium moniliforme.
- FB1 causes toxic effects, notably inhibiting sphingolipid biosynthesis.
- Understanding FB1 structure and biosynthesis is crucial for structure-activity relationship studies.
Purpose of the Study:
- To elucidate the biosynthetic pathway of FB1 using isotopically enriched precursors.
- To identify FB1 derivatives and determine their configurations using Nuclear Magnetic Resonance (NMR) spectroscopy.
- To establish accurate chemical shift assignments for impurity analysis in toxicological FB1 preparations.
Main Methods:
- Preparation of specifically 13C-enriched FB1 from F. moniliforme cultures using 13C-acetate and 13C-amino acids.
- 13C NMR analysis to determine the origin of biosynthetic components.
- Synthesis of FB1 derivatives for NMR analysis to establish relative and absolute configurations.
Main Results:
- FB1 biosynthesis involves incorporating methionine-derived methyl groups, glutamate-derived tricarballylic ester groups, and alanine.
- An 18-carbon hydrocarbon backbone, likely polyketide-derived, forms the basis of FB1.
- NMR analysis confirmed the relative and absolute configurations of the 10 stereocenters in FB1 derivatives.
Conclusions:
- NMR spectroscopy is effective for elucidating mycotoxin biosynthesis and stereochemistry.
- The study provides insights into the polyketide-derived backbone and specific functional group additions in FB1 biosynthesis.
- Accurate structural and stereochemical data from NMR aid in understanding FB1's toxicological mechanisms and structure-activity relationships.
