Submitted to: Fumonisins in Food
Publication Type: Book / Chapter
Publication Acceptance Date: June 26, 1995
Publication Date: N/A
Interpretive Summary: A fungus Fusarium moniliforme produces toxic substances referred to as the fumonisins. These toxins are produced on corn and corn products, and pose both human and livestock health and performance risks. The fumonisins consist of at least two toxins fumonisin B1 and B2 (FB1 and FB2). It is very difficult to separate these two toxins into very pure forms, which is necessary for biological studies of their toxicity. This paper reports on a procedure to separate and purify FB1 from FB2. The fungus was grown on rice for 28-35 days, and this rice-fungus mixture extracted with a special solvent. The desired portion of this extract is applied to a special separator-type column, which separates FB1 from FB2. The two toxins are then purified by a series of other special separator-type columns. The FB1 toxin is purified by an additional series of separator-type columns. Finally, the toxin FB2 is further purified by a rotary type separator to remove other impurities. This procedure results in a purification of 93% and 85% or higher for FB1 and FB2, respectively. It is the utilization of this rotary-type separator by Unit scientists that results in the isolation of FB2 in very pure form, which now can be used in biological studies designed to determine the toxic effects on plants and animals.
Technical Abstract: Procedures are presented for growing Fusarium moniliforme MRC 826 on rice, separation of fumonisin B1 (FB1) from fumonisin B2 (FB2), purification of FB1 and preliminary procedures for purification of FB2. Mycotoxins were extracted from rice culture material with acetonitrile-water (1:1), filtered, and acetonitrile removed by a rotary evaporator. Preparative reverse phase liquid chromatography (LC) was used to isolate and partially purify FB1 and FB2. Extract was appllied to a C18 reverse phase cartridge. FB1 and FB2 were eluted from the cartridge by a gradient of water-acetonitrile at a flow rate of 30 mL/min. A second preparative LC procedure with two CN cartridges was used to purify FB1. The FB2 fraction was concentrated on a rotary evaporator to remove acetonitrile. Acetonitrile was added back in sufficient quantity to redissolve crystallin material in the fraction. An aliquot of the FB2 fraction was added to a centrifugal spinning silicic acid TLC plate. The TLC plate was washed at 3 mL/min with a linear gradient of (A) chloroform-acetone (4:3) and (B) methanol- acetone (3:3) to elute the FB2. Gradient starting conditions were 10% methanol and ending conditions were 50% methanol. This preliminary study using the centrifugal spinning TLC showed the procedure to have the potential to be useful for purification of FB2.