BIOSYNTHESIS OF DESTRUXINS

L-[Me-C-13]-Methionine, sodium [2-C-13]acetate and sodium [1,2-C-13]ac etate were incorporated into destruxins A, B and E by the entomopathog enic fungus Metarhizium anisopliae. NMR analysis established that meth ionine is involved in the N-methylation Of L-valine and L-alanine, and that one intact acetate unit participates in the biosynthesis of the -CH(OH)-COOH fragment of the hydroxy acid moiety. The presence of two acetate units in proline and isoleucine agrees with the accepted bioch emical schemes.