Mycotoxins functional groups

A second stereoselective total synthesis of ( )-eremophilone (243) has been accomplished using 7-epinootkatone (242) as intermediate.109 The latter compound was synthesized from (—)-/3-pinene (241) by modification of the published procedure"0 and subsequently converted into eremophilone (243) by the series of functional-group transformations shown in Scheme 30. A mycotoxin isolated from Penicillium roqueforti has been assigned the highly oxygenated eremophilane structure (244) on the basis of chemical and spectroscopic evidence."1 The structure and... 

The mycotoxin patulin was synthesized via the oxidation of a disubstituted furan in the laboratory of M. Tada. The required 2,3-disubstituted furan was conveniently prepared via the Feist-Benary reaction of acetonedicarboxylic acid dimethyl ester and chloroacetaldehyde in the presence of pyridine. Subsequent functional group modification and oxidation of this furan finally gave the natural product. 

All trichothecenes include the tricyclic 12,13-epoxytrichothec-9-ene core, 370. Based on this structure and its substitution pattern, the mycotoxins have been classified into four types, A (371), B (372), C (373), and D (374), by Ueno et al. Type A (371) can have a hydroxy group, an ester, or no functional group at C-8. Type B (372) possesses a carbonyl group at C-8, type C (373) has an epoxide function at C-7/C-8, and type D (374) mycotoxins are macrocyclic trichothecenes. Included among these four types there are some exceptions, which cannot be grouped accurately using this classification. Other classification systems for trichothecenes were proposed by Jarvis et al. (312) and Tamm et al. (313), but these will not be further discussed in this volume (Fig. 8.3). 

Interest in the mycotoxins of Aspergillus species continues, and the structures of several metabolites have been elucidated. Fumitremorgins A and B (FTA and FTB) are accompanied in A. fumigatus by six related indole-containing metabolites (FTC to FTH) which, however, appear to have no detectable tremorgenic properties. The first of these, FTC, exhibits very similar functionality and spectroscopic properties to tryptoquivaline, although the two compounds are not identical. However, FTC acetate and tryptoquivaline acetate (33) are identical hence FTC (34) differs from tryptoquivaline (35) solely in the position of the acetate group.31... 

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