Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 1997
Publication Date: N/A
Interpretive Summary: Toxic substances, named fumonisins are produced by a fungus Fusarium moniliforme. These toxins are produced on corn and corn products and pose both human and animal health risks. There are at least three toxins, fumonisins B1, B2, and B3. It is very difficult to separate these three toxins into very pure forms. This is necessary for biological studies of their toxicity. This paper reports on the isolation of fumonisins B1, B2 and B3 and the purification of fumonisin B2. The fungus was grown on rice for 28 to 35 days and this rice fungus mixture was extracted with a chemical solvent. The chemical solvent that contained the extracted fumonisins was passed through a separator type column that separated the fumonisins B1, B2 and B3 from each other. The fumonisin B2 toxin is purified by a rotary type separator to remove other impurities. This procedure results in a purification of 90% or greater for fumonisin B2. The use of this rotary-type separator results in the isolation of fumonisin B2 in very pure form, which now can be used in biological studies to determine the toxic effects on plants and animals.
Technical Abstract: Procedures are presented for the production, isolation, and purification of the mycotoxin fumonisin B2 from cultures of Fusarium moniliforme MRC 826 grown on rice. Fumonisins B1, B2 and B3 were extracted with acetonitrile:water, the extracts were filtered and reduced in volume with a rotary evaporator. Fumonisin B2 was isolated from the other fumonisins by preparative reverse phase liquid chromatography (LC). Fractions that contained fumonisin B2 were concentrated to remove acetonitrile and the remaining water fraction was frozen and freeze dried. The freeze dried material was dissolved in a minimum amount of methanol and separated by preparative, centrifugally accelerated, radial, thin-layer chromatography on a silica gel coated plate. An applicator that precisely controlled the rate of application of extract to sorbent material was used to minimize the width of the band of extract. Fractions were eluted from the spinning plate with a linear gradient of (A) chloroform:acetone (4:3) and (B) methanol:acetone (1:1) applied at a rate of 3mL/min. Gradient starting conditions were 10% B and 90% A and ending conditions were 50% A and B. Fractions that contained fumonisin B2 were combined and were freeze dried. Recovery of purified fumonisin B2 was 90% that of the starting extract, and purity as determined by HPLC light scattering detection was 90% or greater.