3 Preparatory Isolation of Mycotoxins from Solid Phase Fungal Cultures

Mycotoxins are a large group of secondary fungal metabolites possessing significantly different chemical and physical properties. Because of this diversity, no general procedures can be developed for the isolation and purification of all of the different mycotoxins. The aim of this chapter is to present a procedure that has been successfully applied to the isolation and purification of one mycotoxin group (the fumonisins) which can be adapted to the preparation of many of the other mycotoxins. The fumonisins are water soluble and were missed in many of the early attempts at isolation of the toxic agents produced by Fusarium verticillioides (= F. moniliforme). These metabolites were not isolated and identified until 1988 (1 ). Most of the mycotoxins identified before this time were extracted from the culture media with organic solvents such as chloroform, acetone, ethyl acetate, methanol, and so on (2 –11 ). Methods using aqueous-organic phase extractants have more versatility and can be made more selective for a particular group of mycotoxins by adjusting the ratio of water to organic solvent.