PREPARATIVE LC ISOLATION AND PURIFICATION OF FUMONISIN B-1 FROM RICE CULTURE

Procedures are presented for the production and rapid isolation of fum onisin B-1 (FB1) from fumonisin B-2 (FB2) and fumonisin B-3 (FB3), and for the purification of the mycotoxin FB1 from cultures of Fusarium m oniliforme MRC 826 grown on rice. The toxin was extracted from rice cu lture with acetonitrile:water (1:1; 5mL/g of culture material), filter ed, and reduced in volume on a rotary evaporator to remove the acetoni trile. A three-step liquid chromatographic (LC) method was developed f or the isolation of FB1, FB2, and FB3, and the purification of FB1. Pr eparative reversed-phase LC was used to isolate and partially purify t he FB1. In the first step, the extract was applied to a Waters Bondapa k PrepPak 500 C-18 reversed-phase cartridge and eluted with a methanol :water gradient. Fractions containing partially purified FB1 were coll ected, reduced in volume, and subjected to a second preparative LC pro cedure. The extract was applied to two Bondapak PrepPak cyano cartridg es, and isocratic elution with water:0.5% pyridine was used in the pur ification step. Recovery of the total FB1 was 97% from the first isola tion step and was 93% from the second purification step. Analytical hi gh-performance liquid chromatography and fast-atom bombardment/mass sp ectrometry were used in determining the purity of the FB1. Recovery of the high purity FB1 (95% or greater) was 77% or 2811 mg/3647 mg of st arting material.